AP Psychology Nervous System

glial cells

cells in the nervous system that support, nourish, and protect neurons.

neuron

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

sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

motor 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 that communicate internally and intervene between the sensory inputs and motor outputs.

dendrites

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.

axon terminal

the end of the axon that releases neurotransmitters.

cell body (soma)

a cell's life support center, get messages from the dendrites.

myelin sheath

a layer of fatty tissue segmentally encasing the fibers of many neurons; allows for greater transmission speed of neural impulses as the impulse hops from one node to the next.

action potential

a neural impulse; a brief electrical charge that travels down an axon.

resting potential

This positive-outside/negative-inside state makes for the axon's surface to be permeable.

threshold

the level of stimulation required to trigger a neural impulse.

antagonists

bind to receptors but their effect is instead to block a neurotransmitter's functioning.

agonists

produce a temporary 'high' by amplifying normal sensations of arousal or pleasure.

refractory period

a resting period after orgasm, during which a man cannot achieve another orgasm.

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. Known as the____gap.

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons.

inhibitory signals

when you know something negative is going to occur and will have bad results and you avoid it.

excitatory signals

when you know something good is going to have positive results and you do it again.

reuptake

a neurotransmitter's reabsorption by the sending neuron.

undersupply

leads to seizures, tremors, and insomnia.

central nervous system

the brain and spinal cord.

peripheral nervous system

this division of the nervous system has to do with the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

autonomic nervous system

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

this nervous system is the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy.

somatic nervous system

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

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in the "fight-or-flight" response.

fight-or-flight

states that animals react to threats with a general discharge of the sympathetic nervous system, priming the animal for fighting or fleeing.

adrenaline (epinephrine)

These hormones increase heart rate, blood pressure, and blood sugar, providing us with a surge of energy.

pituitary gland

the endocrine system's most influential gland. Under the influence of the hypothalamus, regulates growth and controls the endocrine glands.

hypothalamus

a neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

ovaries

a pair of endocrine glands that secrete estrogen.

testes

a pair of endocrine glands that create testosterone.

endocrine glands

these secrete another form of chemical messengers, hormones, which travel through the bloodstream and affect other tissues.