Question 1

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

Accepted Answer

Somatic motor division uses one neuron and targets skeletal muscle, while autonomic motor division uses two neurons and targets smooth/cardiac muscle and glands.

Question 2

A patient is given a drug that selectively blocks muscarinic receptors. Which of the following effects would most likely be observed?

Accepted Answer

Decreased parasympathetic effects on target organs, such as reduced glandular secretion and decreased gut motility.

Question 3

Which neurotransmitter is released by preganglionic neurons in both the sympathetic and parasympathetic divisions?

Accepted Answer

Acetylcholine

Question 4

Which adrenergic receptor subtype is primarily responsible for vasoconstriction and increased blood pressure?

Accepted Answer

⍺1

Question 5

A person experiences acute stress, triggering the Sympathetic-Adrenal-Medullary (SAM) response. Which hormone is released into the bloodstream, and what is its primary effect?

Accepted Answer

Epinephrine; increases heart rate and prepares the body for immediate action.

Question 6

Which of the following best explains why fingertips have higher tactile precision than the back?

Accepted Answer

Fingertips have smaller receptive fields and more first-order sensory neurons.

Question 7

During the knee-jerk (patellar tendon) reflex, which pathway is responsible for the relaxation of the hamstring muscle?

Accepted Answer

Inhibitory interneuron in the spinal cord inhibits motor neurons to the hamstring.

Question 8

Which of the following is a function of the ⍺2 adrenergic receptor subtype?

Accepted Answer

Inhibits neurotransmitter release (feedback control)

Question 9

A patient with chronic stress is found to have elevated cortisol levels. Which pathway is responsible for this response?

Accepted Answer

Hypothalamic-Pituitary-Adrenal (HPA) pathway

Question 10

Which of the following best describes a monosynaptic reflex?

Accepted Answer

It involves a single synapse between sensory and motor neuron, providing rapid response.

Question 11

Which neurotransmitter is released at the neuromuscular junction in the somatic motor division?

Accepted Answer

Acetylcholine

Question 12

Which receptor type is responsible for fast synaptic transmission at the neuromuscular junction?

Accepted Answer

Nicotinic

Question 13

Which sensory receptor is primarily responsible for detecting changes in blood pressure?

Accepted Answer

Baroreceptor

Question 14

A person touches two points on their forearm and cannot distinguish them as separate. Which of the following best explains this phenomenon?

Accepted Answer

The forearm has few first-order neurons with large receptive fields, leading to low tactile precision.

Question 15

Which of the following is a correct sequence for the HPA axis response to chronic stress?

Accepted Answer

Hypothalamus releases CRH → Pituitary releases ACTH → Adrenal cortex releases cortisol

Question 16

Which of the following equations correctly represents the relationship between stimulus intensity and action potential frequency in sensory neurons?

Accepted Answer

$$	ext{AP frequency} = \frac{	ext{Stimulus Intensity}}{	ext{Threshold}}$$

Question 17

Which of the following best describes the function of mechanoreceptors?

Accepted Answer

Respond to touch, pressure, vibration, and stretch

Question 18

Which of the following is true regarding the adrenal medulla's role in the sympathetic nervous system?

Accepted Answer

It releases epinephrine and norepinephrine into the bloodstream for a widespread sympathetic response.

Question 19

Which of the following is a characteristic of polysynaptic reflexes?

Accepted Answer

They allow integrated, adaptive movements and coordinate multiple muscles.

Peripheral Nervous System Physiology: Structure, Function, and Reflexes

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