The Brain is protected by cranial meninges that are made up of an outer layer called dura mater, a thin middle layer called arachnoid, and an inner layer called pia mater. It is divided into three regions − forebrain, midbrain, and hindbrain.

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

(a) Cerebrum: is the largest part of the brain . Cerebrum is divided into two cerebral hemispheres by a deep cleft. These hemispheres are joined by a tract of nerve fibre known as corpus callosum. The cerebral hemispheres are covered by a layer of cells known as cerebral cortex or grey matter. Cerebrum has sensory regions known as association areas. The innermost part of cerebrum gives an opaque white appearance to the layer and is known as the white matter.

(b) Thalamus:

Thalamus is the main centre of coordination for sensory and motor signalling. 

(c) Hypothalamus:

It lies at the base of thalamus .

Midbrain:

It is located between the thalamus region of the forebrain and pons region of hindbrain. The cerebral aqueduct passes through the midbrain. Corpora quadrigemia are the four round swelling foind in the dorsal portion of the midbrain. 

Hindbrain:

It consists of three regions − pons, cerebellum, and medulla oblongata.

(a) Pons is a band of nerve fibre that lies between medulla oblongata and midbrain. It connects the lateral parts of cerebellar  hemisphere together.

(b) Cerebellum ghas a convoluted surface. 

(c) Medulla oblongata is the posterior and simplest part of the brain. Its lower end extends in the form of spinal cord and leaves the skull through foramen magnum.