Module 6

Front 1

neuron

Back 1

a nerve cell; the basic building block of the nervous system

Front 2

dendrite

Back 2

the branching extensions of a neuron that receive information and conduct impulses toward the cell body (soma).

Front 3

soma

Back 3

the cell body of a neuron, which contains the nucleus and other parts that keep the cell healthy

Front 4

axon

Back 4

the extension of a neuron through which neural impulses are sent

Front 5

axon terminal

Back 5

the endpoint of a neuron where neurotransmitters are stored

Front 6

action potential

Back 6

a neural impulse; a brief electrical charge that travels down the axon of a neuron

Front 7

refractory period

Back 7

the "recharging phase" when a neuron, after firing, cannot generate another action potential

Front 8

resting potential

Back 8

the state of a neuron when it is at rest and capable of generating an action potential

Front 9

all-or-none principle

Back 9

the principle stating that if a neuron fires it always fires at the same intensity; all action potentials have the same strength

Front 10

synapse

Back 10

the tiny, fluid-filled gap between the axon terminal of one neuron and the dendrite of another

Front 11

neurotransmitter

Back 11

a chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential.

Front 12

excitatory effect

Back 12

a neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or "fire"

Front 13

inhibitory effect

Back 13

a neurotransmitter effect that makes it less likely that a receiving neuron will generate an action potential or "fire"

Front 14

receptor cells

Back 14

specialized cells in every sensory system of the body that can turn other kinds of energy into action potentials (neural impulses) that the brain can process.

Front 15

sensory nerves

Back 15

nerves that carry information from the sense receptors to the spinal cord and brain

Front 16

interneurons

Back 16

nerve cells in the brain and spinal cord responsible for processing information

Front 17

acetylcholine (ACh)

Back 17

a neurotransmitter that triggers muscle contraction and affects learning and memory

Front 18

serotonin

Back 18

a neurotransmitter that affects hunger, sleep, arousal, and mood

Front 19

dopamine

Back 19

a neurotransmitter that affects learning, attention, and emotion

Front 20

agonist

Back 20

a drug that boosts the effect of a neurotransmitter

Front 21

antagonist

Back 21

a drug that blocks the effect of a neurotransmitter

Front 22

motor nerves

Back 22

nerves that carry information away from the brain and spinal cord to the muscles and glands

Front 23

central nervous system (CNS)

Back 23

The brain and the spinal cord

Front 24

Peripheral nervous system (PNS)

Back 24

the sensory and motor nerves that connect the brain and the spinal cord to the rest of the body

Front 25

somatic nervous system

Back 25

the division of the peripheral nervous system that controls the body's skeletal muscles

Front 26

autonomic nervous system

Back 26

the division of the peripheral nervous system that controls the glands and muscles of the internal organs. Its subdivisions are sympathetic (arousing) division and the parasympathetic (calming) division.

Front 27

sympathetic division

Back 27

the part of the autonomic nervous system that arouses the body to deal with perceived threats.

Front 28

parasympathetic divison

Back 28

the part of the automatic nervous system that calms the body

Front 29

endocrine system

Back 29

one of the body's two communication systems; a set of glands that produce hormones, chemical messengers that circulate in the blood

Front 30

hormone

Back 30

a chemical messenger produced by the endocrine glands and circulated in the blood

Front 31

pituitary gland

Back 31

the endocrine system's "master gland" that, in conjunction with the brain, controls the other endocrine glands