Coordination And Response

Question 1

Stimulus

Answer 1

A change in the environment that can be sensed

Question 2

Response

Answer 2

An action caused by the effector due to the stimulus

Question 3

Receptor

Answer 3

A special structure that allows living organisms to sense the conditions of their internal or external environment

Question 4

Central nervous system

Answer 4

Consists of the Brian and spinal cord

Question 5

Effectors

Answer 5

These are the parts of the body that create a response, for example muscles or glands

Question 6

Sensory neurone

Answer 6

Nerve cell that carries messages form cells in the sense organs to the CNS

Question 7

Motor neurone

Answer 7

Carry an impulse from the CNS to the effectors

Question 8

Relay neurone

Answer 8

Sometimes called a connector, these are neurones in the central nervous shyster that transmit impulses from sensory to motor neurons

Question 9

Cell body

Answer 9

Largest part of a typical neurone; contains the nucleus and much of the cytoplasm

Question 10

Axon

Answer 10

the elongated part of a neurone, insulated by a fatty sheath, carries information along in the form of electrical impulses, sometimes called nerve fibres

Question 11

Myelin sheath

Answer 11

A fatty cover over the axon, insulates axon and speeds up impulse

Question 12

Sense organs

Answer 12

Groups of receptor cells that respond to specific stimuli: light, sound, touch, temperature and chemicals

Question 13

Synapse

Answer 13

a junction between two nerve cells, consisting of a small gap across which impulses pass by diffusion or a neurotransmitter (chemical) - impulse continues on 2nd axon.

Question 14

Neurotransmitter

Answer 14

Chemical messengers that cross the synaptic gaps between neurones, eg dopamine

Question 15

Dendrites

Answer 15

Branchlike parts of a neurone that are specialised to receive information

Question 16

Reflex arc

Answer 16

The pathway an impulse travels to initiate a super quick unconscious reaction, involves relay neurones

Question 17

Spinal cord

Answer 17

Nerves that run up and down the length of the back and transmite most messages between the body and brain

Question 18

Peripheral nervous system

Answer 18

A division of the nervous system consisting of sensory and motor nerves that are not part of the brain or spinal cord

Question 19

Ciliary muscles

Answer 19

Muscles to control the size of the lens. Contract to make the lens short and fat for near vision

Question 20

Iris

Answer 20

Controls the size of the pupil and the amount of light entering the eye. Made of circular and radial muscles.

Question 21

Córnea

Answer 21

Front part of the eye that bends the light into the eye

Question 22

Lens

Answer 22

Focuses the light onto the retina

Question 23

Fovea

Answer 23

Focus point on the retina. Area of most cones and so responsible for colour vision

Question 24

Optic nerve

Answer 24

Carries the signals form the retina to the visual cortex of the brain

Question 25

Simple reflex arc

Answer 25

Stimulus -> receptor -> sensory neurone -> relay neurone -> motor neurone -> effector -> response