Question 1

Which of the following best describes the intrinsic activity of the heart?

Accepted Answer

The heart can generate rhythmic activity without nervous input.

Question 2

A patient is given a drug that selectively activates cardiac $$\$$beta_1$$-adrenergic receptors. Which of the following effects would you expect?

Accepted Answer

Increased heart rate, increased ventricular contractility, and increased AV nodal conduction.

Question 3

Which neurotransmitter is released by both sympathetic and parasympathetic preganglionic neurons at the autonomic ganglion?

Accepted Answer

Acetylcholine (ACh)

Question 4

A student claims that parasympathetic activity should increase heart rate because ACh is released by both autonomic divisions at their ganglia. What is the error in this reasoning?

Accepted Answer

The effect of ACh depends on the receptor and target tissue, not just its release.

Question 5

Which receptor is activated by norepinephrine (NE) released from sympathetic postganglionic neurons at the heart?

Accepted Answer

$$\$$beta_1$$-adrenergic receptor

Question 6

Which of the following best defines 'dromotropy'?

Accepted Answer

The speed of electrical conduction through cardiac tissue, especially AV nodal conduction.

Question 7

A hypothetical drug blocks M$$_2$$ receptors in the heart. What would be the expected effect on parasympathetic regulation of heart rate?

Accepted Answer

Parasympathetic activity would be unable to slow the heart rate.

Question 8

Which of the following is a correct pairing of autonomic division, neurotransmitter, and receptor at the cardiac target?

Accepted Answer

Sympathetic, norepinephrine, $$\$$beta_1$$-adrenergic receptor

Question 9

A classmate experiences increased vagal activity. Which of the following best explains the resulting changes in heart function?

Accepted Answer

Increased vagal (parasympathetic) activity releases ACh at the heart, activating M$$_2$$ receptors, which decreases heart rate and slows AV nodal conduction.

Question 10

Which of the following statements is TRUE regarding the effects of sympathetic stimulation on the heart?

Accepted Answer

It increases heart rate, ventricular contractile force, and AV nodal conduction.

Question 11

A researcher administers a drug that slows AV nodal conduction but does not affect SA node pacing. Which functional effect has changed, and which has not necessarily changed?

Accepted Answer

Dromotropy has changed; chronotropy has not necessarily changed.

Question 12

Which of the following best describes the effect of parasympathetic stimulation on ventricular contractile force?

Accepted Answer

It has a relatively small direct effect on ventricular contractile force.

Question 13

Which of the following terms is correctly matched with its physiological variable?

Accepted Answer

Chronotropy: heart rate

Question 14

A patient with increased sympathetic activity is described as having 'the heart beats faster.' Why is this description incomplete?

Accepted Answer

Sympathetic activity also increases ventricular contractile force and AV nodal conduction, not just heart rate.

Question 15

Which of the following statements best explains why a neurotransmitter can have different effects in different tissues?

Accepted Answer

The effect depends on the receptor type and the target tissue where the neurotransmitter is released.

Question 16

Which of the following is a negative chronotropic effect?

Accepted Answer

Decreased heart rate

Question 17

Which pathway correctly describes the autonomic motor route to the heart?

Accepted Answer

CNS → preganglionic neuron → autonomic ganglion → postganglionic neuron → heart

Question 18

Which of the following is a common misconception about autonomic control of the heart?

Accepted Answer

The brain tells the heart to beat every time.

Question 19

Which receptor is activated by acetylcholine released from parasympathetic postganglionic neurons at the cardiac target?

Accepted Answer

Muscarinic M$$_2$$ receptor

Question 20

Which of the following best describes the effect of sympathetic stimulation on AV nodal conduction?

Accepted Answer

It increases AV nodal conduction (positive dromotropic effect).

Autonomic Control of the Heart: Cardiac Physiology Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard