Question

Write a short note on the following:

Forebrain 

Answer 1

Forebrain

It is the main thinking part of the brain. It consists of cerebrum, thalamus, and hypothalamus.

1. Cerebrum:
   • cerebrum is the largest part of the brain and constitutes about four-fifth of its weight. The cerebrum is divided into two cerebral hemispheres by a deep longitudinal cerebral fissure.
   • These hemispheres are joined by a tract of nerve fibres known as the corpus callosum. The cerebral hemispheres are covered by a layer of cells known as the cerebral cortex or grey matter.
   • The cerebrum has sensory regions known as association areas that receive sensory impulses from various receptors as well as from motor regions that control the movement of various muscles.
   • The innermost part of cerebrum gives an opaque white appearance to the layer and is known as the white matter.
2. Thalamus:
   • The thalamus is the main centre of coordination for sensory and motor signalling.
   • It is wrapped in the cerebrum.
3. Hypothalamus:
   • It lies at the base of the thalamus and contains a number of centres that regulate body temperature and the urge for eating and drinking.
   • Some regions of cerebrum, along with hypothalamus, are involved in the regulation of sexual behaviour and expression of emotional reactions such as excitement, pleasure, fear, etc.