Question 1

Which of the following best describes the difference between the somatic motor and autonomic divisions of the efferent nervous system?

Accepted Answer

Somatic motor neurons control skeletal muscle and are mostly voluntary, while autonomic neurons control smooth muscle, cardiac muscle, glands, and some adipose tissue and are mostly involuntary.

Question 2

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

Accepted Answer

Acetylcholine

Question 3

A patient is given a drug that blocks muscarinic receptors. Which of the following effects would you expect?

Accepted Answer

Increased heart rate due to inhibition of parasympathetic activity

Question 4

Which of the following is true regarding the adrenal medulla?

Accepted Answer

It is a modified sympathetic ganglion that secretes epinephrine into the blood.

Question 5

Which equation best represents the effect of $$\$$beta_1$$ adrenergic receptor activation on second messenger systems?

Accepted Answer

$$	ext{Increase in cAMP}$$

Question 6

Which of the following statements about antagonistic control in the autonomic nervous system is correct?

Accepted Answer

Most internal organs are under antagonistic control, where one branch is excitatory and the other is inhibitory.

Question 7

A patient is exposed to a beta-blocker. Which of the following physiological effects would you expect?

Accepted Answer

Decreased heart rate due to inhibition of sympathetic $$\$$beta_1$$ receptors

Question 8

Which of the following best describes the neurotransmitter and receptor at the neuromuscular junction?

Accepted Answer

Acetylcholine acting on nicotinic receptors

Question 9

Which of the following is a property of somatic motor neurons?

Accepted Answer

They originate in the CNS and are myelinated, very long, and always excitatory.

Question 10

Which of the following is a correct sequence for neurotransmitter release at a sympathetic neuroeffector junction?

Accepted Answer

Action potential arrives → voltage-gated Ca$$^{2+}$$ channels open → Ca$$^{2+}$$ entry triggers exocytosis → NE binds to adrenergic receptor

Question 11

Which of the following best explains why the effect of a neurotransmitter in the autonomic nervous system depends on the receptor subtype present on the target tissue?

Accepted Answer

The receptor subtype determines the intracellular signaling pathway and thus the physiological response.

Question 12

Which of the following is a characteristic of the parasympathetic division?

Accepted Answer

Ganglia located on or near target organs

Question 13

Which of the following is a correct statement about the vagus nerve?

Accepted Answer

It contains about 75% of all parasympathetic fibers.

Question 14

Which of the following best describes the function of varicosities in autonomic neurons?

Accepted Answer

They release neurotransmitter over the surface of target cells.

Question 15

Which of the following is true regarding the removal of norepinephrine at the sympathetic neuroeffector junction?

Accepted Answer

Norepinephrine is metabolized by monoamine oxidase (MAO) in the mitochondria of the varicosity.

Question 16

Which of the following is a property of nicotinic acetylcholine receptors at the neuromuscular junction?

Accepted Answer

They are chemically-gated channels with two binding sites for ACh.

Question 17

A patient is given atropine, a muscarinic antagonist. Which of the following effects would you expect?

Accepted Answer

Increased heart rate due to inhibition of parasympathetic activity

Question 18

Which of the following best describes the structure of a somatic motor pathway?

Accepted Answer

Consists of one neuron originating in the CNS and innervating a single skeletal muscle fiber

Question 19

Which of the following is a correct statement about the effect of acetylcholinesterase (AChE) inhibitors?

Accepted Answer

They decrease the breakdown of acetylcholine, leading to prolonged activation of cholinergic receptors.

Efferent Division: Autonomic and Somatic Motor Control – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards