AP Psychology Neurons ID Terms

neurons

One of two types of cells in the nervous system; the nerve cells that handle the information-processing function.

axon

the part of the neuron that carries information away from the cell body toward other cells

glial cells

the second of two types of cells in the nervous system; provide support, nutritional benefits, and other functions and keep neurons running smoothly; the glue of the neurons

afferent neurons

neurons that carry information about the external environment to the brain and spinal cord via sensory receptors

efferent neurons

neurons that carry information out of the brain and spinal cord to other areas of the body

soma

cell body of a neuron which contains the nucleus

dendrites

treelike fibers projecting from a neuron, which receive information and orient it toward the neuron's cell body

terminal branches

Branched endings of an axon that transmit messages to other neurons

terminal buttons

Small knobs at the end of axons that secrete chemicals called neurotransmitters

vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

Neurotransmitters

chemical substances that are stored in very tiny sacs within the terminal buttons and involved in transmitting information across a synaptic gap to the next neuron

myelin

a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses

myelin sheath

a layer of fat cells that encases and insulates most axons

neurilemma

additional external myelin sheath that is formed by Schwann cells and found only on axons in the peripheral nervous system

synapses

Tiny spaces between neurons; the gaps between neurons are referred to as synaptic gaps.

electrochemical communication

the movement of the action potential down the length of the axon is an electrical event, and movement of the neurotransmitter across the synaptic space represents the chemical portion of the process

neural firing

electrochemical process where electricity travels within the cell and neurotransmitters travel between cells and the synapse.

resting potential

the stable, negative charge of an inactive neuron

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

action potential

the brief wave of positive electrical charge that sweeps down the axon

threshold

the level of stimulation required to trigger a neural impulse

all-or-none principle

the principle that once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity

refractory period

the time following an action potential during which a new action potential cannot be initiated

receptors

parts of the cell membrane that receive the neurotransmitter and initiate or prevent a new electric signal

reuptake

process by which neurotransmitters are taken back into the synaptic vesicles

excitatory neurotransmitters

chemicals released from the terminal buttons of a neuron that excite the next neuron into firing

inhibitory neurotransmitters

chemicals released from the terminal buttons of a neuron that inhibit the next neuron from firing

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

serotonin

A neurotransmitter that affects hunger,sleep, arousal, and mood.

dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

epinephrine

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

norepinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation

fight-or-flight response

activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety

GABA

a major inhibitory neurotransmitter

glutamate

A major excitatory neurotransmitter; involved in memory

long-term potentiation (LTP)

an increase in a synapse's firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory.

endorphins

"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure.

agonists

chemical substances that mimic or enhance the effects of a neurotransmitter on the receptor sites of the next cell, increasing or decreasing the activity of that cell

antagonists

Chemical substances that block or reduce a cell's response to the action of other chemicals or neurotransmitters.

concussion

a bruise like injury of the brain

behavioral genetics

study of hereditary and environmental influences and how it affects behavior and thinking

genome

all of an organism's genetic material

genotype

an individual's genetic heritage; one's actual genetic material

phenotype

an individual's observable characteristics

DNA

deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

genes

the units of hereditary information, consisting of short segments of chromosomes composed of DNA

sensitive period

A limited phase in an animal's development that is the only time when certain behaviors can be learned.

Konrad Lorenz

researcher who focused on critical attachment periods in baby birds, a concept he called imprinting

reciprocal determinism

the interacting influences of behavior, internal cognition, and environment

Heritability

the proportion of observable differences in a group that can be explained by differences in the genes of the group's members

adaptation

inherited characteristic that increases an organism's chance of survival

evolutionary psychology

an approach to psychology focusing on evolutionary ideas such as adaptation, reproduction, and natural selection as the basis for explaining specific human behaviors

genetic mutations

Changes in the genetic material of cells that passes from one generation to another.

epigenetics

the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.