When considering the structure of the brain, there are 3 major parts,

  1. Fore brain
  2. Mid brain
  3. Hind brain

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Structure of the fore brain

When considering the structure of the forebrain, there are 3 major parts,

Hypothalamus

Hypothalamus is situated at the base of the forebrain, immediately beneath the thalamus and above the pituitary gland. It divides into several separate areas which have their own specific function. Hypothalamus is the main coordinating and control center for the autonomous nervous system. The hypothalamus connects to the pituitary gland and it is the main link between the nervous system and the endocrine system.  

Thalamus

The thalamus consists of two masses of nerve cells and fibers situated within the cerebral hemisphere just below the corpus callosum, one on each side of the 3rd ventricle.

The cerebrum

This is the largest part of the brain which consists of two cerebral hemispheres. Deep and longitudinal cleft separates hemispheres. The peripheral region of the cerebral hemisphere is known as the cerebral cortex. The cerebral cortex consists of grey matter containing thousands of millions of nerve cells including their cell bodies. White matter containing nerve fibers consists beneath the cortex. The cerebral cortex shows many infoldings called furrows of varying depth. The exposed areas of the folds are called convolutions and these are separated by sulci. These convolutions greatly increase the surface area of the cerebrum.

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When considering the structure of a hemisphere there are 4 lobes in each hemisphere.

1)Aortal

2) Parietal

3) Temporal

4) Occipital

Deep furrows mark the bodies of the lobes. Each cerebral hemisphere consists of one of the lateral ventricles filled with cerebrospinal fluid. A mass white matter called the corpus callosum connects the hemispheres deep within the brain. There are areas of grey matter, lying deep within the cerebral hemisphere basal ganglia. They act as relay stations that help to pass impulses from one neuron to the next.

Mid brain

Midbrain is the area of the brain between the cerebrum and the pons Varolii below. It consists of a group of nerve cells and nerve fibers that connect the cerebrum with owe parts of the brain and the spinal cord. The optic nerve enters the mid-brain.

Hind brain

When considering the structure of the hindbrain, there are 2 major parts,

Cerebellum

This is located at the back of the brain, under the cerebral hemisphere, behind the pons Varolii. The cerebellum is ovoid in shape while it has two hemispheres separated by a narrow median strip. Hemispheres are greatly convoluted. Grey matter forms the surface of the cerebellum and the white matter lies deeply.

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Pons varolii

The pons Varolii is situated in front of the cerebellum, below the midbrain and above the medulla oblongata. It consists mainly of white matter. The grey matter lies deeply and white matter is on the surface.

Medulla oblongata extends from the pons Varolii and continuous with the spinal cord. The white matter lies outer side while grey matter lies centrally. The medulla oblongata is one o the best part of the brain and one of the most vital.

Photo by Robina Weermeijer on Unsplash

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