9 and 10 test AP Psych

Neuron

Basic building block of the nervous system (nerve cell).

Dendrites

Neuron branches that receive chemical messages and conduct impulses toward the cell body.

Cell Body (Soma)

The cell's life-support center containing the nucleus.

Axon

Neuron extension that passes electrical messages away from soma to other neurons or muscles.

Myelin Sheath

Fatty tissue layer insulating the axon that speeds up neural impulse transmission.

Action Potential

A brief electrical charge (neural impulse) that travels down an axon.

Resting Potential

The negative-inside / positive-outside state of an inactive axon membrane.

-70 mv

Threshold

Minimum level of stimulation required to trigger a neural impulse.

-55mv

Refractory Period

Brief resting pause after a neuron fires during which another impulse cannot occur.

All-or-None Response

Principle that a neuron fires at full strength or not at all.

Synapse (Synaptic Gap)

Tiny fluid-filled gap between sending axon tip and receiving dendrite.

Neurotransmitters

Chemical messengers that cross synaptic gaps to bind to receiving receptor sites.

Reuptake

Reabsorption of excess neurotransmitters by the sending neuron.

Acetylcholine (ACh)

Neurotransmitter for muscle action, learning, memory; undersupply linked to Alzheimer's.

Dopamine

Neurotransmitter for movement, learning, attention; excess linked to schizophrenia, undersupply to Parkinson's.

Serotonin

Neurotransmitter affecting mood, hunger, sleep, arousal; undersupply linked to depression.

Norepinephrine

Neurotransmitter helping control alertness and arousal; undersupply can depress mood.

GABA

Major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia.

Glutamate

Major excitatory neurotransmitter involved in memory; oversupply causes migraines or seizures.

Endorphins

Natural, opiate-like neurotransmitters linked to pain control and pleasure.

Agonist

Molecule that binds to a receptor site to stimulate or mimic a neurotransmitter's response.

Antagonist

Molecule that binds to receptor sites to block or inhibit a neurotransmitter's function.

Nervous System

The body's speedy, electrochemical communication network consisting of all nerve cells.

Central Nervous System (CNS)

The brain and spinal cord.

Peripheral Nervous System (PNS)

Sensory and motor neurons connecting the CNS to the rest of the body.

Nerves

Bundled axons forming neural cables connecting CNS with muscles, glands, and sense organs.

Sensory (Afferent) Neurons

Neurons carrying incoming information from sensory receptors to the CNS.

Motor (Efferent) Neurons

Neurons carrying outgoing information from the CNS to muscles and glands.

Interneurons

Neurons within brain and spinal cord that communicate between sensory inputs and motor outputs.

Somatic Nervous System

Division of PNS controlling voluntary movements of skeletal muscles.

Autonomic Nervous System

Division of PNS controlling involuntary muscle and gland activity of internal organs.

Sympathetic Nervous System

Division of ANS that arouses the body and mobilizes energy in stressful situations (fight-or-flight).

Parasympathetic Nervous System

Division of ANS that calms the body and conserves its energy (rest and digest).

Reflex

A simple, automatic response to a sensory stimulus.

Endocrine System

The body's slow chemical communication system; glands that secrete hormones into the bloodstream.

Hormones

Chemical messengers manufactured by endocrine glands that travel through the bloodstream.

Adrenal Glands

Endocrine glands above kidneys that secrete epinephrine and norepinephrine during stress.

Pituitary Gland

The master endocrine gland; controlled by hypothalamus, regulates growth and other glands.

Review This