Homeostatasis And Responce - Nervous System

Question 1

What is Homeostasis

Answer 1

Regulation of internal conditions to maintain a stable environment, in response to internal and external changes

Question 2

What are control systems

Answer 2

Both nervous and hormonal communication systems that regulate internal environment

All contain 3 components: receptors, coordination centres and effectors

Question 3

What is a stimulus

Answer 3

A change in the environment you need to respond to

Question 4

What do receptors do

Answer 4

They detect the stimulus when the level of somthing is too high or low and send this info to the coordination centre.

Question 5

What do effectors do

Answer 5

Respond the conteract the change, bringing levels back to the optimum

Question 6

What is the nervous system made of and why is it important

Answer 6

Neurones and allows you to react to your surroundings

Question 7

Give some examples of receptors

Answer 7

Taste receptors on the tounge
Sound receptors in the ear
Light…
Smell..

Question 8

What is the cns and what does it do

Answer 8

Brain and spinal cord
It’s where reflexes and actions are coordinated
Connected to the body via sensory neurones and motor neurones.

Question 9

What are effectors

Answer 9

Muscles wich contact

Glands wich secreate hormones

Question 10

What type of nurone carrys electrical impulses through the cns

Answer 10

Relay neurons

Question 11

What is a synapse and how do they work

Answer 11

The connection between 2 neurones. The signal is transferred by chemicals wich diffuse across the gap. Theses chemicals set off a new electrical signal in the next neutrone.

Question 12

What are reflexes

Answer 12

Fast automatic responses to certain stimuli that bypass your brain completely.

Question 13

What is the passage of information called from the receptor to effector

Answer 13

Reflex arc

Question 14

Cerebral cortex

Answer 14

Outer layer of brain.

Responsible for consciousness, intelligence, memory and language

Question 15

Medulla

Answer 15

Base of the brain, top of spinal cord

Controls unconscious activitys

Question 16

Cerebellum

Answer 16

Back of the brain

Muscle coordination

Question 17

How do neuroscientist study patients with brain damage

Answer 17

The effect on the penitent after a certain part if the brain is damaged can tell you what that part of the brain does

Question 18

How do neuroscientist study the brain through electrical stimulation

Answer 18

Pushing a tiny electrode into the tissue and giving it a small zap if electricity. Observing what stimulating certain parts of the brain does gives you an idea of what those parts do

Question 19

MRI scans

Answer 19

Magnetic resonance imaging is a tube machine that provides a detailed picture of the brain. Can use it to find wich area of the brain are active when people are doing different things

Question 20

Why is treating the brain dangerous

Answer 20

Its complex, delicate so can cause physical damage to the brain or increased problems with brain functions

Question 21

What is the sclera

Answer 21

Tough supporting wall of eye

Question 22

What is the cornea

Answer 22

Transparent outer layer at front of eye

It retracts light into the eye

Question 23

What is the pupil

Answer 23

Hole in centre of the eye through wich light enters

Question 24

What is the iris

Answer 24

Contains musles that control diameter of the pupil

Question 25

What is the retina

Answer 25

Layer at back of eye that contains receptor cells. One sensitive to light intensity and the other to colour

Question 26

What is the lens

Answer 26

Focuses the light onto the retina

Question 27

What is the optic nearve

Answer 27

Carrie's implises from the receptors on the retina to the brain

Question 28

What does the iris do when light intensity increases

Answer 28

The circular muscles contact and the radial musles relax

Question 29

What is accommodation

Answer 29

The reflex which gives you the ability to focus on near and distance objects. The eye focuses light on the retina by changing the shape of the lens

Question 30

What happens if you looks at a close by object

Answer 30

Ciliary musles contract Suspensory ligaments relax This increases the amount the light refracts so the lens is fatter. When looking at distant objects the lens go thin and less curved

Question 31

When does long sightedness (hyperopia) occur, what is it and how can it be fixed

Answer 31

Unable to focus on near objects Happens when lens doesn't bend the light enough Or the eyeball is to short The image is brought into focus behind the retina Convex lens to bend light outwards

Question 32

What is myopia when does it occur and how can it be fixed

Answer 32

Inability to focus on far away objects When lens reflects light too much or eyeball is too long Image brought into to focus in front of retina Concave lens wich bends inwards

Question 33

What are contact lenses

Answer 33

Thin lenses that sit on surface of eye Lightweight and almost invisible More convenient than glasses Soft lenses are more comfortable but carry a higher risk of infection

Question 34

What is lazer eye surgery

Answer 34

Laser used to vaporized tissue, changing the shape of the cornea. Thinning it down can make it less powerful and improve short sight Risk of complications such as infections or the eye reacting

Question 35

What is replacement lens surgery

Answer 35

A lens made of clear plastic is put in. Treats long sightedness Higher risk than laser eye surgery eg possible damage to retina

Question 36

How does the body detect chang in temperature

Answer 36

Receptors in thermorengulatory centre are sensitive to temp of blood Receptors in skin send info about skin temps via nervous impulses

Question 37

How di we respond to a change in temperature

Answer 37

Impules are send the thermoregulatory centre wich acts as the coordination centre. It triggers effectors automatically. The effectors produce a response

Question 38

What are some responses to body temp getting too high

Answer 38

Hairs in skin lie flat so their isn't an insulating layer Sweat is produced by glands. When it evaporates off the skin it transfers energy to the environment. Vasodilation gets the capillaries wider so more blood flows closer to the surface of the skin.

Question 39

What are some responses to a drop in body temperature

Answer 39

Hairs on skin stand up creating an insulating layer No sweat Vacoconstriction Shivering to create respiration wich transfers energy to warm body