Human Nervous System

Question 1

What are the 2 types of coordination?

Answer 1

The 2 types are:

• Nervous
• Chemical

Question 2

What is nervous coordination?

Answer 2

this is brought about by the nervous system, which is made up of the brain, spinal cord, nerves and sense organs.
ex- when you feel hungry you eat

Question 3

What is chemical coordination?

Answer 3

this type of coordination is brought about by the chemical messengers called hormones.
ex- when you see a bull on the street your instinct is to run. chemicals release extra energy in the blood to help you run

Question 4

Structural and Functional Unit of Nervous System - NEURON

Answer 4

• nervous system is made up of cells called nerve cells or neurons
• it is made up of a cyton and an axon
• it contains of a nucleus
• dendrites receive impulses from organs and transmit them to axon
• end of axon has a number of branches called axon terminals or terminal branches

Question 5

Structural and Functional Unit of Nervous System - NEURON

Answer 5

• nervous system is made up of cells called nerve cells or neurons
• it is made up of a cyton and an axon
• it contains of a nucleus
• dendrites receive impulses from organs and transmit them to axon
• end of axon has a number of branches called axon terminals or terminal branches

Question 6

What is synapse?

Answer 6

the axon terminals of a neuron lie very close to the dendrites of another. their point of contact is called synapse it is at this place where the message is transmitted .

Question 7

What are the 3 types of neurons?

Answer 7

• sensory neurons
• motor neurons
• association neurons

Question 8

Explain the 3 types of neurons

Answer 8

• SENSORY: these carry impulses from the sense organs to the spinal cord or brain
• MOTOR: these carry impulses from brain or spinal cord to the source [ muscle ]
• ASSOCIATION: these are present in the spinal cord and transmit impulses from one neuron to another

Question 9

What is a nerve? what are its 3 types?

Answer 9

a nerve is formed of a bundle of axons enclosed in a tubular medullary sheath.
its types
- sensory nerve
- motor nerve
- mixed nerve

Question 10

Explain the 3 types of nerves

Answer 10

- SENSORY: consists of sensory neuron
ex- optic nerve
- MOTOR: contains only motor neurons
ex- muscle of the eye
-MIXED: carries both, sensory and motor neurons
ex- nerve going to the tounge

Question 11

What are the 2 main systems in the human nervous system?

Answer 11

1. The central nervous system

2. The peripheral nervous system

Question 12

Explain these 2 systems: central and peripheral

Answer 12

1. This consists of the braina and spinal cord. Brain lies within the skull and the spial cord lies within the vertebral column.
2. It consists of nerves that pass to and from the central nervous system. Its 2 parts are:
   ~ somatic nervous system
   ~ autonomic nervous system

Question 13

Give a brief about our brain

Answer 13

• it is the complex and important part of our body
• on an average an adult brain weighs 1.5kg
• it is protected by a bony structure called skull or cranium
• brain is further divided into 3 membranes called meninges which are separated by the fluid floating around in our brain

Question 14

Name the 3 main parts of the brain

Answer 14

• cerebrum
• cerebellum
• medulla oblongata

Question 15

Explain cerebrum

Answer 15

• it is the largest portion of the brain
• it is divided into 2 hemispheres called the cerebral hemispheres
• each of these are hollow
• outer surface is covered with bridges and grooves to accommodate many neurons
• human cerebrum contains about 9B neurons
• this controls all the voluntary actions
  ex- intelligence , will power , consciousness

Question 16

Explain cerebellum

Answer 16

• it is smaller and is under the cerebrum
• its main function is to balance the body and coordinate muscular activities
• cerebellum implements the action that the cerebrum decides
• a drunk person cannot coordinate his movements properly as alcohol affects the cerebellum

Question 17

Explain medulla oblongata

Answer 17

• it is the lowest part
• it controls the activities of internal organs
  ex- beating of heart , breathing
• if this is seriously injured it may cause immediate death of a person

Question 18

Give a brief about spinal cord

Answer 18

it extends from the medulla through the whole backbone

Question 19

What is the spinals cords main functions

Answer 19

• control reflexes below the neck
• carry messages from skin , muscle to brain
• conduct commands from brain to muscle of the trunk limbs

Question 20

Give brief about peripheral nervous system

Answer 20

its divided into somatic and autonomic nervous system.

Question 21

Define somatic nervous system

Answer 21

• they consist of 2 types of nerves:
  ~cranial nerves which arise from the brain
  ~spinal nerves which arise from the spinal cord
• it is responsible for relaying sensations like smell , taste , etc
• and also for sending commands from central nervous system to skeletal muscles

Question 22

Define autonomic nervous system

Answer 22

• it consists of a pair of chains of ganglia
• it regulates involuntary actions and works unconsciously
  ex- blood pressure , respiratory rate
• it operates through 2 systems:
  ~ sympathetic system
  ~ parasympathetic system

Question 23

Define sympathetic system

Answer 23

• this produces immediate flight or fight responses

Question 24

What is parasympathetic system

Answer 24

• this re-establishes normal conditions

ex- if sympathetic system increases heart rate then parasympathetic will relax it