Question 1

Which of the following best describes the role of the hypothalamus in the endocrine system?

Accepted Answer

It regulates the pituitary gland by releasing hormones that control anterior and posterior pituitary function.

Question 2

A patient suffers a blockage in the left anterior descending (LAD) artery. Which region of the heart is most at risk for ischemia?

Accepted Answer

Interventricular septum and anterior walls of both ventricles

Question 3

Which statement about cardiac muscle is TRUE when compared to skeletal muscle?

Accepted Answer

Cardiac muscle contraction lasts longer due to the presence of a plateau phase in the action potential.

Question 4

During the cardiac cycle, which event occurs immediately after the mitral valve closes?

Accepted Answer

Isovolumetric contraction of the left ventricle

Question 5

Which formula correctly represents cardiac output ($CO$) in terms of heart rate ($HR$) and stroke volume ($SV$)?

Accepted Answer

$CO = HR 	imes SV$

Question 6

A patient has a defect in the tricuspid valve. Which of the following is most likely to occur?

Accepted Answer

Backflow of blood from the right ventricle to the right atrium during systole

Question 7

Which phase of the pacemaker cell action potential is responsible for the rapid influx of $Ca^{2+}$ ions?

Accepted Answer

Phase 2: Depolarization

Question 8

Which of the following best explains why the heart muscle does NOT regenerate after injury?

Accepted Answer

Cardiac muscle cells have limited mitotic ability and are replaced by fibrous tissue.

Question 9

Which structure is responsible for delaying the electrical impulse between the atria and ventricles, allowing for proper ventricular filling?

Accepted Answer

Atrioventricular (AV) node

Question 10

Which of the following correctly describes the pathway of blood through the right side of the heart?

Accepted Answer

Superior vena cava → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary arteries

Question 11

Which of the following is a function of the coronary sinus?

Accepted Answer

It collects deoxygenated blood from the cardiac veins and empties into the right atrium.

Question 12

Which part of the ECG corresponds to ventricular depolarization?

Accepted Answer

QRS complex

Question 13

A patient has a mutation that prevents the formation of gap junctions in cardiac muscle. What is the most likely consequence?

Accepted Answer

Electrical impulses will not spread efficiently, leading to uncoordinated contractions.

Question 14

Which of the following best describes the effect of sympathetic stimulation on the heart?

Accepted Answer

Increases heart rate and force of contraction

Question 15

Which equation correctly represents the relationship between blood flow ($F$), pressure difference ($\Delta P$), and resistance ($R$)?

Accepted Answer

$F = \Delta P / R$

Question 16

Which of the following is TRUE regarding the systemic and pulmonary circuits?

Accepted Answer

Pulmonary circuit is short and low pressure, systemic circuit is long and high pressure

Question 17

Which of the following is the correct sequence of excitation in the intrinsic cardiac conduction system?

Accepted Answer

SA node → AV node → Bundle of His → Bundle branches → Purkinje fibers

Question 18

Which of the following is a benefit of the longer action potential and contraction in cardiac muscle compared to skeletal muscle?

Accepted Answer

It ensures efficient ejection of blood and prevents tetanic contractions.

Question 19

Which of the following best explains the function of the chordae tendineae?

Accepted Answer

They prevent AV valve cusps from everting into the atria during ventricular contraction.

Endocrine System and Heart: Anatomy & Physiology Study Notes

Study Guide - Practice Questions