The Human Brain
The human brain is enclosed in a bony case called the cranium. An adult human brain weighs about three pounds and consists of billions of neurons. Three layers of connective tissues called meninges and the fluid present in these layers protect the brain. The brain can be divided into three main parts, called fore brain, mid brain and
(a) Fore brain
Fore brain is the largest part of the brain. It consists of three main parts, i.e. Cerebrum, thalamus, and hypothalamus. Cerebrum is the top most and the largest part of the brain. It is divided into right and left cerebral hemispheres. The right cerebral hemisphere controls movement and activities of the left side of the body, while the left cerebral hemisphere controls the right side of the body. Cerebrum is the control centre of many sensory areas like sight, speech, smell, taste and hearing. It is also concerned with learning, thinking, intelligence, memory and voluntary moments.
Inside the cerebrum, there is a small structure called thalamus. It acts as a processing centre between the body and the cerebrum by recieving sensary information like touch and sound and carrying them to the cerebrum. At the base of the thalamus is the Hypothalamus, which regulates body temperature, hunger and thirst.
(b) Mid brain
It is the central part of the brain. Its basic function is to transfer information and impulses between the forebrain and the hind brain. This part of the brain is associated with vision, hearing, sleep/wake amd temperature regulation.
(c) Hind brain
The hind brain consists of three, i.e. Cerebellum, Pons and Medulla oblongata.
Cerebellum is the second largest part of the brain. It is mainly concerned with posture, balance and locomotion of the body. Pons is a small oval structure present above the medulla oblongata. It serves as a bridge for conduction of impulses between the cerebrum, medulla oblongata and the cerebellum. It is concerned with the rate of breathing, sleeping and also regulate eye moment. Medulla oblongata connects the brain to the spinal cord. It controls heart beat, swallowing, vomiting, coughing, sneezing, digestion and breathing etc.