Neuroscience Quiz: Neuron Structure and Function

Play an AI-generated podcast conversation about this lesson

What is the primary role of dendrites in a neuron?

To receive impulses from other neurons (correct)

To form myelin sheaths around the axon

To insulate the axon and prevent loss of impulses

To conduct electrical impulses away from the cell body

Which type of neuron carries impulses from receptors to the CNS?

Sensory neurons (correct)

Motor neurons

Glial cells

Relay neurons

How does the sodium-potassium pump contribute to the resting potential of a neuron?

By creating an action potential in the axon

By allowing potassium ions to flow freely across the membrane

By increasing sodium concentration outside the neuron (correct)

By maintaining a higher concentration of potassium inside the neuron (correct)

What defines the resting potential in a neuron?

The state of the neuron when it is not transmitting an impulse Signup and view all the answers

What is one characteristic of motor neurons?

They have a large cell body that lies within the spinal cord or brain. Signup and view all the answers

What defines a nerve impulse?

A rapid change in membrane potential that propagates along the nerve fiber Signup and view all the answers

What is the function of Schwann cells in relation to neurons?

To increase the efficiency of impulse transmission along the axon Signup and view all the answers

What occurs during the action potential in a neuron?

There is a rapid depolarization followed by repolarization of the membrane Signup and view all the answers

What initiates the depolarization phase of an action potential?

Opening of voltage-gated Na+ channels Signup and view all the answers

During repolarization, what is the primary ion that moves out of the axon?

Potassium (K+) Signup and view all the answers

What is the threshold potential that must be reached to trigger an action potential?

$-50mV$ Signup and view all the answers

What causes the depolarization phase of a nerve impulse?

Sodium channels in the membrane open, allowing Na+ ions to diffuse in. Signup and view all the answers

What role do nodes of Ranvier play in myelinated neurons?

They are sites of sodium and potassium ion channel clustering Signup and view all the answers

How do neonicotinoids affect synaptic transmission?

They block acetylcholine receptors irreversibly Signup and view all the answers

What is the primary role of acetylcholinesterase in synaptic transmission?

To break down acetylcholine in the synaptic gap. Signup and view all the answers

Which statement describes saltatory conduction?

It is characterized by action potentials jumping between nodes of Ranvier. Signup and view all the answers

Which neurotransmitter typically acts to inhibit postsynaptic potentials?

GABA Signup and view all the answers

During repolarization, which ion primarily exits the neuron to restore the resting potential?

Potassium ions. Signup and view all the answers

What does summation refer to in neural transmission?

The accumulation of neurotransmitter effects needed to reach threshold potential Signup and view all the answers

Which of the following best describes saltatory conduction?

Action potentials jumping from node to node Signup and view all the answers

What primarily accounts for the unequal pumping of Na+ and K+ ions during resting potential?

The structure of the sodium-potassium pump. Signup and view all the answers

What is the effect of hyperpolarization in a postsynaptic neuron?

Decreased likelihood of firing an action potential Signup and view all the answers

Which ion acts as a chemical signal that triggers the release of neurotransmitters via exocytosis?

Calcium. Signup and view all the answers

What occurs to sodium (Na+) channels during depolarization?

They open and remain open Signup and view all the answers

What effect does myelination have on the speed of nerve impulse conduction?

It increases conduction speed. Signup and view all the answers

Which of the following statements about consciousness is correct?

Consciousness is an emergent property of interacting neurons Signup and view all the answers

What is the function of the sodium-potassium pump after an action potential?

To maintain the resting potential through continuous ion exchange. Signup and view all the answers

Which type of receptor proteins can activate nerve endings in response to environmental stimuli?

Ion channels for positively charged ions Signup and view all the answers

What occurs immediately after depolarization in the action potential sequence?

Repolarization due to efflux of potassium ions. Signup and view all the answers

Which of the following best describes the effect of cocaine on synaptic transmission?

Increases dopamine concentration in the synaptic cleft Signup and view all the answers

How do local currents contribute to the propagation of action potentials along an axon?

They cause regions of the axon to reach threshold potential sequentially. Signup and view all the answers

What characterizes an excitatory postsynaptic potential (EPSP)?

It results from neurotransmitter binding and Na+ influx. Signup and view all the answers

Which of the following accurately describes a synapse?

A junction that allows signal transmission in one direction. Signup and view all the answers