Question

What are the divisions of diencephalon?

Answer 1

Hint: The central organ for the nervous system in humans is the brain. Brain along with the spinal cord forms the central nervous system. It consists of the cerebrum, brainstem and cerebellum. It is protected by the skull bones which are present in the head.

Complete answer:
Brain is the central organ in the nervous system. It processes all the information received from the sense organs and also controls most of the activities in the body. Along with the spinal cord it forms the central nervous system of the body. It consists of the cerebrum, brainstem and cerebellum. The skull bones in the head are for the protection of the brain.

Cerebrum is the largest part of the brain and it consists of two cerebral hemispheres. On the inner side of the hemisphere white matter is present and on the outer surface grey matter is present. It is connected with the spinal cord through the brain stem. Diencephalon is present deep inside the hemispheres of the cerebrum. It encloses the third ventricle of the cerebrum.

Diencephalon is divided into four parts:
1. Thalamus: It is the largest division and its primary function is the recognition of the sensory stimulus to the cortex part of the cerebrum. It also plays an important role in motor and limbic functions of the body.
2. Hypothalamus: It is present at the base of the diencephalon, below the cerebral cortex. Its primary function is regulation of homeostasis. It controls the synthesis and release of the neurohormones from the nervous system.
3. Subthalamus: It is a small division of diencephalon which is situated under the optic thalamus. It contains the fibre tracts and the subthalamic nucleus.
4. Epithalamus: It is also a small division of the diencephalon which is present superior to the optic thalamus. It is involved in the secretion of melatonin by the pineal gland which controls the circadian rhythm cycle.

Note:
The central organ of the human nervous system is the brain. It consists of the cerebrum, brainstem and cerebellum. Main function of the brain is recognition of the stimulus received from the sense organs. Diencephalon is present deep inside the hemispheres of the cerebrum and is divided into four parts: thalamus, hypothalamus, subthalamus and epithalamus.