2020 - Heart Physiology 2

Inotropic agents affect:

• contractility

• depolarization

• heart rate

• stroke volume

Which of the following is a chronotropic agent that decreases heart rate?

• glucagon

• norepinephrine

• acetylcholine

• epinephrine

What largely determines preload?

• stroke volume

• end-diastolic volume (EDV)

• end-systolic volume (ESV)

• afterload

Which hormone decreases cardiac output by decreasing blood volume and preload?

• atrial natriuretic peptide (ANP)

• aldosterone

• antidiuretic hormone (ADH)

• norepinephrine

What two factors determine the pressure gradient that drives blood flow?

• blood vessel radius and blood vessel length

• cardiac output and peripheral resistance

• diastolic pressure and systolic pressure

• heart rate and stroke volume

Which of the following will decrease peripheral resistance?

• increase in vessel obstructions

• increase in vessel radius

• increase in vessel length

• increase in blood viscosity

Which of the following does NOT assist the return of venous blood to the heart?

• respiratory pump

• venous valves

• skeletal muscle pump

• elastic fibers

Which nervous system promotes increased peripheral resistance and vasoconstriction of systemic arterioles?

• sympathetic nervous system

• sensory nervous system

• parasympathetic nervous system

• somatic nervous system

What is detected by a baroreceptor?

• blood oxygen content

• blood pH

• blood pressure

• blood sugar

Central chemoreceptors detect a decrease in pH in interstitial fluids in the brain. What is the response of the medulla to maintain delivery of oxygen to cells?

• increased parasympathetic activity, vasoconstriction and a rise in blood pressure

• increased sympathetic activity, vasoconstriction and a rise in blood pressure

• decreased sympathetic activity, vasodilation and a decrease in blood pressure

• increase in parasympathetic activity, vasodilation and a decrease in blood pressure