(i) It receives and analyzes feelings.
(ii) It controls the power of speech.
(iii) It governs intellect, will power, inventive power, thinking etc.
(iv) It acts as a regulator of instincts.
(v) It controls the voluntary muscle activity of the body.

The forebrain consists of two large, coiled and grooved cerebral hemispheres. The two cerebral hemispheres are collectively called the cerebrum. It is the largest part of the brain (80% of brain weight). The cerebrum has two layers. The outer one is called the cerebral cortex (3 cm thick) and the inner one is called the cerebral medulla. The cerebral cortex is composed of gray matter and the cerebral medulla is composed of white matter. The cerebral hemispheres are connected by a bundle of nerves called the corpus callosum. Its surface is folded to create high and low areas. The higher area is called the gyrus and the lower area is called the sulcus.
A few folds deepen to form 3 fissures (central, parieto-occipital, lateral). Each cerebral hemisphere is divided into 5 lobes (frontal lobe, parietal lobe, occipital lobe, temporal lobe and limbic lobe).

The front of the brain is called the forebrain. It consists of three parts. namely-
1. Cerebrum: The forebrain consists of two large, coiled and grooved cerebral hemispheres. The two cerebral hemispheres are collectively called the cerebrum. It is the largest part of the brain (80% of brain weight). The cerebrum has two layers. The outer one is called the cerebral cortex (3 cm thick) and the inner one is called the cerebral medulla. The cerebral cortex is composed of gray matter and the cerebral medulla is composed of white matter. The cerebral hemispheres are connected by a bundle of nerves called the corpus callosum. Its surface is folded to create high and low areas. The higher area is called the gyrus and the lower area is called the sulcus.
A few folds deepen to form 3 fissures (central, parieto-occipital, lateral). Each cerebral hemisphere is divided into 5 lobes (frontal lobe, parietal lobe, occipital lobe, temporal lobe and limbic lobe).
Functions of the cerebrum
(i) It receives and analyzes feelings.
(ii) It controls the power of speech.
(iii) It governs intellect, will power, inventive power, thinking etc.
(iv) It acts as a regulator of instincts.
(v) It controls the voluntary muscle activity of the body.
2. Thalamus: Two oval-shaped regions located in the cerebral medulla are called thalamus. It is made up of gray matter. Each thalamus is accompanied by a pinna basal ganglia. The two thalamus are connected by a junction. The length of the thalamus is 4 cm. Each thalamus contains 1 oval ganglion.
Function of the thalamus
(i) It acts as a center for sensation of pressure, touch, pain etc.
(ii) It reveals human personality and social behavior.
(iii) It wakes up the sleeping person suddenly and alerts them to the environment.
3. Hypothalamus: A dozen separate regions below the thalamus are collectively called the hypothalamus. It is made up of gray matter. The hypothalamus is connected to the pituitary gland by a narrow part.
Functions of the hypothalamus
(i) It acts as a center of the autonomic nervous system.
(ii) acts as the center of hunger, thirst, sweat, sleep, anger, suffering, hatred, love, anxiety etc.
(iii) It regulates body heat.
(iv) It secretes ADH.
(v) It secretes two types of neurohormones namely vasopressin and oxytocin.
(vi) It regulates tropic hormone secretion with the help of neurohormones.

The swollen, large and complex part of the central nervous system at the tip of the mesentery is called the brain or encephalon. It is located in the crown. British anatomist Sir Charles Sherrington called it the great raveled knot. Male brain volume is about 1500 cubic cm, female about 1300 cubic cm and average weight is about 1.36 kg. It contains about 100 billion or 1000 billion neurons and 100 billion neurons. The brain consists of three lobes. That is, the brain is divided into three main parts. Procencephalon, Mesencephalon and Rhombencephalon.

The swollen, large and complex part of the central nervous system at the tip of the mesentery is called the brain or encephalon. It is located in the crown. British anatomist Sir Charles Sherrington called it the great raveled knot. Male brain volume is about 1500 cubic cm, female about 1300 cubic cm and average weight is about 1.36 kg. It contains about 100 billion or 1000 billion neurons and 100 billion neurons. The brain consists of three lobes. That is, the brain is divided into three main parts. Procencephalon, Mesencephalon and Rhombencephalon.

