The human brain is responsible for overseeing the daily operation of the human body.
The adult human brain weighs an average of 1.4 Kg, or about 2 percent of the total body weight.
Although it is 2 percent but uses 20 percent of the oxygen supply and gets 20 % of the blood flow.
If brain cells do not get oxygen for 4 to 5 minutes, they begin to die.
The human brain reaches its full size at about 6 years of age.
The adult human brain contains more than a thousand million neurons.
The brain is responsible for maintaining homeostasis.
Neurons :- It is the structural and functional unit of Central Nervous System (Brain and spinal cord)
Meninges :- Brain is wrapped in three layers of connective tissues known as the Meninges.
(i) The innermost layer, which is bound to the surface of the brain, is called piamater.
(ii) The outer layer called duramater
(iii) The arachnoid is the thin elastic, web like layer between the arachnoid and the duramater
(iv) The space which is present between the arachnoid and duramater is called subdural
space.
(v) Between the piamater and the arachnoid is a space known as sub arachnoid space filled
with Cerebrospinal fluid, which act as a shock absorber.
The human brain divisible into three parts,
(i) Forebrain or prosencephalon
(ii) Midbrain or mesencephalon
(iii) Hindbrain or rhombencephlon
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