Chapter 20 Reading Questions
The Heart

"Queen of Hearts"                  "Get to the heart of the matter"
"Wearing your heart on your sleeve"              "Have a heart!"
"Your dog has heart worms"                      "Change of heart"
What an organ, even February 14th celebrates the heart.

Part 1: The Anatomy of the Heart
    A. Location, layers, and chambers
    B. Valves and defects
    C. Coronary circulation

1. Identify the location and borders of the heart. Do you have your heart
in the right place? Let's examine the anatomical position of the heart.

a. The heart is located in the space between the lungs called the
    _____________________________________.
b. This is in the _______________________________ cavity
c. Most of the heart lies to the _______________ of the sternum.
d. The pointed end is called the ________ and lies between
    ribs ______________ and __________________.
e. The blunt end of the heart is called the __________.
f. The left border of the heart is the _______________________.
g. The right border of the heart is the ______________________.
h. The inferior surface of the heart rests on the _______________.

2. Distinguish between the layers of the pericardium and the layers of the
heart wall by listing these layers from superficial to deep.

1. ___________________________________
2. ___________________________________
3. ___________________________________
4. ___________________________________
5. ___________________________________
6. ___________________________________

3. Identify the structure of cardiac muscle. Make a fist, this is the size of
your heart. Slightly open and close your fist tightly, this is the action of
cardiac muscle. A verse for Valentine's Day may go like this:

My
muscular pump is in a slump over you!

Draw and label cardiac muscle cells as you remember them from last semester.

nucleus
intercalated discs

The layer of the heart containing cardiac muscle is called the ______________.

3. Identify the parts of the heart by labeling the following drawing.

student drawing Donna Arpoika-Riley

4. Describe the chambers of the heart.

a. Name the area of the heart from which all blood vessels enter or emerge. _______________________________
b. List the three blood vessels that enter the right atrium.

1. ______________________________
2. ______________________________
3. ______________________________

c. Which atrium receives blood filled with carbon dioxide from the tissues? _____
d. Name the blood vessels that empty into the left atrium.
    ________________________________________________
    (Note: these veins carry oxygenated blood.)
e. Which atria receives blood from the lungs? ____________
f. Name the blood vessel that emerges from the right ventricle.
    ________________________________________________
    (Note: these arteries contain deoxygenated blood.)
g. Name the blood vessel that emerges from the left ventricle.
    __________________________________________________
h. The major pumping burden of the heart is the function of the
    __________________________________________________

5. Did you ever wonder why the heart is red? This is inaccurate as the heart is
really two separate pumps. Name the correct colors for the two sides of the heart.                  _______________________________________________
The right side is called the ______________________ circulation and
the left side is called the ________________________ circulation.

6. The endocardium lines the blood vessels and chambers of the heart . This
fibrous tissue also forms the four valves that prevent the backflow of blood.

A. Two cusp-shaped valves separate the atria and ventricles,
on the right side is the __________________________ valve,
on the left side is the ____________________ valve also known
as the mitral valve. These valves are open during most of the cardiac
cycle. Upon closing, the sound they produce is ____________.
When would you expect these valves to close?
__________________________________________________
Name the strings that prevent the AV valves from turning inside out.
_________________________________________________

They say roses are red and violets are blue,
but my cuspid valves won't turn inside out for you!

My heart sings Lubb, dupp when your stethoscope is near,
Placed over the apex, you'll hear it quite clear!

7. Discuss the purpose of the foramen ovale and the ductus arteriosum in the fetal heart. ________________________________________________________________
________________________________________________________________

If these fail to close then the congenital defects are called the
_____________________________ and _______________________________
Why does the skin appear blue (cyanotic)?
________________________________________________________________

8. Describe mitral valve stenosis.
________________________________________________________________
________________________________________________________________

9. Identify the main coronary blood vessels and the heart chambers they supply.
The heart is a vital organ and has four times more supply of blood than does skeletal
muscle. These coronary vessels are a redundant supply to the four heart chambers.

right coronary artery

anterior marginal artery ____________________________________
posterior interventricular artery ______________________________

left coronary artery

posterior circumflex artery _________________________________
anterior interventricular artery _______________________________

10. How are ischemia and angina pectoris related?
    ________________________________________________________

    How are atherosclerosis and a myocardial infarction related?
    _________________________________________________________

    List four factors that contribute to coronary artery disease.
    _________________________________________________________

Focus question
Trace a drop of blood from the superior vena cava to the
posterior interventricular artery.

Part 2: The Conduction System of the Heart
    A. Conduction pathway
    B. Electrocardiogram

11. Explain how the heart contracts independently.
________________________________________________________________
________________________________________________________________
________________________________________________________________

12. Explain the action potentials that are initiated by the SA node.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________

13. List in order, the pathway over the heart's conduction system.

1. ______________________________________
2. ______________________________________
3. ______________________________________
4. ______________________________________

14. Describe the meaning of the deflection waves on an EKG and the electrical events that are represented.

P wave __________________________________________________________
________________________________________________________________

QRS wave ______________________________________________________
________________________________________________________________

T wave __________________________________________________________
________________________________________________________________

P-R interval ______________________________________________________
________________________________________________________________

S-T segment ______________________________________________________
________________________________________________________________

15. List the circumstances that would warrant a resting EKG on a person.

1. ______________________________________________
2. ______________________________________________
3. ______________________________________________
4. ______________________________________________
5. ______________________________________________

Here is a homemade poem to help you review the heart's conduction system.
If the English department of the college sees this, I will probably be fired for
illiteracy. The following is "for your heart only".

Once upon an action potential
    the SA node said "I'm existential,"
I'll let sodium in naturally
    but potassium ions must leave.
Now calcium, my excitement can prolong
    then repolarize to where they all belong.
Next, send this message to the atrial wall,
    and over again these ions do fall
Sweeping through membranes where they should not be
    causing atrial contraction in unity.
The AV node serves as a bridge,
    sending impulses to the interventricular ridge.
The purkinje fibers are the next to rise
    causing the ventricles to depolarize.