Prosencephalon
The front of the brain is called the forebrain. It consists of three parts. namely-
1. Cerebrum: The forebrain consists of two large, coiled and grooved cerebral hemispheres. The two cerebral hemispheres are collectively called the cerebrum. It is the largest part of the brain (80% of brain weight). The cerebrum has two layers. The outer one is called the cerebral cortex (3 cm thick) and the inner one is called the cerebral medulla. The cerebral cortex is composed of gray matter and the cerebral medulla is composed of white matter. The cerebral hemispheres are connected by a bundle of nerves called the corpus callosum. Its surface is folded to create high and low areas. The higher area is called the gyrus and the lower area is called the sulcus.
A few folds deepen to form 3 fissures (central, parieto-occipital, lateral). Each cerebral hemisphere is divided into 5 lobes (frontal lobe, parietal lobe, occipital lobe, temporal lobe and limbic lobe).
Functions of the cerebrum
(i) It receives and analyzes feelings.
(ii) It controls the power of speech.
(iii) It governs intellect, will power, inventive power, thinking etc.
(iv) It acts as a regulator of instincts.
(v) It controls the voluntary muscle activity of the body.
2. Thalamus: Two oval-shaped regions located in the cerebral medulla are called thalamus. It is made up of gray matter. Each thalamus is accompanied by a pinna basal ganglia. The two thalamus are connected by a junction. The length of the thalamus is 4 cm. Each thalamus contains 1 oval ganglion.
Function of the thalamus
(i) It acts as a center for sensation of pressure, touch, pain etc.
(ii) It reveals human personality and social behavior.
(iii) It wakes up the sleeping person suddenly and alerts them to the environment.
3. Hypothalamus: A dozen separate regions below the thalamus are collectively called the hypothalamus. It is made up of gray matter. The hypothalamus is connected to the pituitary gland by a narrow part.
Functions of the hypothalamus
(i) It acts as a center of the autonomic nervous system.
(ii) acts as the center of hunger, thirst, sweat, sleep, anger, suffering, hatred, love, anxiety etc.
(iii) It regulates body heat.
(iv) It secretes ADH.
(v) It secretes two types of neurohormones namely vasopressin and oxytocin.
(vi) It regulates tropic hormone secretion with the help of neurohormones.

Mesencephalon
The small and compact area between the hypothalamus and the cerebellum is called the midbrain or mesencephalon. The midbrain consists of two spherical parts on the dorsal side and two cylindrical parts on the dorsal side. It consists of three parts. namely-
1. Corpora quadrigemina: The two spherical parts on the surface are called corpora quadrigemina. It is divided transversely to form four segments.
2. Cerebral peduncle: Two cylindrical parts on the lateral side are called cerebral peduncle.
3. Cerebral Aqueduct: The fluid-filled narrow tube in the midbrain is called cerebral aqueduct. It connects the 3rd and 4th ventricles.
Functions of the Mesencephalon
(i) Maintains connections between forebrain and hindbrain.
(ii) It combines visual and auditory information.
(iii) It generates reports.

Rhombencephalon
The posterior part of the brain is called the hindbrain. It consists of 3 parts. namely-
1. Cerebellum: Two equal hemispheres coiled under the cerebral hemispheres are called cerebellum. The hemispheres are connected by two vermis. It is the largest part of the hindbrain. Its outer part is made up of gray matter and the inner part is made up of white matter. Its average weight is about 150 grams.
Functions of the cerebellum
(i) It controls muscle tension of voluntary muscles.
(ii) Maintains body balance and posture.
(iii) It determines the direction of movement.
2. Pons: The thick band on the opposite side of the cerebellum is called the pons. It lies above the medulla oblongata.
Pons’ work
(i) It acts as a relay station between the nervous system and the brain.
(ii) It regulates the rate of respiration.
(iii) It coordinates muscle activity.
(iv) 5th-8th carotid nerves arising from the pons perform various functions of the body.
3. Medulla oblongata: The pyramidal shaped part located below the pons is called the medulla oblongata. Its length is about 3 cm, width 2 cm and thickness 1.2 cm.
Functions of the medulla oblongata
(i) It acts as a control center for respiration, digestion, constriction of blood vessels, secretion of saliva, heartbeat etc.
(ii) regulates blood pressure, defecation, alimentary canal peristalsis etc. (RRAR) Protects the connection between the brain and the nervous system.
(iii) It gives rise to the 9th, 10th and 11th carotid nerves and controls various functions.

1. Protects the central nervous system from mechanical injury.
2. Protects the central nervous system from microbial attack.
3. It keeps the brain afloat and reduces weight.
4. Provides nutrients to the central nervous system.
5. Discharges waste through gaseous materials.

The ventricles, central canal and sub-arachnoid space are filled with colorless and alkaline fluid called Cerebro Spinal Fluid (CSF). It is more like plasma juice. It contains less amount of protein, amino acid, cholesterol etc. An adult’s brain contains 150 milliliters of CSF.

The ventricles, central canal and sub-arachnoid space are filled with colorless and alkaline fluid called Cerebro Spinal Fluid (CSF). It is more like plasma juice. It contains less amount of protein, amino acid, cholesterol etc. An adult’s brain contains 150 milliliters of CSF.
Importance of cerebrospinal fluid
1. Protects the central nervous system from mechanical injury.
2. Protects the central nervous system from microbial attack.
3. It keeps the brain afloat and reduces weight.
4. Provides nutrients to the central nervous system.
5. Discharges waste through gaseous materials.

1. Sudden high fever.
2. There is a headache.
3. Nausea occurs.
4. Can’t tolerate light and sound.
5. The patient suffers from ambivalence.
6. Insomnia occurs.
7. Nerve conduction is blocked.
8. Meninges are damaged.

Meningitis is a disease that occurs when the meninges are infected by bacteria. Meninges is most commonly caused by bacteria called Neisseria meningitidis. The disease later became fatal. If the meningitis is caused by a virus it is called viral meningitis and if it is caused by bacteria it is called bacterial meningitis.