absolute refractory period
The minimum length of time after an action potential during which another action potential cannot begin.
A brief change in a neuron's electrical charge.
A chemical that mimics the action of a neurotransmitter.
A chemical that opposes the action of a neurotransmitter.
autonomic nervous system (ANS)
The system of nerves that connect to the heart, blood vessels, smooth muscles, and glands.
A long, thin fiber that transmits signals away from the neuron cell body to other neurons, or to muscles or glands.
central nervous system (CNS)
The brain and the spinal cord.
Branch of psychology concerned with the links between biology and behavior
Branchlike parts of a neuron that are specialized to receive information.
efferent nerve fibers
Axons that carry information outward from the central nervous system to the periphery of the body.
A group of glands that secrete chemicals into the bloodstream that help control bodily functioning.
The chemical substances released by the endocrine glands.
Bundles of neuron fibers (axons) that are routed together in the peripheral nervous system.
Individual cells in the nervous system that receive, integrate, and transmit information.
Chemicals that transmit information from one neuron to another.
The branch of the autonomic nervous system that generally conserves bodily resources.
peripheral nervous system
All those nerves that lie outside the brain and spinal cord.
The "master gland" of the endocrine system; it releases a great variety of hormones that fan out through the body, stimulating actions in the other endocrine glands.
The stable, negative charge of a neuron when it is inactive.
A process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane.
somatic nervous system
The system of nerves that connect to voluntary skeletal muscles and to sensory receptors.
The branch of the autonomic nervous system that mobilizes the body's resources for emergencies.
A junction where information is transmitted from one neuron to the next.
Carry incoming information from the sensory receptors to the brain and spinal cord
Carry outgoing information from the brain and spinal cord to the muscles and glands
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
Layer of fatty tissue segmentally encasing the fibers of many neurons, enables vastly greater transmission speed of neural impulses - linked with multiple sclerosis
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.