Question 1

Which ion is primarily responsible for the resting membrane potential of a neuron, and what is its relative concentration inside versus outside the cell?

Accepted Answer

Potassium ($$K^+) is $$higher inside the cell than outside, and its movement out of the cell helps maintain the resting membrane potential.

Question 2

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

Accepted Answer

Voltage-gated sodium channels open, causing rapid influx of $$Na^+$$ ions.

Question 3

Which neurotransmitter is classified as an excitatory neurotransmitter and is most commonly found at neuromuscular junctions?

Accepted Answer

Acetylcholine

Question 4

A patient is given a drug that blocks the reuptake of serotonin in the synaptic cleft. What is the most likely effect of this drug?

Accepted Answer

Increased serotonin levels in the synaptic cleft, potentially improving mood.

Question 5

Which of the following best describes the difference between metabotropic and ionotropic neurotransmitter receptors?

Accepted Answer

Ionotropic receptors form ion channels that open directly in response to neurotransmitter binding, while metabotropic receptors activate second messenger systems.

Question 6

Which process is responsible for the release of neurotransmitters from presynaptic cells?

Accepted Answer

Exocytosis triggered by influx of $$Ca^{2+}$$ ions

Question 7

A neuron receives both excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs). Which of the following best describes how the neuron decides whether to fire an action potential?

Accepted Answer

The neuron fires if the sum of EPSPs brings the membrane potential above threshold, overcoming IPSPs.

Question 8

Which of the following is a function of the blood-brain barrier?

Accepted Answer

It prevents the entry of most large or hydrophilic molecules, protecting the CNS from toxins.

Question 9

Which of the following best explains why adaptation occurs in sensory receptors?

Accepted Answer

Sensory receptors decrease their response to constant stimuli, allowing the nervous system to focus on new or changing stimuli.

Question 10

Which neurotransmitter is released by sympathetic postganglionic neurons, and what is its primary effect on target organs?

Accepted Answer

Norepinephrine; increases heart rate and decreases digestive activity

Question 11

A patient presents with muscle weakness and fatigue. Laboratory tests reveal a defect in acetylcholine release at the neuromuscular junction. Which process is most likely impaired?

Accepted Answer

Exocytosis of neurotransmitter vesicles

Question 12

Which of the following best describes the role of the corpus callosum in the central nervous system?

Accepted Answer

It transmits signals between the left and right cerebral hemispheres.

Question 13

Which of the following is a key difference between the sympathetic and parasympathetic divisions of the autonomic nervous system?

Accepted Answer

Sympathetic division prepares the body for 'fight or flight', while parasympathetic promotes 'rest and digest' functions.

Question 14

Which of the following best explains the concept of temporal summation in neuronal signaling?

Accepted Answer

A single synapse is activated repeatedly in rapid succession, causing the postsynaptic potentials to add together.

Question 15

Which neurotransmitter is primarily involved in mood regulation and is often targeted by antidepressant medications?

Accepted Answer

Serotonin

Question 16

A person is exposed to a loud, continuous noise. Over time, their ability to perceive the noise decreases. Which sensory phenomenon does this illustrate?

Accepted Answer

Sensory adaptation

Question 17

Which of the following equations best represents the Nernst equation for calculating the equilibrium potential of an ion across a membrane?

Accepted Answer

$$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion outside}]}{[	ext{ion inside}]} ight)$$

Question 18

Which of the following is true regarding the difference between perception and sensation?

Accepted Answer

Perception is the conscious interpretation of sensory information, while sensation is the initial detection of stimuli.

Question 19

Which neurotransmitter is released by parasympathetic postganglionic neurons, and what is its effect on the heart?

Accepted Answer

Acetylcholine; decreases heart rate

Question 20

A person is unable to distinguish between two closely spaced points on their skin. Which concept does this illustrate, and what does it suggest about the receptive field in that area?

Accepted Answer

Low sensory discrimination; large receptive field

Study Guide: Nerve Conduction, Neurotransmitters, CNS, Special Senses, and Autonomic Nervous System

Study Guide - Practice Questions

Study Guide - Flashcards