Nervous tissue
Nervous tissue consists of neurons and supporting glial cells that receive, process, and transmit electrical and chemical signals.
Neuron: An excitable cell that receives and transmits information through electrical signals and chemical communication. Neurons carry the signals that distinguish nervous tissue from other tissues.
Action potential: A brief, traveling reversal of a cell membrane's electrical potential that carries signals along excitable cells. Action potentials propagate signals along neuronal axons.
Central nervous system: The brain and spinal cord, which integrate information and coordinate bodily functions. Its gray and white matter organize nervous tissue for central processing and communication.
Epithelial tissue: Tissue whose closely packed cells cover body surfaces, line cavities, and form glands. Epithelia chiefly form barriers and linings rather than conduct neuronal signals.
Neuroglia: Non-neuronal cells in nervous tissue that support, protect, nourish, and regulate neurons. Glial cells maintain the conditions neurons need to function.
Synapse: A specialized junction where a neuron communicates with another cell, usually by chemical or electrical signals. Synapses transfer information between neurons or from neurons to target cells.
Peripheral nervous system: Nerves and ganglia outside the brain and spinal cord that connect them with the rest of the body. Its nerves carry signals between central nervous tissue and peripheral targets.
Connective tissue: Tissue that supports, binds, or separates other tissues, often with abundant extracellular matrix. Its structural matrix contrasts with nervous tissue's cell-centered signaling organization.
Astrocyte: A star-shaped glial cell in the central nervous system that regulates its chemical environment and supports synapses. Astrocytes help stabilize the local environment around active neurons.
Neurotransmitter: A chemical messenger released by a neuron that alters the activity of a target cell. Neurotransmitters carry many signals across chemical synapses.