Stephen J. Schueler, M.D.

Overview Symptoms Conditions Types Anatomy

Neurological Disease Anatomy

To better understand neurological disease, it helps to understand the anatomy of the brain and nervous system.

The nervous system is composed of the brain, spinal cord, peripheral nerves, and autonomic nervous system.

Brain Anatomy
The brain is well protected by:

  • The scalp
  • The skull
  • The dura
    • A tough 3-layer sheath that surrounds the brain and spinal cord
    • Layers include the dura mater (strongest layer), arachnoid mater (middle layer), and pia mater (closest to the brain)

The brain is a complicated structure containing many parts. These include:
  • The cerebrum:
    • Made up of two cerebral hemispheres that are connected in the middle
    • It is the largest part of the brain
    • Each area of the cerebrum performs an important function, such as language or movement
    • Higher thought (cognition) comes from the frontal cortex (front portion of the cerebrum)
    • Outside of the cerebrum are blood vessels
    • There are fluid-filled cavities and channels inside the brain
  • The cerebellum:
    • Located in the lower, back part of the skull
    • Controls movement and coordination
  • The brainstem and pituitary gland:
    • Responsible for involuntary functions such as breathing, body temperature, and blood pressure regulation
    • Pituitary gland is the "master gland" that controls other endocrine glands in the body, such as the thyroid and adrenal glands
  • The cranial nerves:
    • Twelve large nerves exit the bottom of the brain to supply function to the senses such as hearing, vision, and taste
  • The cerebral blood vessels:
    • A complicated system that supplies oxygenated blood and nutrients to the brain

The blood supply to the brain is divided into two main parts:
  • Anterior cerebral circulation:
    • The front of the brain is supplied by the paired carotid arteries in the neck.
  • Posterior cerebral circulation:
    • The back portion of the brain is supplied by the paired vertebral arteries in the spine.

Anatomy examples:
  • Carotid artery branches shown on arteriogram
  • Cerebral arteries viewed in cross-section through middle of brain
  • Cerebral arteries viewed from bottom of brain
  • Cerebral arteries on enhanced CT scan
  • Cerebral arteries on arteriogram

Spinal Cord Anatomy
  • Bones of the cervical, thoracic and lumbar spine
  • Front view of the spine and spinal cord
  • Cross sectional view
  • The conus medullaris is the end of the spinal cord in the back.
  • The spinal cord ends in the lumbar spine at the level of L1 to L2
  • The cauda equina is a bundle of nerves at the bottom of the spinal cord.
    • Nerves of the cauda equina supply the bladder, rectum, perineum, and legs.

FreeMD is provided for information purposes only and should not be used as a substitute for evaluation and treatment by a physician. Please review our terms of use.