AP Biology Flash Card Chapter 48

Question 1

Interneurons

Answer 1

An association neuron; a nerve cell within the central nervous system that forms synapses with sensory and/or motor neurons and integrates sensory input and motor output.

Question 2

central nervous system (CNS)

Answer 2

the portion of the vertebrate nervous system consisting of the brain and spinal cord

Question 3

peripheral nervous system (PNS)

Answer 3

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

Question 4

dendrite

Answer 4

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

Question 5

axon

Answer 5

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

Question 6

axon hillock

Answer 6

the conical region of a neuron’s axon where it joins the cell body; typically the region where nerve impulses are generated.

Question 7

synaptic terminals

Answer 7

A bulb at the end of an axon in which neurotransmitter molecules are stored and from which they are released.

Question 8

neurotransmitters

Answer 8

a molecule that is released from the synaptic terminal of a neuron at a chemical synapse, diffuses across the synaptic cleft, and binds to the post-synaptic cell, triggering a response

Question 9

synapse

Answer 9

the junction where one neuron communicates with another cell across a narrow gap. Neurotransmitter molecules released by the neuron diffuse across the synapse, relaying messages to the other cell.

Question 10

presynaptic cell

Answer 10

the transmitting cell at a synapse

Question 11

post-synaptic cell

Answer 11

the target cell at a synapse

Question 12

Astrocyte

Answer 12

a glial cell with diverse functions, including providing structural support for neurons, regulating the interstitial environment, facilitating synaptic transmission, and assisting in regulating the blood supply to the brain.

Question 13

Oligodendrocyte

Answer 13

a type of glial cell that forms insulating myelin sheaths around the axon of neurons in the central nervous system.

Question 14

Schwann cells

Answer 14

A type of glial cell that forms insulating myelin sheaths around the axon of neurons in the peripheral nervous system

Question 15

Efferent neurons

Answer 15

(motor) neuron heading away from the brain

Question 16

Afferent neurons

Answer 16

(sensory) neuron heading towards the brain

Question 17

membrane potential

Answer 17

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

Question 18

resting state

Answer 18

the Na/K pump maintains a net negative charge inside the cell and positive outisde the cell by having more Na ions outside than K ions inside

Question 19

depolarization

Answer 19

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

Question 20

repolarization

Answer 20

the Na ion channel closes, K opens, and K ions flow out, Na ions cant flow in. Leads to a net negative charge inside the cell even more negative than the resting potential

Question 21

depolarization

Answer 21

the K ion channel is closed while the Na ion channel is open, letting positive Na cations to flow in and not letting K ions flow out. This results in the cell having a net positive charge on the inside.

Question 22

chemical potential

Answer 22

action potential travels to the tip of the axon and triggers that opening of a voltage-gated Ca2 channel. The voltage from the action potential opens the Ca2 channel and Ca2 ions flow into the axon, these ions trigger vesicles of various neurotransmitters at the end of the axon. THe neurotransmitters activate the post-synaptic ligand-gated Na ion channel, allowing Na to enter the dendrite of the next cell and continue the action potential from the first nerve cell.

Question 23

Hyperpoerization

Answer 23

a change in a cells membrane potential that makes it more negative

Question 24

saltatory conduction

Answer 24

allows electrical current to flow directly from one neuron to another

Question 25

graded potential

Answer 25

magnitude of the change in membrane varies by strength of stimulus.