Q: Which equation best represents the mechanism by which alpha-2 adrenergic receptors inhibit effector cell activity?

$$\text{Activation of alpha-2 receptor} \rightarrow \text{Decrease in intracellular cAMP}$$

Question 1

Which of the following best describes the organization of the sympathetic division of the autonomic nervous system?

Accepted Answer

Preganglionic fibers are short and ganglia are located close to the spinal cord, except for the adrenal medulla.

Question 2

A patient is experiencing increased heart rate, dilated pupils, and reduced sensitivity to pain after a traumatic event. Which division of the autonomic nervous system is most likely activated, and what neurotransmitters are primarily responsible?

Accepted Answer

Sympathetic division; epinephrine and norepinephrine

Question 3

Which of the following is TRUE regarding the neurotransmitter release in the adrenal medulla during sympathetic activation?

Accepted Answer

Preganglionic fibers release acetylcholine, stimulating endocrine cells to release epinephrine and norepinephrine into the bloodstream.

Question 4

Which receptor type is responsible for vasoconstriction of peripheral blood vessels and closure of digestive and urinary sphincters during sympathetic activation?

Accepted Answer

Alpha-1 adrenergic receptors

Question 5

A drug that selectively blocks beta-2 adrenergic receptors would most likely cause which of the following effects?

Accepted Answer

Constriction of respiratory passageways, making breathing more difficult

Question 6

Which of the following best explains the functional significance of dual innervation in the heart?

Accepted Answer

It enables precise regulation of heart rate by balancing sympathetic (NE) and parasympathetic (ACh) activity.

Question 7

Which equation best represents the mechanism by which alpha-2 adrenergic receptors inhibit effector cell activity?

Accepted Answer

$$	ext{Activation of alpha-2 receptor} ightarrow 	ext{Decrease in intracellular cAMP}$$

Question 8

Which of the following is a characteristic of the parasympathetic division's organization?

Accepted Answer

Preganglionic fibers are long and synapse in terminal or intramural ganglia near or within the target organ.

Question 9

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

Accepted Answer

Constriction of pupils and increased digestive gland secretion

Question 10

Which of the following best describes autonomic tone?

Accepted Answer

It is the continuous, baseline level of activity in autonomic motor neurons, allowing fine-tuned control of organ function.

Question 11

Which of the following is TRUE regarding the neurotransmitter and receptor types in the parasympathetic division?

Accepted Answer

Both preganglionic and postganglionic fibers release acetylcholine, which binds to nicotinic and muscarinic receptors, respectively.

Question 12

Which of the following is a major effect of parasympathetic activation?

Accepted Answer

Constriction of pupils and stimulation of urination and defecation

Question 13

Which equation best represents the mechanism of nicotinic receptor activation in the parasympathetic division?

Accepted Answer

$$	ext{ACh binds to nicotinic receptor} ightarrow 	ext{Opening of chemically gated Na^+ channels}$$

Question 14

Which of the following best describes a visceral reflex?

Accepted Answer

An autonomic reflex initiated in the viscera that produces a motor response in organs like blood vessels, heart, and digestive tract.

Question 15

Which of the following scenarios illustrates the importance of autonomic tone in blood vessel regulation?

Accepted Answer

Background sympathetic tone keeps vessels partially constricted, allowing diameter and blood flow to be finely tuned by adjusting norepinephrine release.

Question 16

Which of the following is a correct match between receptor type and its primary response?

Accepted Answer

Beta-2 adrenergic receptor: relaxation of smooth muscle in bronchi

Question 17

A patient with a spinal cord injury at the thoracolumbar region is likely to have impaired function in which division of the autonomic nervous system?

Accepted Answer

Sympathetic division (thoracolumbar)

Question 18

Which equation best represents the effect of beta-3 adrenergic receptor activation in adipocytes?

Accepted Answer

$$	ext{Activation of beta-3 receptor} ightarrow 	ext{Lipolysis (breakdown of stored fat)}$$

Question 19

Which of the following best describes the effect of sympathetic activation on energy reserves?

Accepted Answer

Mobilization of glycogen and lipids for ATP production

Question 20

Which of the following is a distinguishing feature of the parasympathetic division compared to the sympathetic division?

Accepted Answer

Parasympathetic preganglionic fibers are long and postganglionic fibers are short, both releasing acetylcholine.

The Autonomic Nervous System: Structure, Function, and Regulation

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