Exercise 10: Visual Sense and the Nervous System
Contemporary
Biology Online Learning Objectives
•
•
•
•
•
•
Learn the types of sensory receptors important for homeostasis
Identify the different parts of the human eye and understand their functions
Explain blind spot, farsightedness, nearsightedness, and astigmatism
Perform an online colorblindness test
Learn about the science of some optical illusions
Test a hypothesis, analyze data and draw conclusions about visual reaction time
Materials from the Student – Internet access, yardstick or tape measure,
textbook; 3–6 volunteer test subjects for the visual reaction time experiment
Introduction: The sensory nervous system receives different stimuli and sends
nerve impulses to the central nervous system (the brain and spinal cord), where
various parts of the brain will be alerted and will determine how to respond to
maintain stable homeostasis. Our ability to touch, hear, taste, smell and see is
determined by sensory receptors connected to a network of neurons communicating
with our brain via the spinal cord. Scientists use different approaches to learn how
receptors and neurons communicate with each other and what causes certain
sensory problems, such as chronic pain, hearing loss, blindness and other
conditions.
Five senses: Sight, hearing, smell, taste, touch
Types of sensory receptors that detect the internal body environment:
•
•
•
•
•
•
Chemoreceptors detect chemicals in the environment or the blood (e.g., CO2
levels).
Mechanoreceptors respond to touch and pressure in the skin, hair, and inner
ear.
Nociceptors detect pain, usually near the surface of tissues.
Photoreceptors in the eye are the rods and cones. Rods detect dim light (black
and white) and are located on the periphery of the retina; cones detect color
and are located in the center of the retina.
Proprioceptors detect body position and allow detailed skeletal movements.
Thermoreceptors detect cold and heat.
This lab exercise focuses on the functional anatomy and physiology of the eye.
Anatomy of the Human Eye
Read page 289 in Chapter 11.21 of your textbook for more background facts, and
visit this interactive tutorial about vision:
Figure 1: Human Eye
In Your Blackboard Lab Report
Lab Report Question 1. Complete the following matching activity to reinforce your
knowledge about the eye. (Other eye structures could be on a future lab quiz so
review the basic eye anatomy.)
Eye
Answer
Description of the Anatomical Structures and
Functions
1. Cornea
C
2. Lens
E
3. Iris
D
4. Retina
A
5. Blind Spot
B
A. Light sensitive layer of cells (with rods and cones);
connected to the brain via optic nerve; known as the eye’s
“camera film”
B. Where no photoreceptors (no rods and no cones) are
found; where the optic nerve exits the retina; an image on this
location is not seen
C. Is the first to bend the incoming light into the eyes; is a
clear outer covering that protects the lens and iris; can get
infected or scratched
D. Circular muscle that controls how much light enters the
eye; its pigmentation is responsible for “eye color”
E. Flexible structure that can change its shape to focus on
objects near and far; clouding of this structure results in
cataract formation
Common Vision Problems
•
A nearsighted person cannot clearly see objects that are located far away.
•
A farsighted person cannot see objects that are very close to their eyes.
•
A person with astigmatism has blurry vision because of an abnormally
curved cornea. Astigmatism often occurs together with nearsightedness or
farsightedness.
In Your Blackboard Lab Report
Lab Report Question 2. What causes these visual conditions? Analyze the
following diagrams below to complete this online activity in Blackboard.
Eye Condition
1. Astigmatism
2. Farsightedness
3. Nearsightedness
4. Normal vision
Answer
D
A
B
C
Explanation
A. Light is focused behind the retina
B. Light is focused in front of the retina
C. Light is focused directly on the retina
D. Light is focused on multiple places on the retina
Thus corrective lenses are required to adjust specific vision problems.
To Learn More: Learn about Lasik Surgery
http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/SurgeryandLif
eSupport/L ASIK/default.htm
• Lab Activity: Visual Tests and Experiments – Record your results in this
handout
•
Take the Online Color Blind Test
Dr. Shinobu Ishihara developed a color perception test in 1917 to identify redgreen color blindness, which is the most common type of color blindness. Lack of
or dysfunctional cone photoreceptors are some causes of color blindness. The
genes for the red and green visual pigments (photoreceptors) are on the X
chromosome.
•
•
•
Go to http://www.eyes-and-vision.com/color-blindness-test.html
Record the numbers you can see inside each circle in the data table below.
Check your answers with the website.
IMPORTANT! If you cannot see the numbers, then you may be colorblind;
however, consulting a vision care professional is recommended since this
online activity is not diagnostic. Note that the results can be affected by the
colors shown by the computer monitor and the lighting conditions.
A
Number
Observed
•
25
B
6
C
45
D
8
E
56
F
29
Visual Acuity (Ability to Focus on Sharp Details)
Proper vision includes the eyes, brain, and the visual pathways working in
collaboration.
The Dutch eye doctor Dr. Herman Snellen created an eye chart in the early 1860s
to measure visual acuity, or the ability to focus on sharp details. The Snellen
fraction 20/20 is used to define “normal” vision but not “perfect” vision.
Generally, as the bottom number of the Snellen fraction increases, the worse the
person’s visual acuity. A fraction of 20/40 indicates that someone can read at 20 feet
away what a person with normal vision could read at 40 feet away.
Thus, nearsighted people without corrective lenses will have to stand closer to the
Snellen chart. Sometimes one eye has a better visual acuity than the other.
Memorization of the letters on the Snellen chart may occur with repeated use of
the same Snellen chart. Use a chart with different letters or numbers if a person
repeats the test too often.
Instructions
•
First, complete the 4 online visual screening tests provided by
Sterling Optical https://devlynoptical.com/online-vision-test/
•
Record your observations and results in the data table provided
below.
Name of the Visual Test
Record your online vision results
DISTANCE
READING
ASTIGMATISM
EYE HEALTH
(RETINAL OR
MACULAR
DAMAGE)
I took the test 3 times and the results weren’t sent to me, but on the screen it said
that my reading power is +2.00. Left eye was at 87.5% excellent and 75% very
good.
• Astigmatism: Blurred vision may occur if the cornea or lens is shaped
irregularly, which prevents light from focusing properly on the retina. As a result,
vision becomes blurred at any
distance. Astigmatism is
a very common vision condition. Most people have
some degree of astigmatism.
Optometrists use an astigmatism chart to
determine if the condition is present.
No astigmatism is present if all the radiating lines
appear equally dark and distinct if the refracting
surface is not distorted.
Instructions:
Astigmatism is present (to some degree) if some of the lines are blurred and
appear less dark than others.
• Focus on the center of the radiating image with each eye separately
and note the appearance of the radiating lines. Did you detect
astigmatism?
• Record your results (yes or no): Right eye: yes
Left eye: no
DATA ANALYSIS: Let’s review what you learned about the blind spot,
colorblindness, visual acuity (Snellen fractions), and astigmatism. Please answer the
following questions based on your results and the background information provided.
Write in complete, coherent sentences.
Lab Report Question 3. Did you detect any form of colorblindness? And what 2
challenges do you think color-blind persons face in everyday life?
I did not detect any colorblindness in my exams. I think that 2 challenges
colorblind people face in everyday life might be driving because of the stop lights and
another one is not being able to cordinate colofl outfits
Lab Report Question 4. Do you have normal vision (20/20) in each eye based on
the online eye exam? Compare your Snellen fraction to the normal standard of
20/20. What conclusions can you make about your results? Use this website to
answer to determine your fraction. http://www.allaboutvision.com/eye-test/snellenchart.pdf
I dont have 20/20 vision, I believe I have 20/80.
Lab Report Question 5. Which vision results did you find were unexpected or most
interesting? Explain your reasons.
I have a stigma in my right eye, which I already was aware of because of my eye
exams.
• Science of optical illusions
Read the BBC news article that provides fun, optical illusions and describes how
scientist Beau Lotto is learning how our brain process multisensory information.
Go to http://www.bbc.co.uk/news/magazine-11553099 to see some examples.
Be sure to watch the video clip “How the brain thinks a rubber glove is a real hand,”
which is an optical illusion that demonstrates neuroplasticity.
Lab Report Question 6.
a. Which optical illusion example did you like the best and why?
I like the Jungle Scene illusion becasue you cant see the animal in the black and white
portion but you can clearly see it in the colored version.
To Learn More
Many more optical illusions are available at http://www.michaelbach.de/ot/
Test your ability to see afterimages:
http://www.exploratorium.edu/exhibits/bird_in_a_cage/bird_in_a_cage.html
•
Lab Activity: Online reaction time experiment
The human body
communicates and responds to the environment using 3 types of neurons: sensory
neurons, association neurons (interneurons), and motor neurons as described on
textbook pages 288 – 289. To conclude this lab exercise on how the eye works and
communicates with the nervous system, you will perform an experiment to test visual
reaction time. A reaction time is based on
a voluntary
response, whereas a
reflex is an involuntary
response. A directional
flow of information in a
reaction response
starts with the stimulus
(e.g., pin prick of the
finger) by the sensory
receptors, which
communicate
with the sensory nerves that connect to the central nervous system (CNS which is the
spinal cord and brain); after which the brain sends commands to the motor neurons
which control the effector responses, such as the voluntary muscles (e.g., stepping
on the car brake after you see a yellow or red traffic light signal).
The faster a person responds to a visual cue (e.g., color change of a traffic light) the
lower the reaction time will be in units of time (e.g., seconds). However, there are
multiple factors influencing why a person might have different reaction times to the
same visual cue on any given day. For example, some contributing factors to slower
reactions time might be distractions (e.g., texting; loud noises), fatigue, time of day
(e.g., working morning or night shifts), medications, neural disorders, vision
problems, and more.
Purpose: To determine a person’s reaction time by clicking a mouse button in
response to a visual cue using an online reaction test website
Question: What factors influence visual reaction time? Select an independent
variable (a condition or factor) that you think will influence a person’s reaction time
to a random visual signal. For example, choose to test the effect of one of the
following independent variables:
•
•
•
•
•
•
Age (older individuals vs. younger individuals)
Time of day (morning vs. night)
Distraction (no distractions vs. distractions present such as loud background
sounds)
Alertness
Fatigue
Other factor that you find relevant
Instructions
• Preform the Online reaction time test . Go to
http://getyourwebsitehere.com/jswb/rttest01.html
(a screen shot is provided for you on the next page so you know what to
expect).
• Follow the directions for the online reaction time test in the text box provided.
IMPORTANT:
Copy these online results into your lab handout to calculate the group
If you could repeat this visual reaction time experiment to get more accurate results, briefly explain
what you would change and briefly explain why.
If I had to repeat this experiment again I would focus more on the big button then the green
light. By that, I was starring at the green light and having a late reaction to clicking the button.
What kinds of information can you learn about a person, or a group of people, by testing their visual
reaction time?
You can learn if they’re fit to drive and maybe play sports without reacting slow
and getting injured.
Test Number
Reaction Time
1
0.403
2
0.373
3
0.387
4
0.346
5
0.412
AVG
0.3842
Exercise 8: Vital Signs and Medical Lab Tests
Contemporary Biology Online
Learning Objectives
•
•
•
•
•
Learn how to measure basic vital signs – pulse rate, breathing rate, blood pressure
Explain the 2 numbers used to measure blood pressure – systolic vs. diastolic pressure
Understand high blood pressure (hypertension) and its causes
Learn some of the routine screening tests used to evaluate overall health: blood test, urinalysis
Analyze clinical lab test results against normal standards – Pap smear, PSA test, blood
cholesterol profile, and blood cell count (red blood cells, white blood cells)
Materials from the Student — Computer, internet access, watch (or clock), textbook
INTRODUCTION
The human body is incredible! Every second, hundreds of trillions of reactions occur within trillions of
cells, allowing tissues, organs, and organ systems to maintain life. This narrow range of acceptable
parameters (temperature, pH, heart rate, etc.), is constantly kept in balance, or homeostasis.
To maintain our health and well-being, we need to be sure that we are getting proper nutrition and
rest, exercising and maintaining a healthy lifestyle and weight, and doing our best to prevent disease.
When we are well, we pay little attention to the inner workings of our bodies. When we are ill or in
pain, we are made acutely aware of our internal operating system and its many components. One
should visit the doctor for routine yearly check-ups and when we are ill or injured, to ensure our
continued good health.
PART 1: UPON ARRIVAL AT THE DOCTOR’S OFFICE: You’ll need to fill out some paperwork. In
addition to your name, date of birth, and address, you may be required to show your insurance card
and photographic identification (driver’s license, etc), if you have them, before being seen. You’ll need
to list contacts and who can share your records, as well as signing a HIPA (Health Information
Protection Act of 2005) form to keep your personal information private.
Your role is of utmost importance: communication. Tell the doctor your concerns, answer lifestyle
questions honestly, and be sure to ask any questions you may have before leaving.
Be prepared to answer the following questions asked by your doctor and health care provider:
• Why have you come in?
• If not for a routine check-up, what is your history of present illness? Do you have a cold, a
fever, injury, or pain?
• What is your past medical history? Describe in detail any prior surgeries, vaccinations, major
infections, allergies (immune system reactions to food or mediation, from mild rashes to
critical breathing problems), and diseases (abnormal condition from external sources, such as
bacterial infections, smoking, etc.) or disorders (abnormal condition from internal origins, such
as a genetics, etc) you already have.
© Northampton Community College
1
•
How much do you know about your family medical history? Are your parents or grandparents
affected by heart disease, diabetes, cancer, high cholesterol, or inherited illnesses? You will be
asked these questions to ascertain if you are a candidate for genetic testing.
To Learn More: For more information about HIPA, please see http://www.hhs.gov/ocr/privacy/
PART 2: VITAL SIGNS
A nurse or technician will provide the preliminary examination by collecting signs (objective; can be
measured or observed; deformity or open wound) and symptoms (complaints; subjective; pain or
nausea). Vital signs are ways to measure our current physical state. If our vital signs are out of
normal limits, they indicate that something may be wrong. **Keep in mind, however, that some
individuals’ vital signs are normally a bit different from what we consider to be typical! **
➢ Respiration: We need to breathe in oxygen and give off carbon dioxide continuously. Each time
we breathe in and out is one respiration. The average respiratory rate (respirations per minute) is
about 12 to 20 breaths per minute. Respiration rate (breathing rate; measured in
breaths per minute) is determined by observing
the chest rise (during inspiration) and the chest
falling (expiration). Oxygen gas (O2) is inhaled
and carbon dioxide gas (CO2) is exhaled. The gas
exchange occurs at the interface between the
capillary network (circulatory system) and the alveoli
sacs (respiratory system); thus, blood transports the
gases around the body. See diagram insert to review.
Respiration rate can change with age, level of activity, lung
capacity, dehydration, altitude, drug overdose, and overall lung health.
➢ Body temperature: Every day, chemical reactions inside us keep us alive (collectively referred to
as metabolism) and generate heat. The measure of this heat is our body temperature, usually
98.6oF or 37oC. A fever is an elevated temperature unrelated to environment or exertion, and it
can indicate that an infection is present. Normal human body temperature depends upon the place
in the body at which the measurement is made, the time of day and level of activity of the body.
➢ Pulse: When your heart pumps blood through your arteries, we can feel it as a wave, or pulse,
which is triggered by the heart’s pacemaker called the sinoatrial node. The heart of the average
resting person beats about 60 to 100 times each minute. A pulse rate is measured in heart
beats per minute. Some fit individuals may have a slower resting pulse rate, while stress,
exertion, and caffeine make the heart beat faster. We can feel our pulse at superficial arteries in
our neck (carotid), wrist (radial), inner elbow (brachial), and groin (femoral). Pulse rate changes
with age, body weight, physical training, emotion, activity level, body temperature and overall
heart health.
© Northampton Community College
2
➢ Blood pressure (BP): The force of the blood in the arteries is measure as blood pressure. We
measure blood pressure with a manual or digital apparatus called a sphygmomanometer. To use
a manual sphygmomanometer, a rubber balloon within a flat fabric sleeve (called a “cuff”) is
wrapped around the upper arm and inflated. As the cuff deflates, we measure when the pulse
returns to the squeezed arm, and then when we can no longer detect it. These two numbers are
recorded as a fraction. Ideally, 120/80 mmHg (millimeters of mercury) is considered normal, but
there is dramatic variation in ‘normal’ blood pressure. BP reading can vary by age, time of day,
level of physical activity, and existing chronic or short-term illnesses.
o The top number, the systolic pressure, records the force of the heart actually beating.
The maximum systolic pressure occurs when the heart contracts (“squeezes”) blood
out into the arteries.
o The bottom number, the diastolic pressure, is the left-over pressure while the heart is
resting between beats and filling with blood.
Everyone’s blood pressure varies throughout the day. Hypertension, known as the ‘silent killer,’ is
chronic high blood pressure, which may lead to heart disease and stroke if untreated.
Low blood pressure, called hypotension, may cause one to feel dizzy or black out.
To Learn More about symptoms and causes of low blood pressure (hypotension) go to
http://www.mayoclinic.com/health/low-blood-pressure/DS00590/DSECTION=causes
© Northampton Community College
3
PART 3: PHYSICAL EXAMINATION
After recording your vital signs, the nurse or doctor may also perform the following:
•
•
•
•
Observation: Note skin color, apparent discomfort, body positioning, eye appearance, etc.
Auscultation: A stethoscope is used to listen to the sounds of your lungs, heart, and bowels.
Percussion: Sometimes tapping on your torso will help discover a problem. If normal, air-filled
tissue has been displaced by fluid or by trapped air, percussion will generate a sound different
than expected.
Palpation: The neck, abdomen, and any painful limbs are palpated (felt) for any sore spots,
deformity, or swelling.
PART 4: COMMON FOLLOW-UP RECOMMENDATIONS: Your doctor may suggest routine blood
tests for blood chemistry, cholesterol, and total blood counts; imaging for a painful body region (X-ray,
MRI, CT scan, etc.); and annual check-ups, which for females includes a PAP test for cervical cancer,
and a PSI test to screen for prostate cancer in males. Other follow-ups may include dental cleaning
and check-up, urine sample analysis, bone density test for osteoporosis, and/or calculating body mass
index (BMI) to measure body fat and obesity.
Lab Activity – Record Your Vital Signs
Respiratory Rate: One inhalation (breathing in) and exhalation (breathing out) equals one
respiration. Please review “Essential Biological Process 25A: Breathing” and read The Mechanics of
Breathing on pages 262 – 263 in your textbook. To measure your respiratory rate,
1. Breathe normally at rest, but not after any exercise.
2. Count the number of complete respirations (breathing in and out) over one minute period, or
count each complete respiration for 15 seconds and multiply the number by 4.
If you have a mirror, sit or stand in front of the mirror. Watch the number of times your chest rises and
falls. Or, place your hand on top of your chest to count the number of complete respirations.
3. Repeat two more times. Then calculate your average respiration rate by adding the 3 results
and divide by 3.
