Question 1

Which of the following best describes the function of the blood-brain barrier in the central nervous system (CNS)?

Accepted Answer

It selectively restricts the passage of certain substances from the blood into the brain, protecting neural tissue.

Question 2

A patient presents with loss of sensation and motor control in the right arm after a stroke. Which region of the brain is most likely affected?

Accepted Answer

Left primary motor cortex

Question 3

Which equation correctly represents the Nernst equation for calculating the equilibrium potential for potassium ions ($$K^+) $$across a neuronal membrane?

Accepted Answer

$$E_K = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 4

During a reflex arc, which of the following sequences correctly describes the pathway of a typical somatic reflex?

Accepted Answer

Receptor → Sensory neuron → Integration center → Motor neuron → Effector

Question 5

A patient is unable to feel pain or temperature on the left side of their body below the waist. Which spinal tract is most likely damaged?

Accepted Answer

Right spinothalamic tract

Question 6

Which of the following best explains why demyelinating diseases, such as multiple sclerosis, slow down nerve impulse conduction?

Accepted Answer

They disrupt saltatory conduction by damaging the myelin sheath, forcing impulses to travel continuously along the axon.

Question 7

Which cranial nerve is responsible for the majority of parasympathetic output to the thoracic and abdominal organs?

Accepted Answer

Vagus nerve (Cranial Nerve X)

Question 8

A person steps on a sharp object and immediately withdraws their foot. Which type of reflex is this, and which part of the nervous system mediates it?

Accepted Answer

Polysynaptic withdrawal reflex mediated by the spinal cord

Question 9

Which of the following best describes the role of the cerebellum in motor control?

Accepted Answer

Coordinates and fine-tunes voluntary movements

Question 10

A patient with damage to Broca's area would most likely experience which of the following symptoms?

Accepted Answer

Difficulty producing speech but comprehension remains intact

Question 11

Which equation best represents Ohm's Law as applied to the movement of ions across a neuronal membrane?

Accepted Answer

$$I = \frac{V}{R}$$

Question 12

Which of the following is a function of the hypothalamus?

Accepted Answer

Regulation of body temperature and hunger

Question 13

A patient is unable to move their left leg after a spinal cord injury. Which tract is most likely damaged?

Accepted Answer

Right lateral corticospinal tract

Question 14

Which of the following best describes the function of Schwann cells in the peripheral nervous system (PNS)?

Accepted Answer

They form myelin sheaths around axons in the PNS, increasing the speed of nerve impulse conduction.

Question 15

Which neurotransmitter is released at the neuromuscular junction to stimulate skeletal muscle contraction?

Accepted Answer

Acetylcholine

Question 16

A patient with a lesion in the dorsal root of a spinal nerve would most likely experience which of the following?

Accepted Answer

Loss of sensory input from the affected region

Question 17

Which of the following best explains the effect of a local anesthetic that blocks voltage-gated sodium channels on a neuron?

Accepted Answer

It prevents the generation and propagation of action potentials.

Question 18

Which of the following is a characteristic of the sympathetic division of the autonomic nervous system?

Accepted Answer

It increases heart rate and dilates bronchioles during the 'fight or flight' response.

Question 19

A patient is unable to abduct their eye laterally. Which cranial nerve is most likely damaged?

Accepted Answer

Abducens nerve (Cranial Nerve VI)

Question 20

Which of the following best describes the function of the dorsal columns in the spinal cord?

Accepted Answer

They transmit fine touch, vibration, and proprioceptive information to the brain.

BIO 141 Exam 4 Study Guide: Central and Peripheral Nervous System

Study Guide - Practice Questions

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