Deck 21: Muscle Blood Flow and Cardiac Output During Exercise; the Coronary Circulation and Ischemic Heart Disease

Question 1

A 60-year-old man has been told by his doctor that he has angina caused by myocardial ischemia. Which of the following treatments would be beneficial for him?

A)Angiotensin converting enzyme inhibition
B)Isometric exercise
C)Chelation therapy such as EDTA
D)Beta receptor stimulation
E)Increased dietary calcium

Answer 1

A

Question 2

Which of the following increases the risk of adverse cardiac events?

A)Decreased blood levels of LDL
B)Decreased blood levels of HDL
C)Female gender
D)Moderate hypotension
E)Decreased blood triglycerides

Answer 2

B

Question 3

The majority of venous blood flow leaves the heart muscle through which of the following?

A)Anterior cardiac veins
B)Azygos vein
C)Bronchial veins
D)Coronary sinus
E)Thebesian veins

Answer 3

D

Question 4

Which is usually the most important controller of coronary blood flow?

A)Adenosine
B)Bradykinin
C)Prostaglandins
D)Carbon dioxide
E)Potassium ions

Question 5

Which of the following is normally associated with an increased tendency for the heart to fibrillate following a myocardial infarction?

A)Current of injury from ischemic cardiac muscle
B)Decreased extracellular potassium concentration
C)Decreased sympathetic stimulation
D)Increased extracellular sodium concentration
E)Decreased cardiac volume

Question 6

A 60-year-old man experienced an ischemia-induced myocardial infarction and died from ventricular fibrillation. What factor was most likely to increase the tendency of the heart to fibrillate after the infarction?

A)Low potassium concentration in the heart extracellular fluid
B)A decrease in ventricular diameter
C)Increased sympathetic stimulation of the heart
D)Low adenosine concentration
E)Decreased parasympathetic stimulation of the heart

Question 7

A healthy 40-year-old man has been exercising maximally for 15 minutes. Which of the following conditions is likely to be present?

A)Arteriolar resistance in the gastrointestinal bed is increased by 200%
B)Cerebral blood flow is decreased to 50% of normal
C)Heart rate is unchanged
D)Cardiac output is increased 5%
E)Right atrial pressure is increased to 10 mmHg

Question 8

Which of the following normally causes vasodilation of skeletal muscle arterioles during exercise?

A)Decreased plasma osmolality
B)Decreased plasma nitric oxide concentration
C)Increased plasma potassium concentration
D)Decreased plasma adenosine concentration
E)Increased plasma histamine concentration

Question 9

Which of the following vascular beds experiences the most vasoconstriction in a person near the end of a 5-mile run?

A)Cerebral
B)Coronary
C)Exercising muscle
D)Intestinal
E)Skin

Question 10

At the onset of exercise, the mass sympathetic nervous system strongly discharges. Which of the following would you expect to occur?

A)Increased sympathetic impulses to the heart
B)Decreased coronary blood flow
C)Decreased cerebral blood flow
D)Reversed stress relaxation
E)Dilation

Question 11

During mild exertion a 70-year-old man has an ischemia-induced myocardial infarction and dies from ventricular fibrillation. In this patient, which factor was most likely to increase the tendency of the heart to fibrillate after the infarction?

A)Increased parasympathetic stimulation of the heart
B)A decrease in ventricular diameter
C)Low potassium concentration in the heart extracellular fluid
D)A more negative ventricular membrane potential
E)Current of injury from the damaged area

Question 12

Which of the following will elevate the plateau of the cardiac output curve?

A)Surgically opening the thoracic cage
B)Placing a patient on a mechanical ventilator
C)Cardiac tamponade
D)Increasing parasympathetic stimulation of the heart
E)Increasing sympathetic stimulation of the heart