Question

full human brain notes

Answer 1

1. The human brain is the command center for the human nervous system. It receives input from the sensory organs and sends output to the muscles. The human brain has the same basic structure as other mammal brains, but is larger in relation to body size than any other brains.
2. The human brain is the largest brain of all vertebrates relative to body size
3. It weighs about 3.3 lbs. (1.5 kilograms)
4. The brain makes up about 2 percent of a human's body weight
5. The cerebrum makes up 85 percent of the brain's weight
6. It contains about 86 billion nerve cells (neurons) — the "gray matter".

Answer 2

Human Brain

→ Brain is the main coordinating centre of the body. It has three major parts:

(i) Fore-brain
(ii) Mid-brain
(iii) Hind-brain



Fore-brain

→ It is the most complex or specialised part of the brain. It consists of cerebrum.

→ Functions of Fore-brain:

(i) Thinking part of the brain.
(ii) Control the voluntary actions.
(iii)Store information (Memory).
(iv) Receives sensory impulses from various parts of the body and integrate it.
(v) Centre associated with hunger.

Mid-brain

→ Controls involuntary actions such as change in pupil size and reflex movements of head, neck and trunk.

Hind-brain

It has three parts:

(i) Cerebellum : Controls posture and balance. Precision of voluntary actions. Example: picking pen.

(ii) Medulla : Controls involuntary actions. Example: blood pressure, salivation, vomiting.

(iii) Pons : Involuntary actions, regulation of respiration.

Protection of Brain and Spinal Cord

→ Protection of Brain: Brain is protected by a fluid filled balloon which acts as shock absorber and is enclosed in cranium (skull or brain box).

→ Protection of Spinal Cord: Spinal cord is enclosed in vertebral column.