25 - Neurons and membrane potentials

Question 1

Central nervous system

Answer 1

The portion of the nervous system where signal integration occurs; in the vertebrate animals, the brain and spinal cord

Question 2

Peripheral nervous system

Answer 2

The sensory and motor neurons that connect to the central nervous system

Question 3

Axon

Answer 3

a typically long extension, or process, of a neuron that carries nerve impulses away from the cell body toward target cells

Question 4

Dendrite

Answer 4

One of usually numerous, short, highly branched extensions of a neuron that receive signals from other neurons

Question 5

Cell body/ cell soma

Answer 5

The part of a neuron that houses the nucleus and most other organelles

Question 6

Synapse

Answer 6

The junction where a neuron communicates with another cell across a narrow gap via a neurotransmitter or an electrical coupling

Question 7

Neuron

Answer 7

A nerve cell; the fundamental unit of a nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane.

Question 7

Glia

Answer 7

Cells of the nervous system that support, regulate, and augment the functions of neurons

Question 8

Membrane potential

Answer 8

The difference in electrical charge (voltage) across a cell’s plasma membrane due to the differential distributuion of ions. Membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances

Question 9

Na+/K+ pump

Answer 9

A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell

Question 10

K+ leak channel

Answer 10

is a type of protein found in cell membranes that allows potassium ions (K⁺) to move in and out of the cell.

Question 11

Hyperpolarizing

Answer 11

a change in a cell’s membrane potential such that the inside of the membrane becomes more negative relative to the outside. Hyperpolarization reduces the chance that a neuron will transmit a nerve impulse.

Question 12

Depolarizing

Answer 12

A change in a cell’s membrane potential such that the inside of the membrane is made less negative relative to the outside. For example, a neuron membrane is depolarized if a stimulus decreases its voltage from the resting potential of -70 mV in the direction of zero voltage.

Question 13

Action potential

Answer 13

An electrical signal that propagates (travels) along the membrane of a neuron or other excitable cell as a nongraded (all or none) depolarization

Question 14

Resting potential

Answer 14

The membrane potential characteristic of a nonconducting excitable cell, with the inside of the cell more negative than the outside

Question 15

Depolarization

Answer 15

A change in a cell’s membrane potential such that the inside of the membrane is made less negative relative to the outside. For example, a neuron membrane is depolarized if a stimulus decreases its voltage from the resting potential of -70 mV in the direction of zero voltage.

Question 16

Repolarization

Answer 16

is the process by which a cell’s membrane potential returns to its resting state after being depolarized. In simple terms, it’s the cell’s way of resetting itself after an electrical signal, like a nerve impulse, has passed.

Question 17

Undershoot/refractory period

Answer 17

A period, immediately following a response to a stimulation, during which a cell or organ is unresponsive to further stimulation

Question 18

Conduction

Answer 18

the process by which electrical signals, or impulses, are transmitted along nerve cells, or neurons. This involves the movement of ions across the neuron’s membrane, which creates changes in electrical charge that travel along the nerve fiber