Question 1

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

Accepted Answer

They wrap around axons to form myelin sheaths, increasing the speed of nerve impulse conduction.

Question 2

A patient with multiple sclerosis (MS) is experiencing muscle weakness and vision problems. Which cellular structure is primarily affected in this disease?

Accepted Answer

Myelin sheath

Question 3

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

Accepted Answer

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

Question 4

During an action potential, which event occurs immediately after the membrane potential reaches threshold?

Accepted Answer

Voltage-gated sodium channels open, allowing $$Na^+$$ influx.

Question 5

Which of the following statements about graded potentials and action potentials is correct?

Accepted Answer

Graded potentials decrease in amplitude as they travel, while action potentials maintain constant amplitude.

Question 6

A neuron is at rest with a membrane potential of $$-70	ext{mV}. $$What is the primary reason for this negative resting membrane potential?

Accepted Answer

The selective permeability of the membrane to $$K^+$$ ions and the activity of the sodium-potassium pump.

Question 7

Which neurotransmitter is most associated with mood, happiness, and is targeted by many antidepressant drugs?

Accepted Answer

Serotonin

Question 8

What is the main function of the nodes of Ranvier in a myelinated axon?

Accepted Answer

To allow action potentials to jump from node to node, increasing conduction speed.

Question 9

Which glial cell type is responsible for forming the blood-brain barrier and secreting growth factors in the CNS?

Accepted Answer

Astrocytes

Question 10

A patient is unable to fire a second action potential immediately after the first one, no matter how strong the stimulus. This period is called:

Accepted Answer

Absolute refractory period

Question 11

Which process describes the recycling of neurotransmitters after they have been released into the synaptic cleft?

Accepted Answer

Reuptake

Question 12

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

Accepted Answer

Myelination allows action potentials to jump between nodes of Ranvier, reducing the number of ion channels that need to open.

Question 13

Which neurotransmitter is most commonly associated with learning and memory, but excessive release can cause excitotoxicity?

Accepted Answer

Glutamate

Question 14

A patient with amyotrophic lateral sclerosis (ALS) is losing the ability to speak and swallow. What is the underlying cause of ALS?

Accepted Answer

Neurodegenerative disease causing progressive damage to motor neurons in the spinal cord and brain.

Question 15

Which of the following is NOT a function of astrocytes?

Accepted Answer

Forming myelin sheaths around axons.

Question 16

During saltatory conduction, the action potential:

Accepted Answer

Jumps from one node of Ranvier to the next, increasing conduction speed.

Question 17

Which of the following best describes the role of ependymal cells in the central nervous system?

Accepted Answer

They produce cerebrospinal fluid that bathes the brain and spinal cord.

Question 18

Which of the following best describes the difference between sensory and motor neurons?

Accepted Answer

Sensory neurons transmit impulses from receptors in the skin or internal organs towards the CNS, while motor neurons transmit impulses away from the CNS to effectors.

Question 19

Which of the following is a correct sequence of events for neurotransmitter release at a synapse?

Accepted Answer

Action potential arrives at axon terminal → voltage-gated calcium channels open → neurotransmitter vesicles fuse with membrane → neurotransmitter released into synaptic cleft

Study Guide: Nervous Tissue (Anatomy & Physiology Chapter 11)

Guida di studio - Domande di pratica

Study guide - Flashcard