Q: During an action potential, which ion is primarily responsible for the depolarization phase?

Sodium (Na\textsuperscript{+}) influx

Q: Which of the following is a correct sequence of events for synaptic transmission at a chemical synapse?

Action potential arrives at axon terminal, Ca\textsuperscript{2+} enters, neurotransmitter is released, postsynaptic receptors are activated.

Question 1

Which of the following best describes the three major functions of the nervous system, as illustrated by the scenario of touching a hot stove?

Accepted Answer

Sensory input detects heat, integration processes the information, and motor output causes muscle contraction to withdraw the hand.

Question 2

Which of the following statements correctly compares the central nervous system (CNS) and the peripheral nervous system (PNS)?

Accepted Answer

The CNS consists of the brain and spinal cord, while the PNS includes all neural tissue outside the CNS.

Question 3

Which glial cell type is responsible for forming the myelin sheath in the central nervous system?

Accepted Answer

Oligodendrocytes

Question 4

A patient is diagnosed with multiple sclerosis, a disease that damages myelin in the CNS. Which of the following is a likely consequence of this pathology?

Accepted Answer

Slowed or blocked action potential conduction along affected neurons

Question 5

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

Accepted Answer

Graded potentials decrease in magnitude with distance, while action potentials are all-or-none and do not diminish as they travel.

Question 6

Which equation correctly represents Ohm's Law as it applies to neurophysiology?

Accepted Answer

$$V = I 	imes R$$

Question 7

During an action potential, which ion is primarily responsible for the depolarization phase?

Accepted Answer

Sodium (Na	extsuperscript{+}) influx

Question 8

Which of the following best explains why action potentials do not travel backward toward the dendrites?

Accepted Answer

The refractory period prevents the reopening of voltage-gated Na	extsuperscript{+} channels in the region just depolarized.

Question 9

Which of the following is a correct sequence of events for synaptic transmission at a chemical synapse?

Accepted Answer

Action potential arrives at axon terminal, Ca	extsuperscript{2+} enters, neurotransmitter is released, postsynaptic receptors are activated.

Question 10

Which of the following best describes saltatory conduction?

Accepted Answer

Action potentials jump from one node of Ranvier to the next, increasing conduction speed.

Question 11

Which of the following is NOT a function of cerebrospinal fluid (CSF)?

Accepted Answer

Directly transmitting nerve impulses between neurons

Question 12

Which of the following correctly lists the path of cerebrospinal fluid (CSF) through the CNS?

Accepted Answer

Lateral ventricles → third ventricle → cerebral aqueduct → fourth ventricle → subarachnoid space

Question 13

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

Accepted Answer

It selectively restricts the passage of substances from the blood into the CNS.

Question 14

A patient presents with loss of voluntary motor control on the right side of the body and difficulty speaking. Which lobe of the cerebral cortex is most likely affected?

Accepted Answer

Left frontal lobe

Question 15

Which cranial nerve is responsible for the sense of smell?

Accepted Answer

Olfactory nerve (Cranial Nerve I)

Question 16

Which of the following best describes the difference between spatial summation and temporal summation at a synapse?

Accepted Answer

Spatial summation involves multiple presynaptic neurons firing simultaneously; temporal summation involves one presynaptic neuron firing rapidly.

Question 17

Which of the following is a correct pairing of a glial cell and its function in the CNS?

Accepted Answer

Microglia: act as immune cells by phagocytosing debris and pathogens

Question 18

Which of the following best describes the function of the dorsal root of the spinal cord?

Accepted Answer

It contains sensory neuron axons entering the spinal cord.

Question 19

Which of the following is a characteristic shared by all neurons?

Accepted Answer

They are excitable and can generate action potentials.

Question 20

Which of the following is a correct description of the meninges covering the CNS?

Accepted Answer

From superficial to deep: dura mater, arachnoid mater, pia mater

Unit 5 Neurophysiology & CNS Study Guide – Step-by-Step Guidance

Study Guide - Practice Questions

Study Guide - Flashcards