4. Record your data in Table 1.
Table 1. My Respiration Rate at Rest
Vital Sign
Respiration rate
Normal Ranges Reading #1
12- 20 breaths
per minute
© Northampton Community College
25
Reading #2
23
Reading #3
20
Average
22
4
Pulse Rate: The pulse rate is the number of heartbeats per minute. To measure
your pulse rate,
1. Turn your left hand palm-side up. Then place the first two fingers of your
right hand along the outer edge of your left wrist just below where your
wrist and thumb meet.
2. Slide your fingers toward the center of your wrist. You should feel the
pulse between the wrist bone and the tendon.
3. Press down with our fingers until you feel your pulse. Do not press too hard, or you will not be
able to feel the pulsation. Feel free to move your fingers until the pulse is
easiest to feel.
4. Continue to feel your pulse for a one minute, or count each pulsation for
15 seconds and multiply the number by 4. Concentrate on whether the
beats are evenly spaced, or whether they are erratic, with missed beats,
extra beats, or beats that are too close together.
Table 2. My Pulse Rate at Rest
Vital Sign
Pulse rate
Normal Ranges Reading #1
60 – 100 beats
per minute
80
Reading #2
92
Reading #3
94
Average
88
*Recommendation: Visit your doctor annually to monitor your blood pressure and your other health concerns.
In Your Blackboard Report:
Lab Report Question 1. At rest, we hope your averages for both vital signs were within the normal
ranges listed in Table 1. Why is it important to take multiple readings, and then calculate the average,
and not rely on one reading of each vital sign?
It is importatnt to take multiple readings as your breathing changes. My first reading I believe I was concentrating
too much on the breathing and was breathing faster. But the other readings I was able to relaxe more to capture my
natural breathing.
Lab Report Question 2. Would increasing your physical activity from sitting to brisk walking (or
jogging) increase or decrease your respiration rate and pulse rate? Why? Briefly explain your
reasoning. Phsycial activity would increase your respiration and pulse rate. As your heart rate increase so does
your pulse and your breathing as lungs are working more. You begin breathing faster and harder to make sure
oxygen reaches the blood and carbon releases.
© Northampton Community College
5
HINT: Visit “pumping action” for clues:
http://science.nationalgeographic.com/science/health-and-human-body/human-body/heart-article/
© Northampton Community College
6
Lab Activity – Measuring Blood Pressure
Instructions: Watch the following animations:
In Your Blackboard Lab Report: Please answer the questions below:
Lab Report Question 3. Choose from (A. right; B. left; or C. central) to fill in the sentence below
The human heart has four heart chambers (see diagram below). Deoxygenated blood enters the
first chamber of the heart, called the left atrium. The sinoatrial node, the heart’s “pacemaker,”
is also located in the right atrium and sends out an electrical signal to make the heart beat
rhythmically.
Lab Report Question 4. Choose from (A. ventricle; or B. atrium) to fill in the sentence below
Both upper atrium chambers contract together and empty (push) blood into the lower ventricle.
Lab Report Question 5. Choose from (A. ventricle; B. atrium; C. Systolic or D. Diastolic) to fill in the
sentence below
The ventricle contract together to push blood into the arteries away into different parts of the body.
This heart contraction is the source of the blood pressure reading known as the diastolic pressure.
© Northampton Community College
7
What is Hypertension?
According to the National Heart, Lung and Blood Institute, 1 in 3 persons living in the United
States has high blood pressure (also known as hypertension). One of the most dangerous
aspects of hypertension is that you may not know that you have it – this is why it is called the silent
killer. In fact, nearly one-third of people who have high blood pressure don’t know it.
The only way to know if your blood pressure is high is through regular checkups. This is especially
important if you have a close relative who has high blood pressure.
Some symptoms of high blood pressure include severe headache, fatigue or confusion, vision
problems, chest pain, difficulty breathing, irregular heartbeat, blood in the urine, and pounding in your
chest, neck, or ears. If you have any of these symptoms, see a doctor immediately; you could be
having a hypertensive crisis that could lead to a heart attack or stroke.
If left untreated, hypertension can lead to stroke, heart failure, coronary heart disease, kidney failure,
and eye problems.
Table 3. The American Heart Association’s description of the range of blood pressures considered
normal and those that indicate increasing levels of hypertension.
Blood Pressure
Category
Normal
Systolic
mm Hg (upper #)
Diastolic
mm Hg (lower #)
less than 120
and
less than 80
Prehypertension
120 – 139
or
80 – 89
High Blood Pressure
(Hypertension) Stage 1
140 – 159
or
90 – 99
High Blood Pressure
(Hypertension) Stage 2
160 or higher
or
100 or higher
Hypertensive Crisis
(Emergency care needed)
Higher than 180
or
Higher than 110
© Northampton Community College
8
How are Cholesterol and Other Lipids (Fats) Involved in Coronary Heart Disease?
Instructions: Go to the following website:
http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=hdlldl
Watch “Cholesterol Score” and “Cholesterol and Coronary Heart Disease” from the menu options,
then answer the matching questions below.
Lab Report Question 6. Complete the following matching questions after watching the animations.
Descriptions
Answer
Choices
1. The “bad” cholesterol; this lipoprotein deposits
cholesterol in the artery walls causing
atherosclerotic plaque formation
F
A. Cholesterol
2. The “good” cholesterol; this lipoprotein removes
cholesterol from the blood stream and artery
walls
D
B. Triglycerides
3. Are stored in fat cells and used as energy, but
excessively high levels are associated with
other health conditions (e.g., being overweight)
A
C. Coronary heart disease
4. HDL + LDL + Triglyceride = Number
E
D. High density lipoprotein
(HDL)
5. The process that causes arteries to stiffen,
harden; may lead to a heart attack
C
E. Total Cholesterol
Score
6. Narrowing of the arteries of the heart reducing
proper flow of oxygen rich blood
G
F. Low density lipoprotein
(LDL)
7. Used to form cell membranes, aid in digestion,
make hormones
B
G. Atherosclerosis
© Northampton Community College
9
What are the Signs of a Heart Attack?
Coronary heart disease (CHD)—the most common type of heart disease—is the #1 killer of both men
and women in the United States. Coronary Heart Disease (CHD) occurs when plaque builds up on
the inner walls of your
coronary arteries. These
arteries carry oxygen-rich
blood to your heart. When
plaque builds up in the
arteries, the condition is
called atherosclerosis.
Plaque is made up of fat,
cholesterol, calcium, and
other substances found in
the blood. Over time, plaque
can harden or rupture
(break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich
blood to the heart. This can cause chest pain or discomfort called angina. If the plaque ruptures, a
blood clot can form on its surface. A large blood clot can mostly or completely block blood flow
through a coronary artery. This is the most common cause of a heart attack. Over time, ruptured
plaque also hardens and narrows the coronary arteries.
In the United States, 1 in 4 women die from heart disease. Learn about differences in heart attack
symptoms between men and women at this web site. http://www.webmd.com/heartdisease/news/20050218/men-vs-women-confusion-over-heart-symptoms
COMPREHENSION CHECK: According to the web site, what are the most common symptoms
characterizing men’s heart attacks and women’s heart attacks?
a. Men have cold sweat; women have shortness of breath.
b. Men have lightheadedness; women have cold sweat.
c. Men have chest pain; women have indigestion.
d. Men have indigestion; women have chest pain.
To Learn More about heart disease in women and to educate others, visit
http://www.womenshealth.gov/heart-health-stroke/signs-of-a-heart-attack/,
© Northampton Community College
10
Medical Laboratory Panels
In addition to measuring your vital signs, healthcare providers may request specific laboratory tests to
detect, treat, or monitor certain health conditions or diseases. For example, urine, blood, bodily
substances and other tissues may be tested for certain chemical profiles or cellular observations.
Normal values vary from person to person and are presented as normal ranges of expected values.
Laboratory test results can be affected by many factors, such as intake of specific foods, medications,
gender, age, race, medical history, general health and even variations among laboratories or their
techniques. You will often be required to fast at least 8 hours before having a blood test.
Blood chemistry panel: This panel examines the complete blood count (CBC); the lipid profile, and
factors in your blood that may indicate kidney or liver problems.
Lipid profile: Lipids do not dissolve in water but dissolve in other substances. The lipid profile
evaluates the risk for cardiovascular disease associated with atherosclerosis (arterial plaque or
hardening of the arteries). The following lipid components are measured:
•
•
•
•
•
Total Cholesterol: measures all of the cholesterol in all the lipoprotein particles
Triglycerides: another form of fat; these lipid molecules reform from digested fats
HDL Cholesterol: called “good cholesterol” because it removes excess cholesterol and
carries it to the liver for removal; higher the HDL, the better
LDL Cholesterol: called “bad cholesterol” because it deposits excess cholesterol in walls
of blood vessels, which can contribute to atherosclerosis
Total Cholesterol/HDL Ratio: A higher ratio indicates a higher risk of heart disease; a
lower ratio indicates a lower risk
Goals of healthy cholesterol management are to
➢ Increase HDL (“good”) cholesterol levels
➢ Decrease LDL (“bad”) cholesterol
➢ Do regular exercise, eat low-fat foods and take medications
Complete blood count (CBC) is used to detect a
wide range of disorders, including anemia, infection
and leukemia. The following blood components are
analyzed: oxygen-transporting red blood cells
(RBCs), infection-fighting white blood cells (WBCs);
the amount of the oxygen transport protein called
hemoglobin; blood-clotting platelets, and the
hematocrit (ratio of red blood cells to fluid blood
plasma).
