Nervous System, Neuron Structure, and Neurotransmission (Vocabulary)

A set of vocabulary flashcards covering neuron structure (dendrites, axon, terminals), communication at the synapse (neurotransmitters, receptor fitting), neural signaling (resting potential, action potential, all-or-none, refractory period), and the major divisions and functions of the nervous system (CNS, PNS, ANS, sympathetic, parasympathetic, somatic), plus related concepts like neuroplasticity and hormones.

Dendrite

Branch-like extensions of a neuron that receive information from other neurons.

Axon

Long fiber that conducts electrical impulses away from the neuron's cell body toward the axon terminals.

Axon terminal (terminal button)

End of the axon where neurotransmitters are released into the synapse.

Synapse

The small gap between neurons where neurotransmitters cross to transmit signals to the next neuron.

Neurotransmitters

Chemical messengers that regulate mood, sleep, hunger, pain, and emotions; released at the synapse and can be mimicked or blocked by drugs.

Resting potential

The neuron's inactive state with a balanced membrane potential and no incoming message.

Action potential

The all-or-none electrical impulse that travels down the axon when threshold is reached, triggering transmission of the signal.

All-or-none principle

The idea that a neuron fires completely or not at all; there is no partial firing.

Refractory period

The recovery period after an action potential during which the neuron returns to resting state and cannot fire again immediately.

Neural impulse

The process of transmitting information through electrical and chemical signals in the nervous system (often referring to the action potential).

Lock-and-key (receptor) model

Neurotransmitters must fit specific receptor sites on the next neuron to have an effect.

Neurotransmitters vs hormones

Neurotransmitters are brain chemicals released at synapses; hormones are chemical messengers released by glands into the bloodstream.

Autonomic nervous system (ANS)

Division of the peripheral nervous system that regulates involuntary functions; subdivided into sympathetic and parasympathetic.

Sympathetic nervous system

Part of the ANS that arouses the body for danger (fight-or-flight), increasing alertness and physiological readiness.

Parasympathetic nervous system

Part of the ANS that returns the body to a resting state after arousal (rest-and-digest).

Central nervous system (CNS)

The brain and spinal cord; the main control center that coordinates activity and communicates with the body.

Peripheral nervous system (PNS)

All nerves outside the CNS; connects the CNS to the rest of the body and is divided into autonomic and somatic.

Somatic nervous system

Subdivision of the PNS that governs voluntary movement and processes sensory information (motor and sensory components).

Neuroplasticity (neural connections)

The brain's ability to form and strengthen neural connections through learning and experience; often involves creating more connections rather than generating many new neurons.

Fight-or-flight response

A sympathetic nervous system activation in response to danger, preparing the body for quick action.