Brain

The brain is an organ in the cranium. It is the principal organ of the nervous system. Unlike most other organs, topology has a very major role in function.

Brain
System:
Function:
Origin:
Branches:
Insertion:
Arterial supply:	Blood supply of brain
Venous drainage:
Lymphatic drainage:
Innervation:
Vertebral levels:
Search for Brain in Gray's.

Contents 1 Structure 1.1 Gross Anatomy 1.2 Microscopic Anatomy 1.3 Physiology

Structure

Gross Anatomy

• The brain is often divided into the forebrain, midbrain & hindbrain.

Another way of dividing it is into the brainstem, cerebrum and cerebellum.

• The hindbrain continues into the spinal cord, which leaves the cranium through the foramen magnum.

• Overlying the nervous tissue of the brain, there are three protective coverings - the meninges.

• In addition, the brain also has its own blood supply. Movement between the blood and the brain is regulated by the blood-brain barrier.

• The brain is surrounded by cerebrospinal fluid (C.S.F). This serves the main purpose of cushioning the brain against physical shocks.

Microscopic Anatomy

The brain itself is composed of:

• Neurones
• Neuroglia

Physiology

The subject of brain physiology is covered by neurophysiology. In addition, the biochemistry of neurotransmitters is dealt with by neurochemistry.