Urine test can check for color, pH, clarity, odor,
microscopic sediments, and among other substances. High glucose sugar levels in urine can
indicate diabetes or damaged kidneys.
Pap Smear in females can detect early signs of cervical cancer by sampling and analyzing cells
from the cervix, which is located between the base of the uterus and the vaginal opening (birth
© Northampton Community College
10
canal). The Pap test can identify potential infections and abnormal cervical cells (see textbook
pages 281 – 284 for an explanation of the female reproductive system).
Prostate Specific Antigen (PSA) test in males detects the PSA protein, which produced by the
prostate gland and can be detected in blood. The prostate is gland found at the base of the
bladder (see page 280 in your textbook). Higher PSA levels may indicate an inflamed or enlarged
prostate or the presence of prostate cancer. However, some prostate cancer cases may have no
elevated PSA, so careful consultation with the doctor is critical to making important health
decisions.
PSA – Prostate Specific Test (Men only)
Pap Smear Test (Women only)
Bladder
Lab Activity: Jack and Jill have gone to the doctor for their annual check-up.
Jack is 47 years old; he is 5’10” tall and weighs 205 pounds.
Jill is s 47 years old; she is 5’2″ tall and weighs 115 pounds.
Some results from their check-up and lab tests are shown below. Based on the Normal Test Results
values listed in the chart below, which patient’s lab results are normal, and which are abnormal?
Jack’s Test Sample
Blood Pressure
Blood chemistry: Cholesterol
Blood chemistry: HDL
Blood chemistry: LDL
Blood chemistry:
Total cholesterol to HDL ratio
Red blood cell count
White blood cell count
Urinalysis
Normal Test Result
Less than 120/80
Less than 200mg/ml
Over 60 mg/dl
100-129 mg/dl
5:1 to 3.5:1
Patient’s Lab Result
138/83
249 mg/ml
57 mg/ml
174 mg/dl
4.4:1
4.8-5.4 million/cc
4300-10,800/cc
No glucose or ketones
Prostate Specific Antigen
4 ng/ml
5.0 million/cc
5,000/cc
Some glucose and
ketones
7 ng/ml
© Northampton Community College
Normal or
Abnormal?
Normal
Abnorma
Normal
lAbnorma
Normal
l
Normal
Normal
Abnorma
lAbnorma
l
11
Jill’s Test Sample
Blood Pressure
Blood chemistry: Cholesterol
Blood chemistry: HDL
Blood chemistry: LDL
Blood chemistry:
Total cholesterol to HDL ratio
Red blood cell count
Hemoglobin
Hematocrit
White blood cell count
Urinalysis
Pap Smear
Normal Test Result
Less than 120/80
Less than 200mg/ml
Over 60 mg/dl
100-129 mg/dl
5:1 to 3.5:1
Patient’s Lab Result
119/78
149 mg/ml
66 mg/ml
109 mg/dl
3:1
4.8-5.4 million/cc
12.0 – 14.5 g/dL
36.0 – 44.5 %
4,300-10,800/cc
No glucose or ketones
Small nuclei and dark,
solid chromatin; intact
microfilaments in the
cytoplasm
4.7 million/cc
11.7
34.2
5,000/cc
No glucose or ketones
Small nuclei and dark
solid chromatin
Normal or
Abnormal?
Normal
Normal
Normal
Normal
Abnorma
lAbnorma
Abnorma
lAbromarl
lNormal
Normal
Normal
To interpret cholesterol test results, please see this Mayo Clinic web site:
http://www.mayoclinic.org/tests-procedures/cholesterol-test/details/results/rsc20169555
To interpret blood count test results, please see this Mayo Clinic web site:
http://www.mayoclinic.com/health/complete-blood-count/MY00476/DSECTION=results
Lab Report Question 7. Which lab result values for Jack were abnormal?
A. Blood pressure and blood chemistry (lipid profile)
B. Urinalysis
C. Red Blood Cell Count and White Blood Cell Count
D. PSA
E. A, B, and D
E
Lab Report Question 8. Which lab result values for Jill were abnormal?
A. Blood pressure and blood chemistry (lipid profile)
B. Urinalysis
C. Red Blood Cell Count, Hemoglobin, and Hematocrit
D. White Blood Cell Count
E. PAP Smear
C
Lab Report Question 9. Which abnormal vital signs and abnormal medical lab tests would
indicate that a person has hypertension and is at risk for coronary heart disease?
Blood pressure that is over 120/80 and blood
© Northampton Community College
12
chemistry testing would identify is a person has
hypertension and at risk for coronary heart disease.
© Northampton Community College
13
Contemporary Biology Online
Lab 9: Digestion and Nutrition, Diet, and Maintaining a Healthy Weight
Learning Objectives:
• Understand the organs, structure and functions of the digestive system
• Understand the relationship among Body Mass Index (BMI), Basal Metabolic Rate (BMR), a
healthy weight, and risk factors for disease.
• Understand food labels and know how to interpret them to plan a meal.
• Learn the number of Calories found in one gram of fat, protein, and carbohydrate.
• Be able to calculate calories per serving and % calories from a food label.
• Use nutrition information to plan a meal.
• Compare and contrast different food pyramids.
The Digestive System: The digestive system in humans contains several organs that perform
the four functions of digestion: physical digestion (e.g., chewing) which breaks the ingested
food into smaller fragments; chemical digestion in the stomach and small intestine, where
enzymes hydrolyze food molecules into their subunits; absorption of nutrients from the small
intestine into the blood, and excretion, where indigestible remains are expelled.
1. See pages 255 – 257 in your textbook to learn the digestive organs.
2. View the following animation: https://www.youtube.com/watch?v=-Zyk0H1HmjA
Lab Report Question 1. Match the letter of the function to the digestive system component.
Term
Letter Answer
H
G
j
D
I
E
B
A
f
c
Liver
Digestion System Component
A. Where carbohydrate digestion begins (amylase
cleaves starch)
Pharynx
B. Stores, churns food; begins protein digestion
Esophagus
C. Reabsorbs water, ions, vitamins; stores waste
Stomach
D. Completes digestion; primary site of nutrient
absorption
Appendix
E. Emulsifies fats in the small intestine
Bile
F. Regulates blood glucose levels; releases digestive
enzymes
Small
intestine
G. Where swallowing begins
In the mouth
H. Breaks down and build molecules; produces bile
Pancreas
I. Contains cells of the immune system
Large
intestine
J. Transports food from the pharynx to the stomach
1
Why Is a Healthy Weight Important? Maintaining a healthy weight can help you prevent and control
many diseases and conditions associated with being overweight. Factors that contribute to a person’s
weight include environment, family history and genetics, metabolism (the way your body changes food and
oxygen into energy), and behavior or habits.
Energy balance is important for maintaining a healthy weight. The amount of energy or calories you get
from food and drinks (energy IN) is balanced with the energy your body uses for things like breathing,
digesting, and being physically active (energy OUT).
Weight gain = More energy IN than OUT over time; Weight
loss = More energy OUT than IN over time.
To maintain a healthy weight, your energy IN and OUT don’t have to balance exactly every day: it’s the
balance over time that helps maintain healthy weight.
Assessing your weight and health risk involves using three key measures:
1. Body mass index (BMI)
2. Waist circumference
3. Risk factors for diseases and conditions associated with obesity
Part 1: Body Mass Index (BMI), Weight and Disease Risk
BMI is a measure of body fat that is calculated from your height and weight. The higher your
BMI, the higher your risk for heart disease, high blood pressure, type 2 diabetes, gallstones,
breathing problems, and certain cancers. See page 261of your textbook for a BMI chart. You
can calculate your BMI using the following formula:
BMI = weight (in kilograms) divided by height squared (in meters).
Lab Activity: Jack and Jill have decided to manage their weight.
Jack is 5’10” tall and weighs 205 pounds.
Jill is 5’2″ tall and weighs 115 pounds.
1. Go to the National Heart, Lung, and Blood Institutes’ BMI calculator web page:
https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm
2. Enter Jack’s height and weight into the calculator and click on “Compute BMI.” Enter the
value into the appropriate space in the data table below. Repeat for Jill
3. Using the chart below, determine Jack and Jill’s Weight Category.
BMI
Weight Category
Below 18.5
Underweight
18.5-24.9
Normal
25.0-29.9
Overweight
30.0 and Above
Obese
Jack’s BMI = 29.4
Jack’s Weight Category = Overweight
Jill’s BMI = 21
Jill’s Weight Category = Normal
2
Part 2: Waist Circumference
Waist circumference helps screen for health risks associated with obesity. Fat around the waist
(rather than at the hips), indicates a higher risk for heart disease and type 2 diabetes. This risk
goes up with a waist size that is >35 inches for women or >40 inches for men. The table below
indicates whether BMI combined with waist circumference increases the risk for developing
obesity-associated diseases or conditions.
(To correctly measure your own waist, stand and place a tape measure around your middle, just
above your hipbones. Breathe out, then measure your waist.)
Lab Activity: Convert Jack and Jill’s waist sizes to cm and use them along with their BMIs to identify their
disease risk in Table 2.
Jack’s waist size = 47 inches.
Jill’s waist size = 29 inches
Jack’s waist size in cm = (Waist size inches x 2.54) = 119 cm
Jill’s waist size in cm = (Waist size inches x 2.54) = 73 cm
Table 2. DISEASE RISK: Classification of weight by BMI, waist circumference, and associated
disease risks for type 2 diabetes, hypertension, and cardiovascular disease.
