Nervous System Pg(1-3)

Question 1

What is need of nervous system.

Answer 1

1.keeps us informed
2.enables us remember,to think,and to reason
3.controls and hormonises all voluntary muscular activities
4.regulates involuntary activities

Question 2

What is the another name of neuron?

Answer 2

Nerve cells

Question 3

Nervous system consist of______ ,______,______and_____

Answer 3

Spinal cord,brain,sense receptors and a whole lot of nerves

Question 4

The brain and spinal cord is made up of _________

Answer 4

Neurons or nerve cells

Question 5

What is the three main parts of a neuron?

Answer 5

1.cell body
2.dendrites
3.axon

Question 6

The myelin sheath shows gaps throughout the length which are called____________

Answer 6

Nodes of ranvier

Question 7

Some axons have side branches what are the branchesh called?

Answer 7

Collaterals

Question 8

What are the gaps in axon terminal called__________

Answer 8

Synaptic clefts

Question 9

What is stimulus? Give an example

Answer 9

An agent ir a sudden change if the external or internal environment that results in a change in an organism or any of its body part
Ex-light,sound,heat,pain,hunger

Question 10

Name the following:
1.the change in an organism resulting due to stimulus.
2. A wave of irritability

Answer 10

1.response
2.impulse

Question 11

What is receptors?

Answer 11

The specialised epithelial cells which, on receiving the stimulus,set up waves of impulse towards the central nervous system.

Question 12

What is a effector?

Answer 12

Muscle or gland which,on receiving the impulse from brain or spinal cord,contract or secrete substance

Question 13

What is neurotranmitter?

Answer 13

The end portions of axon store’s some chemical which is called neurotransmitter

Question 14

Define synapse.

Answer 14

Synapse is the point of contact between the terminal branch of the axon of a neuron with the dendrites of another neuron seprated by a fine gap.

Question 15

As the impulse reaches the terminal end of a axon ___________chemical is released

Answer 15

Acetycholine

Question 16

What are the three types of neuron?

Answer 16

1. Sensory neurons
   2.motor neurons
   3.association neurons

Question 17

Define sensory neurons.

Answer 17

Sensory neurons convey the impulse from receptors to main nervous system

Question 18

Define motor neurons.

Answer 18

It carry the impulse from main nervous system to an effector

Question 19

Define association neurons.

Answer 19

It connects the sensory and motor neuron

Question 20

Where is association neuron located?

Answer 20

Located in brain and spinal cord

Question 21

Define nerves.

Answer 21

Nerve is a bundle of nerve fibres of seprate neurons enclosed in a tubular sheath

Question 22

The___________sheath of axon acts lika an insulation and prevents mixing of impulse in adjacent axon.

Answer 22

Myelin

Question 23

What are the three kinds of nerves?

Answer 23

1.sensory nerves
2.motor nerves
3.mixed nerves

Question 24

The structural and functional unit of nervous system.

Answer 24

Neurons or nerve cells

Question 25

Define sensory nerves.

Answer 25

It contains only sensory fibres brining impulses from the receptors to the brain or spinal cord

Question 26

Define motor nerves.

Answer 26

It contains only motor fibres carrying impulses from brain or spinal cord to effector organs to bring them into actions.

Question 27

Give an example of sensory nerves.

Answer 27

Ex-optic nerve arising from the eye and ending in the brain

Question 28

Give an example of motor neuron.

Answer 28

Ex-a nerve arising from brain and supplying the muscles of the eyeball for rotating the eye.

Question 29

Long thread like part of the nerve cells.

Answer 29

Dendrites.

Question 30

A nerve is made up of___________

Answer 30

Bundle of axons