Cells and control (2) Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What does the nervous system do?

A

protects organisms from harm by responding to changes in the environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does the nervous system work?

A

Coordinating the communication between different parts of the organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the nervous system made up of?

A

The brain, the spinal cord, neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are effectors?

A

Muscles or glands that act in response to a change in the internal or external environment,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why is the spinal cord important?

A

it, like the brain, coordinates the response of effectors to changes in the environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do neurones (nerve cells) do?

A

carry electrical impulses between receptors, the CNS and effectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are synapses?

A

gaps between neurones in which the nerve impulses must travel across

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do axons do?

A

Carry electrical impulses away from the cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do dendrites do?

A

Carry electrical impulses towards the cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are axons covered in?

A

a layer called myelin sheath which insulates the neuron.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name three reflex actions

A

Blinking, dropping hot objects, sneezing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does the nervous system respond to stimuli

A

via a reflex arc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the different parts of a reflex arc?

A

stimulus, receptor, neurones, effector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Whats a stimulus?

A

any change in the environment to which the body needs to respond; detected by a receptor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Whats a receptpr?

A

they detect a change in the environment and initiate a signaling process all over the body which is then picked up by a neurone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the three types of neurone?

A

sensory (carries signals via electrical impulse), relay (relays the electrical impulse from the sensory neurone to the right motor neuron), Motor (carries the electrical impulse to an effector)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

whats a response

A

an action that helps the organism to avoid a dangerous situation.

18
Q

what is the brain

A

an organ that controls conscious and unconscious thoughts to keep an organism alive.

19
Q

what are the three main parts of the brain?

A

cerebral hemispheres (responsible for all conscious thought), Medulla oblongata (responsible for unconscious activities) and the cerebellum (responsible for muscle coordination)

20
Q

How does CT scanning work?

A

Many X-Rays are taken of the brain and a 3D image is then built. Brian tumors show as white blotches.

21
Q

How do PET scans work?

A

using radioactive glucose, the amount of glucose being used by each part of the brain can be monitored. an image of brains activity is then made from this.

22
Q

what happens if the spinal cord is cut

A

electrical impulses can no longer be sent to the brain. wires can partially re connect it, but it isn’t very effective.

23
Q

how do you treat neurone damage

A

you can’t neurone damage is permanent and irreversible. they cant be replaced unlike other cells in the body.

24
Q

what is a brain tumor?

A

lumps of dividing cancer cells, can block bloodflow to other parts of the brain

25
Q

how can brain tumors be treated?

A

chemotherapy, radiotherapy or surgery.

26
Q

what is the cornea

A

the frontal part of the eye that refracts light

27
Q

what is the retina

A

full of receptor cells which are sensitive to brightness and colour of light.

28
Q

what’s the sclera?

A

the white of the eye which is the opaque, protective outer layer

29
Q

what is the optic nerve

A

the thing that transmits visual information from the retina to the brain.

30
Q

what is the pupil

A

a hole in the centre of the iris, through which light passes to get to the retina.

31
Q

what is the iris

A

controls the pupil diameter, therefore, the quantity of light reaching the retina.

32
Q

what are the ciliary muscles

A

a ring of smooth muscles that can change the shape of the lens.

33
Q

what are the suspensory ligaments

A

a ring of fibres that connect the ciliary muscles to the lens.

34
Q

what is accommodation

A

the process in which the lens changes shape to focus on an object as the distance changes.

35
Q

what are three ways to treat eye defects

A

glasses fitted with lenses that refract light (contact lenses and laser eye surgery too), synthetic lenses (for cataracts).

36
Q

when does short sightedness happen?

A

when rays of light focus in front of the retina

37
Q

when does long sightedness happen

A

when rays of light focus behind the retina

38
Q

how is colour blindness caused?

A

it’s inherited and caused by the defects in the cone cells.

39
Q

what do cone and rod cells do

A

detect light colour and light intensity respectively

40
Q

what causes cataracts

A

build up of protein in the lens that makes the pupil cloudy.