BMI
Waist Circumference
Men 102 cm
Women > 88 cm
Contemporary
Biology Online Learning Objectives
•
•
•
•
•
•
Learn the types of sensory receptors important for homeostasis
Identify the different parts of the human eye and understand their functions
Explain blind spot, farsightedness, nearsightedness, and astigmatism
Perform an online colorblindness test
Learn about the science of some optical illusions
Test a hypothesis, analyze data and draw conclusions about visual reaction time
Materials from the Student – Internet access, yardstick or tape measure,
textbook; 3–6 volunteer test subjects for the visual reaction time experiment
Introduction: The sensory nervous system receives different stimuli and sends
nerve impulses to the central nervous system (the brain and spinal cord), where
various parts of the brain will be alerted and will determine how to respond to
maintain stable homeostasis. Our ability to touch, hear, taste, smell and see is
determined by sensory receptors connected to a network of neurons communicating
with our brain via the spinal cord. Scientists use different approaches to learn how
receptors and neurons communicate with each other and what causes certain
sensory problems, such as chronic pain, hearing loss, blindness and other
conditions.
Five senses: Sight, hearing, smell, taste, touch
Types of sensory receptors that detect the internal body environment:
•
•
•
•
•
•
Chemoreceptors detect chemicals in the environment or the blood (e.g., CO2
levels).
Mechanoreceptors respond to touch and pressure in the skin, hair, and inner
ear.
Nociceptors detect pain, usually near the surface of tissues.
Photoreceptors in the eye are the rods and cones. Rods detect dim light (black
and white) and are located on the periphery of the retina; cones detect color
and are located in the center of the retina.
Proprioceptors detect body position and allow detailed skeletal movements.
Thermoreceptors detect cold and heat.
This lab exercise focuses on the functional anatomy and physiology of the eye.
Anatomy of the Human Eye
Read page 289 in Chapter 11.21 of your textbook for more background facts, and
visit this interactive tutorial about vision:
Figure 1: Human Eye
In Your Blackboard Lab Report
Lab Report Question 1. Complete the following matching activity to reinforce your
knowledge about the eye. (Other eye structures could be on a future lab quiz so
review the basic eye anatomy.)
Eye
Answer
Description of the Anatomical Structures and
Functions
1. Cornea
C
2. Lens
E
3. Iris
D
4. Retina
A
5. Blind Spot
B
A. Light sensitive layer of cells (with rods and cones);
connected to the brain via optic nerve; known as the eye’s
“camera film”
B. Where no photoreceptors (no rods and no cones) are
found; where the optic nerve exits the retina; an image on this
location is not seen
C. Is the first to bend the incoming light into the eyes; is a
clear outer covering that protects the lens and iris; can get
infected or scratched
D. Circular muscle that controls how much light enters the
eye; its pigmentation is responsible for “eye color”
E. Flexible structure that can change its shape to focus on
objects near and far; clouding of this structure results in
cataract formation
Common Vision Problems
•
A nearsighted person cannot clearly see objects that are located far away.
•
A farsighted person cannot see objects that are very close to their eyes.
•
A person with astigmatism has blurry vision because of an abnormally
curved cornea. Astigmatism often occurs together with nearsightedness or
farsightedness.
In Your Blackboard Lab Report
Lab Report Question 2. What causes these visual conditions? Analyze the
following diagrams below to complete this online activity in Blackboard.
Eye Condition
1. Astigmatism
2. Farsightedness
3. Nearsightedness
4. Normal vision
Answer
D
A
B
C
Explanation
A. Light is focused behind the retina
B. Light is focused in front of the retina
C. Light is focused directly on the retina
D. Light is focused on multiple places on the retina
Thus corrective lenses are required to adjust specific vision problems.
To Learn More: Learn about Lasik Surgery
http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/SurgeryandLif
eSupport/L ASIK/default.htm
• Lab Activity: Visual Tests and Experiments – Record your results in this
handout
•
Take the Online Color Blind Test
Dr. Shinobu Ishihara developed a color perception test in 1917 to identify redgreen color blindness, which is the most common type of color blindness. Lack of
or dysfunctional cone photoreceptors are some causes of color blindness. The
genes for the red and green visual pigments (photoreceptors) are on the X
chromosome.
•
•
•
Go to http://www.eyes-and-vision.com/color-blindness-test.html
Record the numbers you can see inside each circle in the data table below.
Check your answers with the website.
IMPORTANT! If you cannot see the numbers, then you may be colorblind;
however, consulting a vision care professional is recommended since this
online activity is not diagnostic. Note that the results can be affected by the
colors shown by the computer monitor and the lighting conditions.
A
Number
Observed
•
25
B
6
C
45
D
8
E
56
F
29
Visual Acuity (Ability to Focus on Sharp Details)
Proper vision includes the eyes, brain, and the visual pathways working in
collaboration.
The Dutch eye doctor Dr. Herman Snellen created an eye chart in the early 1860s
to measure visual acuity, or the ability to focus on sharp details. The Snellen
fraction 20/20 is used to define “normal” vision but not “perfect” vision.
Generally, as the bottom number of the Snellen fraction increases, the worse the
person’s visual acuity. A fraction of 20/40 indicates that someone can read at 20 feet
away what a person with normal vision could read at 40 feet away.
Thus, nearsighted people without corrective lenses will have to stand closer to the
Snellen chart. Sometimes one eye has a better visual acuity than the other.
Memorization of the letters on the Snellen chart may occur with repeated use of
the same Snellen chart. Use a chart with different letters or numbers if a person
repeats the test too often.
Instructions
•
First, complete the 4 online visual screening tests provided by
Sterling Optical https://devlynoptical.com/online-vision-test/
•
Record your observations and results in the data table provided
below.
Name of the Visual Test
Record your online vision results
DISTANCE
READING
ASTIGMATISM
EYE HEALTH
(RETINAL OR
MACULAR
DAMAGE)
I took the test 3 times and the results weren’t sent to me, but on the screen it said
that my reading power is +2.00. Left eye was at 87.5% excellent and 75% very
good.
• Astigmatism: Blurred vision may occur if the cornea or lens is shaped
irregularly, which prevents light from focusing properly on the retina. As a result,
vision becomes blurred at any
distance. Astigmatism is
a very common vision condition. Most people have
some degree of astigmatism.
Optometrists use an astigmatism chart to
determine if the condition is present.
No astigmatism is present if all the radiating lines
appear equally dark and distinct if the refracting
surface is not distorted.
Instructions:
Astigmatism is present (to some degree) if some of the lines are blurred and
appear less dark than others.
• Focus on the center of the radiating image with each eye separately
and note the appearance of the radiating lines. Did you detect
astigmatism?
• Record your results (yes or no): Right eye: yes
Left eye: no
DATA ANALYSIS: Let’s review what you learned about the blind spot,
colorblindness, visual acuity (Snellen fractions), and astigmatism. Please answer the
following questions based on your results and the background information provided.
Write in complete, coherent sentences.
Lab Report Question 3. Did you detect any form of colorblindness? And what 2
challenges do you think color-blind persons face in everyday life?
I did not detect any colorblindness in my exams. I think that 2 challenges
colorblind people face in everyday life might be driving because of the stop lights and
another one is not being able to cordinate colofl outfits
Lab Report Question 4. Do you have normal vision (20/20) in each eye based on
the online eye exam? Compare your Snellen fraction to the normal standard of
20/20. What conclusions can you make about your results? Use this website to
answer to determine your fraction. http://www.allaboutvision.com/eye-test/snellenchart.pdf
I dont have 20/20 vision, I believe I have 20/80.
Lab Report Question 5. Which vision results did you find were unexpected or most
interesting? Explain your reasons.
I have a stigma in my right eye, which I already was aware of because of my eye
exams.
• Science of optical illusions
Read the BBC news article that provides fun, optical illusions and describes how
scientist Beau Lotto is learning how our brain process multisensory information.
Go to http://www.bbc.co.uk/news/magazine-11553099 to see some examples.
Be sure to watch the video clip “How the brain thinks a rubber glove is a real hand,”
which is an optical illusion that demonstrates neuroplasticity.
Lab Report Question 6.
a. Which optical illusion example did you like the best and why?
I like the Jungle Scene illusion becasue you cant see the animal in the black and white
portion but you can clearly see it in the colored version.
To Learn More
Many more optical illusions are available at http://www.michaelbach.de/ot/
Test your ability to see afterimages:
http://www.exploratorium.edu/exhibits/bird_in_a_cage/bird_in_a_cage.html
•
Lab Activity: Online reaction time experiment
The human body
communicates and responds to the environment using 3 types of neurons: sensory
neurons, association neurons (interneurons), and motor neurons as described on
textbook pages 288 – 289. To conclude this lab exercise on how the eye works and
communicates with the nervous system, you will perform an experiment to test visual
reaction time. A reaction time is based on
a voluntary
response, whereas a
reflex is an involuntary
response. A directional
flow of information in a
reaction response
starts with the stimulus
(e.g., pin prick of the
finger) by the sensory
receptors, which
communicate
with the sensory nerves that connect to the central nervous system (CNS which is the
spinal cord and brain); after which the brain sends commands to the motor neurons
which control the effector responses, such as the voluntary muscles (e.g., stepping
on the car brake after you see a yellow or red traffic light signal).
The faster a person responds to a visual cue (e.g., color change of a traffic light) the
lower the reaction time will be in units of time (e.g., seconds). However, there are
multiple factors influencing why a person might have different reaction times to the
same visual cue on any given day. For example, some contributing factors to slower
reactions time might be distractions (e.g., texting; loud noises), fatigue, time of day
(e.g., working morning or night shifts), medications, neural disorders, vision
problems, and more.
