Nervous System + The Eye

Question 0

What is a stimulus?

Answer 0

A change in internal or external environment or surroundings

Question 1

What do we need for a coordinated response?

Answer 1

A stimulus and a response

Question 2

What is a response?

Answer 2

A reaction to the change

Question 3

State the order that the coordinated response happens in (5)

Answer 3

STIMULUS 
RECEPTOR
COORDINATION
EFFECTOR
RESPONSE

Question 4

What does a response organ do?

Answer 4

It detects a stimulus

Question 5

What does an effector organ do?

Answer 5

Carries out the response

Question 6

What does a receptor do?

Answer 6

Detects the change in the environment and changes its energy form into electrical energy, which can then be sent via the nervous system

Question 7

Give two examples of a receptor and what energy it converts into nerve impulses

Answer 7

Eye coverts light energy into nerve impulses

Ear converts sound energy into nerve impulses

Question 8

What is Transduction?

Answer 8

The changing of energy from one form to the other

Question 9

What do motor nerves do?

Answer 9

Carry information FROM the central nervous system (CNS)

Question 10

What do sensory nerves do?

Answer 10

Carry information TO the Central Nervous System (CNS)

Question 11

What is the central nervous system?

Answer 11

The brain and spinal cord

Question 12

What is the peripheral nervous system?

Answer 12

Sensory nerves and motor nerves

Question 13

What is the function of the nervous system?

Answer 13

To carry messages to and from the brain to all parts of the body

Question 14

What are the parts of a neuron?

Answer 14

Nerve cell body
Cytoplasm
Nucleus 
Dendrites
Axon

Question 15

What is the axon and what does it do?

Answer 15

It is long and fibrous and connects the cell body to parts of the body (eg muscles)

Question 16

What do the dendrites do?

Answer 16

Connect various nerve cell bodies together

Question 17

What do motor neurons do?

Answer 17

Transmit impulses to muscles enabling a response

Question 18

What do the sensory neurons do?

Answer 18

Impulses from the receptors pass along then until they reach the CNS (brain or spinal cord)

Question 19

Where is the cell body found on a motor neuron?

Answer 19

At the start

Question 20

Where is the cell body found in a sensory neuron?

Answer 20

In the middle

Question 21

What does the cell body do on a sensory neuron?

Answer 21

It decides where the impulses go (brain or spinal cord)

Question 22

What does the axon do on a sensory neuron?

Answer 22

Carries out decision

Question 23

Give an example of a stimulus

Answer 23

Heat, pain, sound or anything else that makes sense lol

Question 24

What is reaction time?

Answer 24

The interval time between the presentation of a stimulus and the start of the muscular response

Question 25

What are stimulants? Give an example

Answer 25

Drugs that increase brain activity eg nicotine caffeine ecstasy

Question 26

What are depressants? Give an example

Answer 26

Drugs that slow down brain activity eg alcohol solvents temazepan

Question 27

What is a synapse?

Answer 27

The gap between the axon of a sensory neuron and the sense ok of a motor neuron.

Question 28

How do synapses work?

Answer 28

Electrical impulse travels along axon Triggers nerve ending of neuron to release neurotransmitters (chemicals) These chemicals diffuse across synapse and bind with receptor molecules on the membrane of next neuron The receptor molecules bind only to the specific chemicals released from first neuron This stimulates second neuron to transmit the electrical impulse

Question 29

How do synapses affect your reaction time?

Answer 29

Make it slower because it takes time for chemicals to diffuse across synapse

Question 30

What is a reflex action?

Answer 30

A rapid, involuntary response to a stimulus

Question 31

What is the purpose of a reflex action?

Answer 31

To protect the body

Question 32

What does an involuntary response mean?

Answer 32

That it is not started by impulses from the brain

Question 33

Give 3 examples of reflexes

Answer 33

Startle reflex Withdrawal reflex Iris reflex

Question 34

What does the grey matter in the spinal cord contain?

Answer 34

Mainly cell bodies (intellectual part)

Question 35

What does the white matter in the spinal cord contain?

Answer 35

Axons and fatty myelin sheath

Question 36

Function of cornea

Answer 36

It refracts the light and protects the eye

Question 37

Function of iris

Answer 37

Controls how much light enters the pupil

Question 38

How does the iris work

Answer 38

It changes the shape of the pupils using circular and radial muscles

Question 39

What characteristic to circular and radial muscles have?

Answer 39

They are antagonistic

Question 40

What does the iris do in bright light?

Answer 40

Circular muscles contract Radial muscles relax Pupils constrict

Question 41

What does the iris do in dim light?

Answer 41

Circular muscles relax Radial muscles contract Pupils dilate

Question 42

Function of the lens

Answer 42

Focuses light onto the retina

Question 43

Function of the ciliary muscles

Answer 43

Help change the shape of the lens in accommodation

Question 44

What is the process called that controls how your eyes focus

Answer 44

Accommodation

Question 45

What is accommodation?

Answer 45

When the lens changes shape to cause more or less refraction depending on the distance of the object controlled by the ciliary muscles and suspensory ligaments

Question 46

What happens in accommodation with a distant object

Answer 46

Ciliary muscles relax Suspensory ligaments tighten Lens is pulled thin (to allow more refraction)

Question 47

What happens in accommodation with a close object

Answer 47

Ciliary muscles contract Suspensory ligaments slacken Lens becomes fatter (to allow less refraction)

Question 48

Function of the optic nerve

Answer 48

The bundle of sensory neutrons that carry impulses to the brain

Question 49

Function of the retina

Answer 49

Layer of tissue at the back of the eye that contains photoreceptors cells called rods and cones

Question 50

When do rod cells work and what colour to they see in

Answer 50

In dim light and can only see in black and white

Question 51

When do cone cells work and what colour do they see in

Answer 51

In bright light and detect the colours red, green and blue

Question 52

Function of the fovea

Answer 52

Area of the retina with the highest concentration of cone cells that provide sharp vision

Question 53

Function of the aqueous humour

Answer 53

Maintains the pressure in the eye and nourishes the cornea

Question 54

Function of the vitreous humour

Answer 54

Maintains the shape of the eye and attaches to the retina

Question 55

Function of the sclera

Answer 55

Tough outer layer that extra-ocular muscles can attach to

Question 56

Function of the pupil

Answer 56

Hole in the centre of the eye that lets light in

Question 57

What makes up a neurone?

Answer 57

cell body Dendrites Axon

Question 58

What is the job of sensory neurones

Answer 58

Carry information from the sense organs to the CNS and detect changes outside the body

Question 59

What is the job of motor neurones?

Answer 59

To carry instructions from the CNS to the effector organs (muscles and glands)

Question 60

What is the job of neurones?

Answer 60

To carry electrical impulses

Question 61

What controls the amount of light entering your eye?

Answer 61

The pupil reflex

Question 62

What do chemical transmitters do?

Answer 62

They diffuse across the synapse to reach the next neurone

Question 63

What does a relay Neuron do?

Answer 63

Pass messages between neurons in the CNS