Name: Organisation of the Human Nervous System
Uploaded: 2019-07-19
Duration: 4 min
Description: The nervous system as a whole is divided into two subdivisions: the central nervous system (CNS) and the peripheral nervous system (PNS).

Question

Write a short note on human brain.

Accepted Answer

The central nervous system consists of the brain and the spinal cord. The brain is situated inside the cranium (skull bone). The adult human brain consists of an estimated 100 billion neurons. The Brain remains covered with the three layers of meninges. The space between the membranes is filled with the watery fluid, called the cerebral-spinal fluid. The brain is divided into the following parts:

Forebrain: It consists of two parts:

Cerebrum: The cerebrum is the largest portion of the brain. The cerebrum consists of two cerebral hemispheres. Each cerebral hemisphere is hollow internally and the walls have two regions: an outer cortex which contains many layers of cytons and is called the grey matter. The inner portion of the cerebrum is called the white matter which contains myelinated sheaths of the axons. The cerebrum is the site of intelligence and controls all voluntary actions.

Diencephalon: It is further divided into two parts: thalamus and hypothalamus. The thalamus evaluates the importance of incoming signals and accordingly passing to the cerebrum. The hypothalamus contains the neural centres for hunger, thirst, and the regulation of body temperature and pituitary secretion.

Midbrain: It consists of four lobes. This portion of the brain controls the visual reflexes and auditory reflexes.

Hindbrain: It consists of the following parts:

Cerebellum: It is the second-largest part of the brain. It is located below the large cerebrum in between the two cerebral hemispheres. It also has an outer cortex made of grey matter and inner white matter. The main function of the cerebellum is to maintain the balance of the body and coordinate muscular activity.

Pons: The pons forms the floor of the brain stem. It serves as a neuronal link between the cerebral cortex and cerebellum.

Medulla oblongata: It is the lower portion of the brain stem. It is roughly triangular and is continued behind as the spinal cord. It controls the autonomic functions and nerve signals between the brain and spinal cord. It controls the activity of internal organs such as breathing (a physical process takes place through nose), peristaltic movement, etc.

Write a short note on human brain.

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