Purpose: To determine a person’s reaction time by clicking a mouse button in
response to a visual cue using an online reaction test website
Question: What factors influence visual reaction time? Select an independent
variable (a condition or factor) that you think will influence a person’s reaction time
to a random visual signal. For example, choose to test the effect of one of the
following independent variables:
•
•
•
•
•
•
Age (older individuals vs. younger individuals)
Time of day (morning vs. night)
Distraction (no distractions vs. distractions present such as loud background
sounds)
Alertness
Fatigue
Other factor that you find relevant
Instructions
• Preform the Online reaction time test . Go to
http://getyourwebsitehere.com/jswb/rttest01.html
(a screen shot is provided for you on the next page so you know what to
expect).
• Follow the directions for the online reaction time test in the text box provided.
IMPORTANT:
Copy these online results into your lab handout to calculate the group
If you could repeat this visual reaction time experiment to get more accurate results, briefly explain
what you would change and briefly explain why.
If I had to repeat this experiment again I would focus more on the big button then the green
light. By that, I was starring at the green light and having a late reaction to clicking the button.
What kinds of information can you learn about a person, or a group of people, by testing their visual
reaction time?
You can learn if they’re fit to drive and maybe play sports without reacting slow
and getting injured.
Test Number
Reaction Time
1
0.403
2
0.373
3
0.387
4
0.346
5
0.412
AVG
0.3842
Exercise 8: Vital Signs and Medical Lab Tests
Contemporary Biology Online
Learning Objectives
•
•
•
•
•
Learn how to measure basic vital signs – pulse rate, breathing rate, blood pressure
Explain the 2 numbers used to measure blood pressure – systolic vs. diastolic pressure
Understand high blood pressure (hypertension) and its causes
Learn some of the routine screening tests used to evaluate overall health: blood test, urinalysis
Analyze clinical lab test results against normal standards – Pap smear, PSA test, blood
cholesterol profile, and blood cell count (red blood cells, white blood cells)
Materials from the Student — Computer, internet access, watch (or clock), textbook
INTRODUCTION
The human body is incredible! Every second, hundreds of trillions of reactions occur within trillions of
cells, allowing tissues, organs, and organ systems to maintain life. This narrow range of acceptable
parameters (temperature, pH, heart rate, etc.), is constantly kept in balance, or homeostasis.
To maintain our health and well-being, we need to be sure that we are getting proper nutrition and
rest, exercising and maintaining a healthy lifestyle and weight, and doing our best to prevent disease.
When we are well, we pay little attention to the inner workings of our bodies. When we are ill or in
pain, we are made acutely aware of our internal operating system and its many components. One
should visit the doctor for routine yearly check-ups and when we are ill or injured, to ensure our
continued good health.
PART 1: UPON ARRIVAL AT THE DOCTOR’S OFFICE: You’ll need to fill out some paperwork. In
addition to your name, date of birth, and address, you may be required to show your insurance card
and photographic identification (driver’s license, etc), if you have them, before being seen. You’ll need
to list contacts and who can share your records, as well as signing a HIPA (Health Information
Protection Act of 2005) form to keep your personal information private.
Your role is of utmost importance: communication. Tell the doctor your concerns, answer lifestyle
questions honestly, and be sure to ask any questions you may have before leaving.
Be prepared to answer the following questions asked by your doctor and health care provider:
• Why have you come in?
• If not for a routine check-up, what is your history of present illness? Do you have a cold, a
fever, injury, or pain?
• What is your past medical history? Describe in detail any prior surgeries, vaccinations, major
infections, allergies (immune system reactions to food or mediation, from mild rashes to
critical breathing problems), and diseases (abnormal condition from external sources, such as
bacterial infections, smoking, etc.) or disorders (abnormal condition from internal origins, such
as a genetics, etc) you already have.
© Northampton Community College
1
•
How much do you know about your family medical history? Are your parents or grandparents
affected by heart disease, diabetes, cancer, high cholesterol, or inherited illnesses? You will be
asked these questions to ascertain if you are a candidate for genetic testing.
To Learn More: For more information about HIPA, please see http://www.hhs.gov/ocr/privacy/
PART 2: VITAL SIGNS
A nurse or technician will provide the preliminary examination by collecting signs (objective; can be
measured or observed; deformity or open wound) and symptoms (complaints; subjective; pain or
nausea). Vital signs are ways to measure our current physical state. If our vital signs are out of
normal limits, they indicate that something may be wrong. **Keep in mind, however, that some
individuals’ vital signs are normally a bit different from what we consider to be typical! **
➢ Respiration: We need to breathe in oxygen and give off carbon dioxide continuously. Each time
we breathe in and out is one respiration. The average respiratory rate (respirations per minute) is
about 12 to 20 breaths per minute. Respiration rate (breathing rate; measured in
breaths per minute) is determined by observing
the chest rise (during inspiration) and the chest
falling (expiration). Oxygen gas (O2) is inhaled
and carbon dioxide gas (CO2) is exhaled. The gas
exchange occurs at the interface between the
capillary network (circulatory system) and the alveoli
sacs (respiratory system); thus, blood transports the
gases around the body. See diagram insert to review.
Respiration rate can change with age, level of activity, lung
capacity, dehydration, altitude, drug overdose, and overall lung health.
➢ Body temperature: Every day, chemical reactions inside us keep us alive (collectively referred to
as metabolism) and generate heat. The measure of this heat is our body temperature, usually
98.6oF or 37oC. A fever is an elevated temperature unrelated to environment or exertion, and it
can indicate that an infection is present. Normal human body temperature depends upon the place
in the body at which the measurement is made, the time of day and level of activity of the body.
➢ Pulse: When your heart pumps blood through your arteries, we can feel it as a wave, or pulse,
which is triggered by the heart’s pacemaker called the sinoatrial node. The heart of the average
resting person beats about 60 to 100 times each minute. A pulse rate is measured in heart
beats per minute. Some fit individuals may have a slower resting pulse rate, while stress,
exertion, and caffeine make the heart beat faster. We can feel our pulse at superficial arteries in
our neck (carotid), wrist (radial), inner elbow (brachial), and groin (femoral). Pulse rate changes
with age, body weight, physical training, emotion, activity level, body temperature and overall
heart health.
© Northampton Community College
2
➢ Blood pressure (BP): The force of the blood in the arteries is measure as blood pressure. We
measure blood pressure with a manual or digital apparatus called a sphygmomanometer. To use
a manual sphygmomanometer, a rubber balloon within a flat fabric sleeve (called a “cuff”) is
wrapped around the upper arm and inflated. As the cuff deflates, we measure when the pulse
returns to the squeezed arm, and then when we can no longer detect it. These two numbers are
recorded as a fraction. Ideally, 120/80 mmHg (millimeters of mercury) is considered normal, but
there is dramatic variation in ‘normal’ blood pressure. BP reading can vary by age, time of day,
level of physical activity, and existing chronic or short-term illnesses.
o The top number, the systolic pressure, records the force of the heart actually beating.
The maximum systolic pressure occurs when the heart contracts (“squeezes”) blood
out into the arteries.
o The bottom number, the diastolic pressure, is the left-over pressure while the heart is
resting between beats and filling with blood.
Everyone’s blood pressure varies throughout the day. Hypertension, known as the ‘silent killer,’ is
chronic high blood pressure, which may lead to heart disease and stroke if untreated.
Low blood pressure, called hypotension, may cause one to feel dizzy or black out.
To Learn More about symptoms and causes of low blood pressure (hypotension) go to
http://www.mayoclinic.com/health/low-blood-pressure/DS00590/DSECTION=causes
© Northampton Community College
3
PART 3: PHYSICAL EXAMINATION
After recording your vital signs, the nurse or doctor may also perform the following:
•
•
•
•
Observation: Note skin color, apparent discomfort, body positioning, eye appearance, etc.
Auscultation: A stethoscope is used to listen to the sounds of your lungs, heart, and bowels.
Percussion: Sometimes tapping on your torso will help discover a problem. If normal, air-filled
tissue has been displaced by fluid or by trapped air, percussion will generate a sound different
than expected.
Palpation: The neck, abdomen, and any painful limbs are palpated (felt) for any sore spots,
deformity, or swelling.
PART 4: COMMON FOLLOW-UP RECOMMENDATIONS: Your doctor may suggest routine blood
tests for blood chemistry, cholesterol, and total blood counts; imaging for a painful body region (X-ray,
MRI, CT scan, etc.); and annual check-ups, which for females includes a PAP test for cervical cancer,
and a PSI test to screen for prostate cancer in males. Other follow-ups may include dental cleaning
and check-up, urine sample analysis, bone density test for osteoporosis, and/or calculating body mass
index (BMI) to measure body fat and obesity.
Lab Activity – Record Your Vital Signs
Respiratory Rate: One inhalation (breathing in) and exhalation (breathing out) equals one
respiration. Please review “Essential Biological Process 25A: Breathing” and read The Mechanics of
Breathing on pages 262 – 263 in your textbook. To measure your respiratory rate,
1. Breathe normally at rest, but not after any exercise.
2. Count the number of complete respirations (breathing in and out) over one minute period, or
count each complete respiration for 15 seconds and multiply the number by 4.
If you have a mirror, sit or stand in front of the mirror. Watch the number of times your chest rises and
falls. Or, place your hand on top of your chest to count the number of complete respirations.
3. Repeat two more times. Then calculate your average respiration rate by adding the 3 results
and divide by 3.
