6. Nervous System

Question 1

Stimuli

Answer 1

changes in the environment to which organisms respond and react

Question 2

response

Answer 2

reaction of the organism due to the stimulus

Question 3

receptors

Answer 3

molecules that are present on the surface of cells to cause specific effect on them

Question 4

effectors

Answer 4

special organs in the bodt that bring about responses

Question 5

what are the 5 receptors in our body and where are they

Answer 5

Photo receptors - eyes
Olfactory receptors - nose
Gustatory receptors - tongue
Auditory/ Balance receptors - ears
Skin receptors

Question 6

Coordination

Answer 6

there needs to be a very good interaction between the receptors (of sense organs) and the effectors (muscles and glands) for there to be a response to the stimuli
this is known as coordination

Question 7

nervous coordination

Answer 7

controlling and coordinating the various functions of your body through nervous system is known as nervous coordination

Question 8

chemical coordination

Answer 8

controlling and coordinating body functions through hormones is known as chemical coordination

Question 9

which system carries out chemical coordination

Answer 9

endocrine system

Question 10

hormones

Answer 10

chemical substances known as hormones (chemical messengers) work inside your body

Question 11

what are the two parts of the nervous system

Answer 11

Central nervous system

Peripheral nervous system

Question 12

what is the central nervous system made of?

Answer 12

brain, spinal cord, relay neurons

Question 13

what is the CNS also called

Answer 13

Body’s command centre

Question 14

what is the peripheral nervous system made of

Answer 14

network of nerves

Question 15

what is the main function of the peripheral nervous system

Answer 15

to connect parts of the body to the central nervous system

Question 16

what is the peripheral nervous system also called

Answer 16

information highway

Question 17

what does the peripheral nervous system consist of

Answer 17

somatic nervous system (skeletal muscles, voluntary actions)

autonomic nervous system (involuntary actions)

Question 18

what are nerve cells

Answer 18

group of specialized cells which help in communication and coordination of various responses in our bodies by linking different parts of a complex network

Question 19

functions of nervous system

Answer 19

• keeps us informed of changes in our surroundings
• enables us to think, remember and reason to find solutions to our problems
• controls and harmonizes voluntary functions
• regulates involuntary functions

Question 20

set of bones around the brain

Answer 20

skull/ cranium

Question 21

bony cage which protects the spinal cord

Answer 21

vertebral column

Question 22

what controls the autonomic nervous system

Answer 22

medulla oblangata

Question 23

nerve impulse

Answer 23

electrical signal that carries information to and from the brain and travels along a nerve

Question 24

myelin sheath

Answer 24

fatty white substance which covers the axons; main purpose is insulation

Question 25

synapse

Answer 25

junction between two neurons i.e dendrites of one neuron and axon of the immediately next neuron is called synapse

Question 26

axon

Answer 26

long tube like projection arising outwards from cell body

Question 27

Cell body is also called

Answer 27

soma/cyton

Question 28

cell body consists of

Answer 28

cytoplasm and nucleus

Question 29

dendrites

Answer 29

long and thin cytoplasmic projections stretching out from the soma

Question 30

2 functions sensory neurons

Answer 30

recieve messages from receptors

carry impulses to the brain and spinal cord

Question 31

function of motor neurons

Answer 31

transmit impulses from brain and spinal cord to effectors to initiate response

Question 32

function of relay neurons/interneurons/association neurons

Answer 32

serve as links between sensory and motor neurons and conduct impulses between them

Question 33

what is the brain (2)

Answer 33

highest coordinating centre in the body

complex organ which controls thought, memory, emotion, motor skills, etc and all other processes to regulate the body

Question 34

3 statistics on the brain

Answer 34

(adult brain) weighs 1.35 kg

consumes 25% of total oxygen in body

contains 80% water

Question 35

what are the meninges

Answer 35

three membranous coverings which cover the brain

Question 36

what is the function of meninges

Answer 36

cover the brain and spine

cushion, nourish and protect the brain and spine

Question 37

cerebrospinal fluid

Answer 37

space between the meninges is filled with a special watery fluid

Question 38

what does cerebrospinal fluid do

Answer 38

collect waste material from the neurons of the brain

Question 39

three parts of the brain

Answer 39

• cerebrum
• cerebellum
• medulla oblongata

Question 40

5 points on the cerebrum

Answer 40

• anterior/front part of the brain
• divided into right and left hemispheres
• hemispheres are separated by a deep groove
• outer surface is full of fold (more space to pack in neurons)
• walls of each hemisphere have two internal regions: outer cortex and inner medulla

Question 41

what is grey matter

Answer 41

• outer cortex contains the cell bodies of the neurons and appears grey-ish
• hence, it is called grey matter

Question 42

what is white matter

Answer 42

• inner medulla contains the axons of the neuron
• appears white and hence is called white matter

Question 43

sheet of fibres that joins the two cerebral hemispheres together

Answer 43

corpus callosum

Question 44

what does corpus callosum do

Answer 44

transfers information from one hemisphere to the other