The central nervous system is primarily made up of the brain and the spinal cord. These two continuous structures act as the main “control center” for processing information and coordinating body functions.

Core components

  • Brain: Located in the skull and includes the cerebrum, cerebellum, and brainstem, which together handle thinking, memory, movement, balance, and vital functions like breathing and heart rate.
  • Spinal cord: A long cord of nervous tissue running inside the vertebral column, carrying signals between the brain and the rest of the body and coordinating many reflexes.

What the tissue is made of

  • Gray matter: Regions rich in neuron cell bodies and dendrites, where most information processing and synapses occur.
  • White matter: Bundles of myelinated axons that act like “wiring,” rapidly conducting signals between different gray matter areas.

Main cell types

  • Neurons: Specialized nerve cells that generate and transmit electrical and chemical signals, underlying sensation, movement, thought, and emotion.
  • Glial cells: Supporting cells (such as astrocytes, oligodendrocytes, and microglia) that provide structural support, form myelin, maintain the environment around neurons, and participate in immune defense.

Protective structures

  • Meninges: Three protective membranes (dura mater, arachnoid mater, pia mater) that cover the brain and spinal cord.
  • Bone: The skull protects the brain, and the vertebral column protects the spinal cord from mechanical injury.

In simple terms

  • The central nervous system = brain + spinal cord.
  • These are built from neurons and glial cells, organized into gray and white matter, and wrapped in meninges inside protective bone.