AP Psych 1.2-1.3a Vocab

nervous system

the body's

speedy, electrochemical

communication network,

consisting of all the nerve cells

of the peripheral and central

nervous systems.

central nervous system

(CNS)

the brain and spinal cord, the decision maker

peripheral nervous system

(PNS)

the sensory and motor

neurons that connect the central

nervous system (CNS) to the rest

of the body, sends messages to the rest of the body

nerves

bundled axons that

form neural cables connecting

the central nervous system with

muscles, glands, and sensory

organs.

sensory (afferent) neurons

neurons that carry incoming

information from the body's

tissues and sensory receptors to

the brain and spinal cord.

motor (efferent) neurons

neurons that carry outgoing

information from the brain and

spinal cord to the muscles and

glands.

interneurons

neurons within

the brain and spinal cord; they

communicate internally and

process information between

the sensory inputs and motor

outputs.

somatic nervous system

the

division of the peripheral

nervous system that controls the

body's skeletal muscles. Also

called the skeletal nervous system.

autonomic nervous system (ANS)

the

part of the peripheral nervous

system that controls the glands

and the muscles of the internal

organs (such as the heart). Its

sympathetic division arouses; its

parasympathetic division calms.

sympathetic nervous

system

the division of the

autonomic nervous system that

arouses the body, mobilizing its

energy.

parasympathetic nervous

system

the division of the

autonomic nervous system that

calms the body, conserving its

energy.

reflex

simple, automatic

response to a sensory stimulus,

such as the knee-jerk reflex.

neuron

a nerve cell; the basic

building block of the nervous

system.

cell body

the part of a neuron

that contains the nucleus; the

cell's life-support center.

dendrites

a neuron's often

bushy, branching extensions that

receive and integrate messages,

conducting impulses toward the

cell body.

axon

the segmented neuron

extension that passes messages

through its branches to other

neurons or to muscles or glands.

myelin [MY-uh-lin] sheath

a fatty tissue layer segmentally

encasing the axons of some

neurons; it enables vastly greater

transmission speed as neural

impulses hop from one node to

the next.

glial cells (glia)

cells in the

nervous system that support,

nourish, and protect neurons;

they may also play a role in

learning, thinking, and memory.

action potential

a neural

impulse; a brief electrical charge

that travels down an axon.

threshold

the level of

stimulation required to trigger a

neural impulse.

refractory period

in neural

processing, a brief resting pause

that occurs after a neuron

has fired; subsequent action

potentials cannot occur until the

axon returns to its resting state.

all-or-none response

a

neuron's reaction of either firing

(with a full-strength response) or

not firing.

synapse

the junction

between the axon tip of the

sending neuron and the dendrite

or cell body of the receiving

neuron. The tiny gap at this

junction is called the synaptic gap

or synaptic cleft.

neurotransmitters

chemical

messengers that cross the synaptic

gap between neurons. When

released by the sending neuron,

neurotransmitters travel across the

synapse and bind to receptor sites

on the receiving neuron, thereby

influencing whether that neuron

will generate a neural impulse.:

reuptake

a neurotransmitter's

reabsorption by the sending

neuron.

endorphins

"morphine within"; natural,

opioid-like neurotransmitters

linked to pain control and to

pleasure.

agonist

molecule that

increases a neurotransmitter's

action

antagonist

molecule

that inhibits or blocks a

neurotransmitter's action.

endocrine [EN-duh-krin]

system

he body's "slow"

chemical communication system;

a set of glands and fat tissue

that secrete hormones into the

bloodstream.

hormones

chemical messengers

that are manufactured by the

endocrine glands, travel through

the bloodstream, and affect other

tissues.