psychology: unit 3A

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

A neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body.

The neuron extension that passes messages through its branches to other neurons or to muscles or glands.

A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one sausage-like node to the next.

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

A period of inactivity after a neuron has fired.

a neuron's reaction of either firing (with a full-strength response) or not firing.

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

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, influencing whether that neuron will generate a neural impulse.

A neurotransmitter's reabsorption by the sending neuron.

"Morphine within"—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

A molecule that, by binding to a receptor site, stimulates a response.

A molecule that, by binding to a receptor site, inhibits or blocks a response.

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

The brain and spinal cord.

The sensory and motor neurons that connect the central nervous system to the rest of the body.

Bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs.

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

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

Neurons in the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.

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

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

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

A simple, automatic response to a sensory stimulus, such as the knee-jerk response.

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

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

A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

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