Question 1

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

Accepted Answer

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

Question 2

A patient is experiencing muscle weakness due to a lack of acetylcholine release at the neuromuscular junction. Which step in synaptic transmission is most likely impaired?

Accepted Answer

The exocytosis of synaptic vesicles containing acetylcholine from the presynaptic neuron.

Question 3

Which of the following ions is primarily responsible for the depolarization phase of the action potential in a neuron?

Accepted Answer

Sodium ($Na^+$)

Question 4

A researcher measures the resting membrane potential of a neuron and finds it to be $-70\ \mathrm{mV}$. Which of the following best explains the maintenance of this potential?

Accepted Answer

Active transport of $Na^+$ out of the cell and $K^+$ into the cell by the sodium-potassium pump.

Question 5

Which of the following best describes spatial summation in neuronal signaling?

Accepted Answer

Simultaneous stimulation of a postsynaptic neuron by multiple presynaptic neurons at different locations.

Question 6

A patient is diagnosed with multiple sclerosis, a disease that damages myelin in the central nervous system. Which of the following is a likely consequence?

Accepted Answer

Slowed or blocked propagation of action potentials due to loss of saltatory conduction.

Question 7

Which of the following best describes the difference between an EPSP (excitatory postsynaptic potential) and an IPSP (inhibitory postsynaptic potential)?

Accepted Answer

EPSPs result from the influx of $Na^+$ or $Ca^{2+}$, while IPSPs often result from the influx of $Cl^-$ or efflux of $K^+$.

Question 8

Which of the following is a function of the thalamus in the brain?

Accepted Answer

Relay and processing of sensory information to the cerebral cortex.

Question 9

A person touches a hot stove and quickly withdraws their hand. Which of the following best describes the neural pathway involved in this reflex?

Accepted Answer

The signal passes from a sensory neuron to an interneuron in the spinal cord, then to a motor neuron that activates the muscle.

Question 10

Which neurotransmitter is released by all preganglionic neurons in both the sympathetic and parasympathetic divisions of the autonomic nervous system?

Accepted Answer

Acetylcholine

Question 11

A patient is unable to form new long-term memories but can recall events from years ago. Which brain region is most likely damaged?

Accepted Answer

Hippocampus

Question 12

Which of the following best explains why the central nervous system (CNS) relies on glucose as its primary energy source?

Accepted Answer

Glucose can cross the blood-brain barrier via facilitated diffusion.

Question 13

Which of the following best describes the difference between tonic and phasic receptor adaptation?

Accepted Answer

Tonic receptors maintain a response as long as the stimulus is present, while phasic receptors respond only at the beginning or end of a stimulus.

Question 14

A drug blocks voltage-gated potassium channels in neurons. What effect would this have on the action potential?

Accepted Answer

It would prolong the repolarization phase, making the action potential last longer.

Question 15

Which of the following best describes the role of the sodium-potassium pump ($Na^+/K^+$-ATPase) in neurons?

Accepted Answer

It actively transports $3\ Na^+$ out of the cell and $2\ K^+$ into the cell, using ATP.

Question 16

A patient has damage to the Broca's area of the brain. Which symptom would you most likely observe?

Accepted Answer

Difficulty producing coherent speech.

Question 17

Which of the following best describes the function of interneurons in a reflex arc?

Accepted Answer

They connect sensory and motor neurons within the CNS, allowing for integration of information.

Question 18

Which of the following is true regarding the propagation of an action potential along a myelinated axon?

Accepted Answer

The action potential jumps from one node of Ranvier to the next in a process called saltatory conduction.

Question 19

A person is exposed to a toxin that increases the permeability of neuronal membranes to $K^+$. What is the most likely effect on the resting membrane potential?

Accepted Answer

The resting membrane potential would become more negative (hyperpolarized).

Nervous System: Structure, Function, and Physiology – Study Guide Notes

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