Write a short note on the hindbrain.

Hint The brain is the most important organ in the human body, which controls and coordinates with the other body parts with the help of the spinal cord or spinal nerves. The brain is mainly divided into three parts and all parts have their function which is controlled by the hormone they secrete.

Complete Answer:
The hindbrain is also known as Rhombencephalon and it comprises the cerebellum, Pons Varolii, and Medulla oblongata. The cerebellum is also known as the little brain and it is also the second-largest part of the brain consisting of two cerebellar hemispheres and a central vermis. The cerebellum lies below the posterior portion of cerebral hemispheres and above the medulla. It has branched white matter surrounded by the sheath of grey matter called the cerebellar cortex. The cerebellar cortex consists of flask-shaped complex neurons called Purkinje cells. The cerebellum controls muscular activities and maintains posture and equilibrium. Pons Varolii lies above the medulla oblongata. It interconnects with two cerebellar hemispheres with the help of nerve fibres and also joins with the medulla through the brain centres. It transmits impulses between the cerebellum and medulla and then to a higher centre of the brain. The medulla oblongata is the posterior-most of the hindbrain and it interconnects the spinal cord and various parts of the brain. Most of the sensory nerve fibre and motor fibre crosses from one side to another inside the medulla. The lower end of the medulla passes into the spinal cord. It transmits a signal between the spinal cord to the cerebellum and thalamus. It regulates voluntary and involuntary movements like a heartbeat, blood pressure, breathing, swallowing, salivation, gastric secretion, urinating, coughing, etc.

Note: The brainstem is the collection of the midbrain, pons Varolii and medulla oblongata. The fourth ventricle of the brain lies between the brainstem and cerebellum and connected with the third ventricle through the cerebral aqueduct or aqueduct of Sylvius.