SEE | Biology | Unit-2: Human nervous and Glandulary system
The external substance which can change morphology and physiology of organism is called stimulus.
- Pressure/ touch
- Flow of wind
- Chemicals, etc.
The change seem in organism is called response/ reaction.
- when we touch leaves of mimosa pundica, all the leaves are collapsed for sometimes.
Collapse leaves: Reaction/ response
- Mole comes out from hole in night.
Comes out from hole: Response/ Reaction
- Ant go towards sugar:
Movement towards sugar: Response/ reaction.
3. Nervous system:
The system composed by nervous tissure to control and co-ordinate all parts of body is called Nervous system.
It has three types:
- Central Nervous system (CNS)
- Autonomous Nervous system (ANS)
- Peripheral Nervous system (PNS)
4. Central Nervous system (CNS):
The major part of CNS is (a) Brain and (b) spinal cord.
Brain is the main part of central nervous system which control memory, decesion power, thinking, hearing, laughing, vision, heart beat movement of body, etc. It controls function of all parts of body.
Its major parts are:
- Medulla oblongate, etc.
|1. Cerebrum||It covers 80% part of brain and called fore brain or large brain. It is divided into two hemisphere by deep tissue.
|2. Cerebellum||It is a small brain. It is a lemon shaped semicircular structure present behind posterior end of cerebrum.
|3. Mid-brain||The mind brain is a part of brain present between cerebellum and pons-veroli.
The acts as a relay station between cerebellum and pons-veroli.
|4. Pons veroli||It is located between mid-brain and medulla oblongate. It works as relay station for impules.|
|5. Medulla oblongate||It is a posterior end of brain.
The spinal cord is started from here.
6. Spinal cord.
a. Definition:- The spinal cord is the nerve tissue dedicate for reffex action and it is an extension of medulla oblongata.
b. Composition:- It is composed by white grey matter. If is originated from medulla oblongata and passes through nerval canal of vertebra column. It is a cylinederical structure gradually becoming thin. It is protected by vertebral column.
- It controls relax action
- It is a transmission station between brain and all the parts of body.
7. Some technical terms:-
a. Meanings:- It is an outer protective cover of brain.
It is a three – layered structure. The layers are:
- Duramater: Outer
- Arachnoid: Middle
- Diamater: Inner connected with brain, etc.
b. Cerebro spinal fluid:- It is a shoch absorbed fluid filled between arachnoid and perimeter.
c. Cranium:- The bony box of skull in which brain is enclosed is called cranium.
d. Cranial nerve:- The nerve originated from brain is called craniul nerve. It is 12 pair in number.
e. Spinal nerve:- The nerves originated from spinal cord is called – spinal nerve. It is 31 pair in number.
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