4. Record your data in Table 1.
Table 1. My Respiration Rate at Rest
Vital Sign
Respiration rate
Normal Ranges Reading #1
12- 20 breaths
per minute
© Northampton Community College
25
Reading #2
23
Reading #3
20
Average
22
4
Pulse Rate: The pulse rate is the number of heartbeats per minute. To measure
your pulse rate,
1. Turn your left hand palm-side up. Then place the first two fingers of your
right hand along the outer edge of your left wrist just below where your
wrist and thumb meet.
2. Slide your fingers toward the center of your wrist. You should feel the
pulse between the wrist bone and the tendon.
3. Press down with our fingers until you feel your pulse. Do not press too hard, or you will not be
able to feel the pulsation. Feel free to move your fingers until the pulse is
easiest to feel.
4. Continue to feel your pulse for a one minute, or count each pulsation for
15 seconds and multiply the number by 4. Concentrate on whether the
beats are evenly spaced, or whether they are erratic, with missed beats,
extra beats, or beats that are too close together.
Table 2. My Pulse Rate at Rest
Vital Sign
Pulse rate
Normal Ranges Reading #1
60 – 100 beats
per minute
80
Reading #2
92
Reading #3
94
Average
88
*Recommendation: Visit your doctor annually to monitor your blood pressure and your other health concerns.
In Your Blackboard Report:
Lab Report Question 1. At rest, we hope your averages for both vital signs were within the normal
ranges listed in Table 1. Why is it important to take multiple readings, and then calculate the average,
and not rely on one reading of each vital sign?
It is importatnt to take multiple readings as your breathing changes. My first reading I believe I was concentrating
too much on the breathing and was breathing faster. But the other readings I was able to relaxe more to capture my
natural breathing.
Lab Report Question 2. Would increasing your physical activity from sitting to brisk walking (or
jogging) increase or decrease your respiration rate and pulse rate? Why? Briefly explain your
reasoning. Phsycial activity would increase your respiration and pulse rate. As your heart rate increase so does
your pulse and your breathing as lungs are working more. You begin breathing faster and harder to make sure
oxygen reaches the blood and carbon releases.
© Northampton Community College
5
HINT: Visit “pumping action” for clues:
http://science.nationalgeographic.com/science/health-and-human-body/human-body/heart-article/
© Northampton Community College
6
Lab Activity – Measuring Blood Pressure
Instructions: Watch the following animations:
In Your Blackboard Lab Report: Please answer the questions below:
Lab Report Question 3. Choose from (A. right; B. left; or C. central) to fill in the sentence below
The human heart has four heart chambers (see diagram below). Deoxygenated blood enters the
first chamber of the heart, called the left atrium. The sinoatrial node, the heart’s “pacemaker,”
is also located in the right atrium and sends out an electrical signal to make the heart beat
rhythmically.
Lab Report Question 4. Choose from (A. ventricle; or B. atrium) to fill in the sentence below
Both upper atrium chambers contract together and empty (push) blood into the lower ventricle.
Lab Report Question 5. Choose from (A. ventricle; B. atrium; C. Systolic or D. Diastolic) to fill in the
sentence below
The ventricle contract together to push blood into the arteries away into different parts of the body.
This heart contraction is the source of the blood pressure reading known as the diastolic pressure.
© Northampton Community College
7
What is Hypertension?
According to the National Heart, Lung and Blood Institute, 1 in 3 persons living in the United
States has high blood pressure (also known as hypertension). One of the most dangerous
aspects of hypertension is that you may not know that you have it – this is why it is called the silent
killer. In fact, nearly one-third of people who have high blood pressure don’t know it.
The only way to know if your blood pressure is high is through regular checkups. This is especially
important if you have a close relative who has high blood pressure.
Some symptoms of high blood pressure include severe headache, fatigue or confusion, vision
problems, chest pain, difficulty breathing, irregular heartbeat, blood in the urine, and pounding in your
chest, neck, or ears. If you have any of these symptoms, see a doctor immediately; you could be
having a hypertensive crisis that could lead to a heart attack or stroke.
If left untreated, hypertension can lead to stroke, heart failure, coronary heart disease, kidney failure,
and eye problems.
Table 3. The American Heart Association’s description of the range of blood pressures considered
normal and those that indicate increasing levels of hypertension.
Blood Pressure
Category
Normal
Systolic
mm Hg (upper #)
Diastolic
mm Hg (lower #)
less than 120
and
less than 80
Prehypertension
120 – 139
or
80 – 89
High Blood Pressure
(Hypertension) Stage 1
140 – 159
or
90 – 99
High Blood Pressure
(Hypertension) Stage 2
160 or higher
or
100 or higher
Hypertensive Crisis
(Emergency care needed)
Higher than 180
or
Higher than 110
© Northampton Community College
8
How are Cholesterol and Other Lipids (Fats) Involved in Coronary Heart Disease?
Instructions: Go to the following website:
http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=hdlldl
Watch “Cholesterol Score” and “Cholesterol and Coronary Heart Disease” from the menu options,
then answer the matching questions below.
Lab Report Question 6. Complete the following matching questions after watching the animations.
Descriptions
Answer
Choices
1. The “bad” cholesterol; this lipoprotein deposits
cholesterol in the artery walls causing
atherosclerotic plaque formation
F
A. Cholesterol
2. The “good” cholesterol; this lipoprotein removes
cholesterol from the blood stream and artery
walls
D
B. Triglycerides
3. Are stored in fat cells and used as energy, but
excessively high levels are associated with
other health conditions (e.g., being overweight)
A
C. Coronary heart disease
4. HDL + LDL + Triglyceride = Number
E
D. High density lipoprotein
(HDL)
5. The process that causes arteries to stiffen,
harden; may lead to a heart attack
C
E. Total Cholesterol
Score
6. Narrowing of the arteries of the heart reducing
proper flow of oxygen rich blood
G
F. Low density lipoprotein
(LDL)
7. Used to form cell membranes, aid in digestion,
make hormones
B
G. Atherosclerosis
© Northampton Community College
9
What are the Signs of a Heart Attack?
Coronary heart disease (CHD)—the most common type of heart disease—is the #1 killer of both men
and women in the United States. Coronary Heart Disease (CHD) occurs when plaque builds up on
the inner walls of your
coronary arteries. These
arteries carry oxygen-rich
blood to your heart. When
plaque builds up in the
arteries, the condition is
called atherosclerosis.
Plaque is made up of fat,
cholesterol, calcium, and
other substances found in
the blood. Over time, plaque
can harden or rupture
(break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich
blood to the heart. This can cause chest pain or discomfort called angina. If the plaque ruptures, a
blood clot can form on its surface. A large blood clot can mostly or completely block blood flow
through a coronary artery. This is the most common cause of a heart attack. Over time, ruptured
plaque also hardens and narrows the coronary arteries.
In the United States, 1 in 4 women die from heart disease. Learn about differences in heart attack
symptoms between men and women at this web site. http://www.webmd.com/heartdisease/news/20050218/men-vs-women-confusion-over-heart-symptoms
COMPREHENSION CHECK: According to the web site, what are the most common symptoms
characterizing men’s heart attacks and women’s heart attacks?
a. Men have cold sweat; women have shortness of breath.
b. Men have lightheadedness; women have cold sweat.
c. Men have chest pain; women have indigestion.
d. Men have indigestion; women have chest pain.
To Learn More about heart disease in women and to educate others, visit
http://www.womenshealth.gov/heart-health-stroke/signs-of-a-heart-attack/,
© Northampton Community College
10
Medical Laboratory Panels
In addition to measuring your vital signs, healthcare providers may request specific laboratory tests to
detect, treat, or monitor certain health conditions or diseases. For example, urine, blood, bodily
substances and other tissues may be tested for certain chemical profiles or cellular observations.
Normal values vary from person to person and are presented as normal ranges of expected values.
Laboratory test results can be affected by many factors, such as intake of specific foods, medications,
gender, age, race, medical history, general health and even variations among laboratories or their
techniques. You will often be required to fast at least 8 hours before having a blood test.
Blood chemistry panel: This panel examines the complete blood count (CBC); the lipid profile, and
factors in your blood that may indicate kidney or liver problems.
Lipid profile: Lipids do not dissolve in water but dissolve in other substances. The lipid profile
evaluates the risk for cardiovascular disease associated with atherosclerosis (arterial plaque or
hardening of the arteries). The following lipid components are measured:
•
•
•
•
•
Total Cholesterol: measures all of the cholesterol in all the lipoprotein particles
Triglycerides: another form of fat; these lipid molecules reform from digested fats
HDL Cholesterol: called “good cholesterol” because it removes excess cholesterol and
carries it to the liver for removal; higher the HDL, the better
LDL Cholesterol: called “bad cholesterol” because it deposits excess cholesterol in walls
of blood vessels, which can contribute to atherosclerosis
Total Cholesterol/HDL Ratio: A higher ratio indicates a higher risk of heart disease; a
lower ratio indicates a lower risk
Goals of healthy cholesterol management are to
➢ Increase HDL (“good”) cholesterol levels
➢ Decrease LDL (“bad”) cholesterol
➢ Do regular exercise, eat low-fat foods and take medications
Complete blood count (CBC) is used to detect a
wide range of disorders, including anemia, infection
and leukemia. The following blood components are
analyzed: oxygen-transporting red blood cells
(RBCs), infection-fighting white blood cells (WBCs);
the amount of the oxygen transport protein called
hemoglobin; blood-clotting platelets, and the
hematocrit (ratio of red blood cells to fluid blood
plasma).
