Question 1

Which of the following best describes the function of the sodium-potassium ATPase pump in maintaining the resting membrane potential ($$RMP) of a $$neuron?

Accepted Answer

It actively transports $$3$$ sodium ions out of the cell and $$2$$ potassium ions into the cell, maintaining a negative $$RMP.$$

Question 2

A patient presents with loss of sensation in the right hand. Which structure is most likely damaged, considering the decussation of sensory pathways?

Accepted Answer

Left primary somatosensory cortex

Question 3

Which neuroglial cell is responsible for myelinating axons in the peripheral nervous system ($$PNS$$), and how does its function differ from its central nervous system ($$CNS) $$counterpart?

Accepted Answer

Schwann cell; it myelinates a single axon in the $$PNS$$, whereas oligodendrocytes myelinate multiple axons in the $$CNS$$

Question 4

Which equation best represents the Nernst equation for calculating the equilibrium potential ($$E_{ion}) $$for a given ion across a neuronal membrane?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \left( \frac{[ion]_{out}}{[ion]_{in}} \right)$$

Question 5

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Myelinated axons allow action potentials to jump from node to node via saltatory conduction.

Question 6

A local anesthetic blocks voltage-gated sodium channels in a neuron. What is the most immediate effect on neuronal function?

Accepted Answer

The neuron cannot generate an action potential due to failure of depolarization.

Question 7

Which of the following best describes the difference between graded potentials and action potentials?

Accepted Answer

Graded potentials occur in dendrites and cell bodies, while action potentials occur in axons.

Question 8

Which neurotransmitter is most commonly associated with inhibitory postsynaptic potentials ($$IPSP) in $$the central nervous system ($$CNS$$)?

Accepted Answer

GABA (gamma-aminobutyric acid)

Question 9

A patient with hydrocephalus has impaired reabsorption of cerebrospinal fluid ($$CSF). $$Which structure is most likely dysfunctional?

Accepted Answer

Arachnoid villi (granulations)

Question 10

Which cranial nerve is responsible for the sense of smell, and what is its classification?

Accepted Answer

Olfactory nerve ($$I$$); sensory

Question 11

Which of the following best describes the function of the blood-brain barrier?

Accepted Answer

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

Question 12

Which of the following is a characteristic of a monosynaptic reflex arc?

Accepted Answer

It involves only one synapse between a sensory neuron and a motor neuron.

Question 13

Which equation best represents Ohm's Law as applied to neuronal membrane potential?

Accepted Answer

$$V = I 	imes R$$

Question 14

Which of the following best explains the clinical significance of dermatomes?

Accepted Answer

They map the sensory innervation of skin regions to specific spinal nerves, aiding in diagnosis of nerve damage.

Question 15

Which of the following is true regarding the arrangement of gray and white matter in the brain and spinal cord?

Accepted Answer

In the brain, gray matter is superficial and white matter is deep; in the spinal cord, white matter is superficial and gray matter is deep.

Question 16

Which of the following best describes the function of the reticular activating system ($$RAS$$)?

Accepted Answer

It maintains consciousness and alertness by filtering sensory input.

Question 17

Which of the following best describes temporal summation at a chemical synapse?

Accepted Answer

A single presynaptic neuron releases neurotransmitter repeatedly in rapid succession, causing postsynaptic potentials to summate.

Question 18

Which of the following is a function of the limbic system?

Accepted Answer

Processing emotions and formation of long-term memories

Question 19

Which of the following best describes the mechanism by which a neurotoxin such as tetrodotoxin affects neuronal function?

Accepted Answer

It blocks voltage-gated sodium channels, preventing action potential generation.

Nervous Tissue, Brain, and Spinal Cord: Study Guide for BIOL 203 Exam 3

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