Neural tissue is neurons plus a cast of support cells
Nervous tissue builds both the central brain-and-cord axis and the branching peripheral web. Neurons fire the impulses, yet much of the bulk is neuroglia—astrocytes, microglia, oligodendrocytes, Schwann cells—quietly keeping the wires alive and insulated for clear timing.
Nervous tissue is the working material of both halves of the nervous system: the brain and spinal cord in the centre, and the branching nerves of the periphery. It contains two broad cell families. Neurons carry impulses in and out, while neuroglia help those impulses travel and keep the neurons fed. Its jobs include taking in sensation, integrating signals, steering muscles and glands, keeping the body's internal balance, and supporting thought.
Every neuron has an axon, the long stalk that sends an action potential onward. Dendrites, thin branching arms, pick up neurotransmitters and shift the cell's voltage, and the soma houses the nucleus. At the bulb-shaped axon terminal a tiny synaptic cleft separates one cell from the next; chemicals released there bind receptors on the far side and keep the signal moving. Axons bundled together are called nerves in the periphery and tracts in the brain and cord.
Neurons are sorted by job and by shape. Sensory (afferent) cells report inward, motor (efferent) cells drive muscles and glands, and interneurons knit local circuits within one patch of brain or cord. Multipolar neurons, with three or more processes, dominate the central system; bipolar and pseudounipolar forms are sensory. Unipolar brush cells, excitatory interneurons tipped with a brush of tiny dendrioles, sit in the cerebellum's granular layer.
The glia are smaller and more varied. Star-shaped astrocytes are the most common cell in the brain. Microglia, the smallest glia, act as the central system's resident immune macrophages. Oligodendrocytes wrap central axons in fatty myelin that speeds conduction, and NG2 glia are their precursors; Schwann cells do the myelinating job in the periphery, and satellite cells coat neuron bodies in ganglia. The mix defines the tissue: grey matter is rich in cell bodies and unmyelinated fibres, while white matter is packed with myelinated axons.
Source: Nervous tissue