Urine test can check for color, pH, clarity, odor,
microscopic sediments, and among other substances. High glucose sugar levels in urine can
indicate diabetes or damaged kidneys.
Pap Smear in females can detect early signs of cervical cancer by sampling and analyzing cells
from the cervix, which is located between the base of the uterus and the vaginal opening (birth
© Northampton Community College
10
canal). The Pap test can identify potential infections and abnormal cervical cells (see textbook
pages 281 – 284 for an explanation of the female reproductive system).
Prostate Specific Antigen (PSA) test in males detects the PSA protein, which produced by the
prostate gland and can be detected in blood. The prostate is gland found at the base of the
bladder (see page 280 in your textbook). Higher PSA levels may indicate an inflamed or enlarged
prostate or the presence of prostate cancer. However, some prostate cancer cases may have no
elevated PSA, so careful consultation with the doctor is critical to making important health
decisions.
PSA – Prostate Specific Test (Men only)
Pap Smear Test (Women only)
Bladder
Lab Activity: Jack and Jill have gone to the doctor for their annual check-up.
Jack is 47 years old; he is 5’10” tall and weighs 205 pounds.
Jill is s 47 years old; she is 5’2″ tall and weighs 115 pounds.
Some results from their check-up and lab tests are shown below. Based on the Normal Test Results
values listed in the chart below, which patient’s lab results are normal, and which are abnormal?
Jack’s Test Sample
Blood Pressure
Blood chemistry: Cholesterol
Blood chemistry: HDL
Blood chemistry: LDL
Blood chemistry:
Total cholesterol to HDL ratio
Red blood cell count
White blood cell count
Urinalysis
Normal Test Result
Less than 120/80
Less than 200mg/ml
Over 60 mg/dl
100-129 mg/dl
5:1 to 3.5:1
Patient’s Lab Result
138/83
249 mg/ml
57 mg/ml
174 mg/dl
4.4:1
4.8-5.4 million/cc
4300-10,800/cc
No glucose or ketones
Prostate Specific Antigen
4 ng/ml
5.0 million/cc
5,000/cc
Some glucose and
ketones
7 ng/ml
© Northampton Community College
Normal or
Abnormal?
Normal
Abnorma
Normal
lAbnorma
Normal
l
Normal
Normal
Abnorma
lAbnorma
l
11
Jill’s Test Sample
Blood Pressure
Blood chemistry: Cholesterol
Blood chemistry: HDL
Blood chemistry: LDL
Blood chemistry:
Total cholesterol to HDL ratio
Red blood cell count
Hemoglobin
Hematocrit
White blood cell count
Urinalysis
Pap Smear
Normal Test Result
Less than 120/80
Less than 200mg/ml
Over 60 mg/dl
100-129 mg/dl
5:1 to 3.5:1
Patient’s Lab Result
119/78
149 mg/ml
66 mg/ml
109 mg/dl
3:1
4.8-5.4 million/cc
12.0 – 14.5 g/dL
36.0 – 44.5 %
4,300-10,800/cc
No glucose or ketones
Small nuclei and dark,
solid chromatin; intact
microfilaments in the
cytoplasm
4.7 million/cc
11.7
34.2
5,000/cc
No glucose or ketones
Small nuclei and dark
solid chromatin
Normal or
Abnormal?
Normal
Normal
Normal
Normal
Abnorma
lAbnorma
Abnorma
lAbromarl
lNormal
Normal
Normal
To interpret cholesterol test results, please see this Mayo Clinic web site:
http://www.mayoclinic.org/tests-procedures/cholesterol-test/details/results/rsc20169555
To interpret blood count test results, please see this Mayo Clinic web site:
http://www.mayoclinic.com/health/complete-blood-count/MY00476/DSECTION=results
Lab Report Question 7. Which lab result values for Jack were abnormal?
A. Blood pressure and blood chemistry (lipid profile)
B. Urinalysis
C. Red Blood Cell Count and White Blood Cell Count
D. PSA
E. A, B, and D
E
Lab Report Question 8. Which lab result values for Jill were abnormal?
A. Blood pressure and blood chemistry (lipid profile)
B. Urinalysis
C. Red Blood Cell Count, Hemoglobin, and Hematocrit
D. White Blood Cell Count
E. PAP Smear
C
Lab Report Question 9. Which abnormal vital signs and abnormal medical lab tests would
indicate that a person has hypertension and is at risk for coronary heart disease?
Blood pressure that is over 120/80 and blood
© Northampton Community College
12
chemistry testing would identify is a person has
hypertension and at risk for coronary heart disease.
© Northampton Community College
13
Contemporary Biology Online
Lab 9: Digestion and Nutrition, Diet, and Maintaining a Healthy Weight
Learning Objectives:
• Understand the organs, structure and functions of the digestive system
• Understand the relationship among Body Mass Index (BMI), Basal Metabolic Rate (BMR), a
healthy weight, and risk factors for disease.
• Understand food labels and know how to interpret them to plan a meal.
• Learn the number of Calories found in one gram of fat, protein, and carbohydrate.
• Be able to calculate calories per serving and % calories from a food label.
• Use nutrition information to plan a meal.
• Compare and contrast different food pyramids.
The Digestive System: The digestive system in humans contains several organs that perform
the four functions of digestion: physical digestion (e.g., chewing) which breaks the ingested
food into smaller fragments; chemical digestion in the stomach and small intestine, where
enzymes hydrolyze food molecules into their subunits; absorption of nutrients from the small
intestine into the blood, and excretion, where indigestible remains are expelled.
1. See pages 255 – 257 in your textbook to learn the digestive organs.
2. View the following animation: https://www.youtube.com/watch?v=-Zyk0H1HmjA
Lab Report Question 1. Match the letter of the function to the digestive system component.
Term
Letter Answer
H
G
j
D
I
E
B
A
f
c
Liver
Digestion System Component
A. Where carbohydrate digestion begins (amylase
cleaves starch)
Pharynx
B. Stores, churns food; begins protein digestion
Esophagus
C. Reabsorbs water, ions, vitamins; stores waste
Stomach
D. Completes digestion; primary site of nutrient
absorption
Appendix
E. Emulsifies fats in the small intestine
Bile
F. Regulates blood glucose levels; releases digestive
enzymes
Small
intestine
G. Where swallowing begins
In the mouth
H. Breaks down and build molecules; produces bile
Pancreas
I. Contains cells of the immune system
Large
intestine
J. Transports food from the pharynx to the stomach
1
Why Is a Healthy Weight Important? Maintaining a healthy weight can help you prevent and control
many diseases and conditions associated with being overweight. Factors that contribute to a person’s
weight include environment, family history and genetics, metabolism (the way your body changes food and
oxygen into energy), and behavior or habits.
Energy balance is important for maintaining a healthy weight. The amount of energy or calories you get
from food and drinks (energy IN) is balanced with the energy your body uses for things like breathing,
digesting, and being physically active (energy OUT).
Weight gain = More energy IN than OUT over time; Weight
loss = More energy OUT than IN over time.
To maintain a healthy weight, your energy IN and OUT don’t have to balance exactly every day: it’s the
balance over time that helps maintain healthy weight.
Assessing your weight and health risk involves using three key measures:
1. Body mass index (BMI)
2. Waist circumference
3. Risk factors for diseases and conditions associated with obesity
Part 1: Body Mass Index (BMI), Weight and Disease Risk
BMI is a measure of body fat that is calculated from your height and weight. The higher your
BMI, the higher your risk for heart disease, high blood pressure, type 2 diabetes, gallstones,
breathing problems, and certain cancers. See page 261of your textbook for a BMI chart. You
can calculate your BMI using the following formula:
BMI = weight (in kilograms) divided by height squared (in meters).
Lab Activity: Jack and Jill have decided to manage their weight.
Jack is 5’10” tall and weighs 205 pounds.
Jill is 5’2″ tall and weighs 115 pounds.
1. Go to the National Heart, Lung, and Blood Institutes’ BMI calculator web page:
https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm
2. Enter Jack’s height and weight into the calculator and click on “Compute BMI.” Enter the
value into the appropriate space in the data table below. Repeat for Jill
3. Using the chart below, determine Jack and Jill’s Weight Category.
BMI
Weight Category
Below 18.5
Underweight
18.5-24.9
Normal
25.0-29.9
Overweight
30.0 and Above
Obese
Jack’s BMI = 29.4
Jack’s Weight Category = Overweight
Jill’s BMI = 21
Jill’s Weight Category = Normal
2
Part 2: Waist Circumference
Waist circumference helps screen for health risks associated with obesity. Fat around the waist
(rather than at the hips), indicates a higher risk for heart disease and type 2 diabetes. This risk
goes up with a waist size that is >35 inches for women or >40 inches for men. The table below
indicates whether BMI combined with waist circumference increases the risk for developing
obesity-associated diseases or conditions.
(To correctly measure your own waist, stand and place a tape measure around your middle, just
above your hipbones. Breathe out, then measure your waist.)
Lab Activity: Convert Jack and Jill’s waist sizes to cm and use them along with their BMIs to identify their
disease risk in Table 2.
Jack’s waist size = 47 inches.
Jill’s waist size = 29 inches
Jack’s waist size in cm = (Waist size inches x 2.54) = 119 cm
Jill’s waist size in cm = (Waist size inches x 2.54) = 73 cm
Table 2. DISEASE RISK: Classification of weight by BMI, waist circumference, and associated
disease risks for type 2 diabetes, hypertension, and cardiovascular disease.
BMI
Waist Circumference
Men 102 cm
Women > 88 cm
