Q: Which equation best represents the negative feedback loop that controls excessive sympathetic output?

$$\text{Increased sympathetic activity} \rightarrow \text{Release of ACh at sweat glands} \rightarrow \text{Activation of muscarinic receptors} \rightarrow \text{Inhibition of further sympathetic activity}$$

Question 1

Which of the following best describes the main function of the autonomic nervous system (ANS)?

Accepted Answer

To regulate involuntary processes such as heart rate, blood pressure, and digestion.

Question 2

A patient is experiencing increased heart rate and dilated pupils after a car accident. Which division of the ANS is primarily responsible for these responses?

Accepted Answer

Sympathetic nervous system

Question 3

Which of the following is TRUE regarding the organization of the sympathetic nervous system?

Accepted Answer

Preganglionic neurons originate in the thoracic and upper lumbar spinal cord.

Question 4

Which neurotransmitter is most frequently released by postganglionic sympathetic neurons at their target cells?

Accepted Answer

Norepinephrine (noradrenaline)

Question 5

A drug blocks beta-2 adrenergic receptors. Which physiological effect would most likely be observed?

Accepted Answer

Constriction of bronchioles, leading to reduced airflow

Question 6

Which of the following best explains the difference between somatic and autonomic motor neurons?

Accepted Answer

Somatic motor neurons innervate skeletal muscle and cause voluntary contractions, while autonomic motor neurons innervate cardiac muscle, smooth muscle, and glands to produce involuntary actions.

Question 7

Which of the following is a correct pathway for a visceral reflex arc in the ANS?

Accepted Answer

Sensory signals from the viscera are sent to the CNS, which then sends motor impulses to autonomic ganglia and target organs.

Question 8

Which of the following statements about the parasympathetic nervous system is CORRECT?

Accepted Answer

Preganglionic cell bodies are located in the nuclei of several cranial nerves and the sacral region of the spinal cord.

Question 9

Which of the following best describes the role of acetylcholine (ACh) in the sympathetic nervous system?

Accepted Answer

ACh is released by preganglionic sympathetic neurons at synapses with postganglionic neurons.

Question 10

A patient is given a medication that stimulates alpha-1 adrenergic receptors. Which effect would most likely be observed?

Accepted Answer

Constriction of blood vessels, leading to increased blood pressure

Question 11

Which equation best represents the negative feedback loop that controls excessive sympathetic output?

Accepted Answer

$$	ext{Increased sympathetic activity} ightarrow 	ext{Release of ACh at sweat glands} ightarrow 	ext{Activation of muscarinic receptors} ightarrow 	ext{Inhibition of further sympathetic activity}$$

Question 12

Which of the following is a direct effect of norepinephrine binding to beta-1 receptors on cardiac muscle cells?

Accepted Answer

Opening of ion channels that increases both the rate and force of contraction

Question 13

Which of the following best describes the anatomical location of the sympathetic chain ganglia?

Accepted Answer

Parallel to the vertebral column, running from the cervical to the sacral region

Question 14

A patient with asthma is prescribed a beta-2 agonist. What is the expected physiological effect?

Accepted Answer

Dilation of bronchioles, increasing airflow to the lungs

Question 15

Which of the following correctly matches the receptor type with its location?

Accepted Answer

Beta-2 receptors: found in the plasma membranes of smooth muscle cells in the airways

Question 16

Which of the following is a correct statement about the effects of the sympathetic nervous system on metabolic rate?

Accepted Answer

It binds to beta-2 receptors on adipocytes and triggers the breakdown of lipids, releasing fatty acids into the bloodstream.

Question 17

Which of the following equations best represents the effect of norepinephrine on blood pressure when it binds to alpha-1 receptors?

Accepted Answer

$$	ext{Norepinephrine} + 	ext{alpha-1 receptor} ightarrow 	ext{Vasoconstriction} ightarrow 	ext{Increased blood pressure}$$

Question 18

Which of the following is a correct description of the role of the adrenal medulla in the sympathetic nervous system?

Accepted Answer

It acts as a modified sympathetic ganglion, releasing norepinephrine and epinephrine into the blood.

Question 19

A patient is experiencing difficulty urinating during a stressful situation. Which receptor and neurotransmitter interaction is most likely responsible?

Accepted Answer

Norepinephrine binding to beta-3 receptors on urinary sphincters

Autonomic Nervous System: Structure, Function, and Physiology

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