PLTW Heart Disease Exam Questions with Answers
What do you think would happen in the heart if the AV node could no longer do its job? Explain how this would affect the contraction of the heart and the movement of blood. - Answer-If the AV node could no longer do its job, then the ventricles woul...
What do you think would happen in the heart if the AV node could no longer do its job?
Explain how this would affect the contraction of the heart and the movement of blood. -
Answer-If the AV node could no longer do its job, then the ventricles would not have the
electrical charge needed to contract, and the blood would not be able to move through
the rest of the body.
In the space below, explain what an EKG can tell a physician about the heart of a
specific patient. - Answer-The EKG can tell irregular heartbeat, irregular speed of
contractions, angina (chest pain that can indicate tissue damage), or even tissue death
(myocardial infarction, also known as a heart attack).
Describe how the structure of the aorta relates to its function in the heart. - Answer-The
aorta is a tube that transports the oxidized blood to the rest of the body. It needs to be
bigger because it must push all the blood through the rest of the body.
Propose reasons why the heart rates of different people are different when exposed to
the same stressor or to the same physical activity, even though their resting heart rates
are the same - Answer-People's heart rate may be different due to the way the brain
may react to the stressor or physical activity. It may also be different due to the physical
health of the individual, and rather they are healthy or not. These factors may all cause
differences even if it is the same stressor.
How do LDL and HDL differ structurally and functionally? - Answer-Functionally - LDL
takes the cholesterol to the cells, while HDL removes excess cholesterol from the
bloodstream and takes it back to the liver
At the time of her cardiac work-up, Anna Garcia had an average resting heart rate of
98bpm. What does this say about her overall heart health? - Answer-It says overall that
her heart is not at a healthy rate. It means that it requires more from the heart to pump
blood to the rest of her body. This may overwork the heart, and cause other health
problems. Overall, her heart health is lacking and may become worse.
What structural differences did you notice between arteries and veins? Relate these
differences to the function of the vessels. - Answer-Arteries and arterioles have thicker
walls than veins, respectively. The increased amount of smooth muscle that is found in
arteries gives them extra strength and elasticity to deal with the surges of blood from the
heart.
Veins have valves within them to prevent backflow of blood. Veins have wider inner
diameters, too, that means that they can hold more blood. Since it would be impossible
, anyway to get all the blood back to the heart as quickly as it left the heart, the veins
have to have more blood in them than the arteries.
Anna's autopsy report noted mitral valve prolapse. This means that the mitral valve
does not close properly. Explain why this could be a problem. - Answer-The valves are
supposed to help the blood move in the right direction. If the valves do not work properly
then the blood will not move in the right direction, and the body will not get the oxidized
blood it needs.
Which chamber of the heart do you think is the most muscular? Explain your reasoning.
- Answer-The left ventricle because it is in charge pumping blood through the aorta.
This job is what gives the rest of the blood to the body, so it needs the most muscle to
pump the blood through the rest of the body.
2. A growing fetus has a vessel, the ductus arteriosus, in the heart that connects the
pulmonary artery with the aorta and conducts blood directly from the right ventricle to
the aorta. Why do you think this vessel closes soon after birth? - Answer-The vessel
closes to have full separation between oxygenated blood and deoxygenated blood. The
right atrium and ventricle are supposed to transport the deoxygenated blood, and the
left atrium and ventricle are supposed to transport the oxygenated blood and then
transfer to the aorta, where the blood will go to the rest of the body.
3. In most of the body, the arteries carry oxygenated blood and the veins carry
deoxygenated blood. The exception to this pattern is the heart. Explain how and why
specific arteries and veins of the heart are different from the pattern seen in the rest of
the body. - Answer-In the exception of the heart, pulmonary veins transport oxygenated
blood from the lungs to the heart. This is different from the rest of the body because the
veins are supposed to carry deoxygenated blood.
Describe the mechanisms in place to prevent the blood from flowing in the wrong
direction through the heart. - Answer-Valves prevent the blood from flowing in the wrong
direction. There are valves on the connecting arteries, and keep the blood moving in the
right direction.
Explain how cholesterol plays an important role in at least two different human body
systems. - Answer-Cholesterol plays an important role in the endocrine system and the
digestive system. Cholesterol is used in the synthesis of bile acids, which break down
food in the digestive system. Cholesterol is also the precursor of pregnenolone, the
precursor of all steroid hormones. So without cholesterol, the steroid hormones would
not be made
Explain what happens to tissues, such as the heart, or the brain, if oxygenated blood is
not delivered in a timely manner. - Answer-Tissue starts to die if oxygenated blood is
not delivered. If the tissue dies, then the organs will fail. If the organs fail then the body
will not be able to operate and die. This is especially in the brain, brain tissues rely on
oxygen, and without, significant brain damage can occur.
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