- The brain is the main controlling part of the nervous system and is safely located in the cranial cavity.
- The brain is covered by protective layers called the Meninges.
- Cavities present in various parts of the brain are called ventricles. The ventricles are filled with cerebrospinal fluid.
- This fluid supplies nutrients to the brain and also protects it from shock.
- The brain of an adult human weighs about 1300 -1400 grams and consists of approximately 100 million neurons.
- The left side of our brain controls the right side of our body and right side of our brain controls left side of the body.
- In addition, the left side of the brain controls our speech and conversation, writing, logical thinking etc., whereas the right side controls artistic abilities.
Human brain is made up of following parts:
(a) Cerebrum:
- This is the largest part of the brain and consists of two cerebral hemispheres. These hemispheres are joined with each other with the help of tough fibres and nerve tracts.
- The cerebrum occupies two-thirds of the brain. Hence, it is also called as large brain.
- Its surface has deep, irregular ridges and grooves which are called convolutions, convolution increases the surface area of the cerebrum and therefore a large number of nerve cells can be accommodated.
(b) Cerebellum:
- This is the smaller part of the brain situated below the cerebrum at the back of the cranial cavity.
- Its surface shows shallow grooves instead of deep convolutions.
(c) Medulla Oblongata:
- This is the hind-most part of the brain.
- There are two triangular swollen structures called pyramids on the upper side of medulla oblongata.
- The medulla oblongata continues downwards the spinal cord.
