B10

Question 1

What is Homeostatis?

Answer 1

The maintenance of a constant internal enviroment

Question 2

What do cells need to be to function?

Answer 2

They need to be homeostatis meaning they need to be optimum conditions in order to function.

Question 3

What is homeostatis needed for?

Answer 3

For enzyme action and cell function

Question 4

In the human body what does homeostatis control?

Answer 4

• Blood glucose concentration
• Body temperature
• Water levels.

Question 5

What is involved in automatic control sytems?

Answer 5

Nervous and hormonal communication

Question 6

What do Receptors do?

Answer 6

They are cells that detect the stimuli and the changes in the enviroment

Question 7

What do coordination centres do?

Answer 7

Process the information received from the receptors eg brain,spinal cord and pancreas

Question 8

What do effectors (muscle and glands )do?

Answer 8

They bring out responses which restore optimum level

Question 9

What is the nervous system?

Answer 9

The nervous system enables humans to react to the surroundings and coordinate their behaviour

Question 10

What do Receptor cells do?

Answer 10

Convert stimulus into electrical impulses.

Question 11

What do electrical impulses do?

Answer 11

Travels along the sensory neurones to the CNS

Question 12

What does the CNS do?

Answer 12

The information is processed and a response is coordinated. Resulting the electrical impulses being sent through motor neurones to effectors

Question 13

What is the order of the CNS?

Answer 13

Stimulus —> receptor —> SN —> CNS —> MN —> effector —> response

Question 14

What does the Sensory Neurone do?

Answer 14

they are neurones that Carry information as electrical impulses from the receptor to CNS

Question 15

What does the Motor Neurone do?

Answer 15

The Neurons that carry carry electrical impulses from CNS to effectors

Question 16

What are effectors?

Answer 16

All your muscles and glands which respond to nervous impulses

Question 17

What can receptors and effectors form?

Answer 17

Part of Complex organs

Question 18

What do effectors respond to?

Answer 18

They respond to nervous impulses and bring out a change

Question 19

Give an example of a stimuli? (Bird)

Answer 19

When a bird sees a cat walking towards it

Question 20

Give an example of a receptor and sensory neurone ? (Bird)

Answer 20

The receptor in birds eye gets stimulated . Sensory Neurone carrys information from receptor to CNS

Question 21

Give an example of what the CNS does?

Answer 21

The CNS sends information to the muscles (effectors) of the bird wings along with motor neurones. The muscles contract and fly away.

Question 22

What connects Neurones?

Answer 22

Synapses

Question 23

What is the connection between two neurones called?

Answer 23

Synapse

Question 24

How are nerve signals transfered?

Answer 24

Nerve signals are transfered by chemicals which diffuse across the gap.

Question 25

What happens in the next neurone?

Answer 25

The chemicals send a new electrical signal

Question 26

What helps prevent injuries?

Answer 26

Reflexes

Question 27

What are reflexes?

Answer 27

Rapid automatic responses to certain stimuli that don't involve the conscious part of the brain

Question 28

What happens if someones shines a bright light in your eye?

Answer 28

Your pupils get smaller so less light is in and your eyes dont get damaged

Question 29

What is the passage information in a reflex called?

Answer 29

Reflex arc

Question 30

What does the reflex arc go through?

Answer 30

The CNS

Question 31

What do the neurones in the reflex arc go through?

Answer 31

Spinal cord or unconscious part of the brain

Question 32

What happens when a stimuli detects receptors?

Answer 32

Impluses are sent to the sensory neurone to a relay neurone in CNS

Question 33

What do relay neurones do?

Answer 33

Connect sensory neurones to motor neurones

Question 34

What happens when the impulses reach a synapse between sensory neurone and relay neurone?

Answer 34

They trigger chemicals to be released

Question 35

What do the impulses travel along?

Answer 35

Motor neurone to the effector

Question 36

What is reaction time?

Answer 36

The time it takes to repsond to a stimuli

Question 37

What is the brain responsible for?

Answer 37

Complex behaviours

Question 38

What is the brain apart of?

Answer 38

The CNS

Question 39

What is the brain made up of?

Answer 39

Billions of interconnected neurones

Question 40

What does the brain control?

Answer 40

Everything. Eg running , sleeping , breathing

Question 41

What is the cerbal cortex?

Answer 41

Its the outer wrinkly bit and responsible for intelligence,memory and language

Question 42

What is the medulla?

Answer 42

Controls unconscious activities. eg breathing

Question 43

What is the cerebellum

Answer 43

Responsible for muscle coordination

Question 44

What are the 3 ways scientists study the brain?

Answer 44

MRI scan, studing patients with brain damage, electrically stimulating the brain

Question 45

What is an MRI scan?

Answer 45

It's a tube-like machine that can produce detailed images of the brains structure. They use it in active places of the brain

Question 46

What happens when electrically stimulating the brain?

Answer 46

It can be electrically stimulated by pushing a tiny electrode into the tissue and giving it a small zap of electricity

Question 47

What can electrical stimulation reduce?

Answer 47

Muscle tremors

Question 48

What does the Scelera do?

Answer 48

Its the supporting wall of the eye

Question 49

What's the cornea?

Answer 49

Transparent outter layer found at the front of the eye. It bends light into the eye

Question 50

Whats the iris?

Answer 50

Contains muscles that allow it to control the diameter of the pupil and therefore controls how much light eneter the eye

Question 51

What is the lens?

Answer 51

Focuses light onto the retina ( which contains receptor)

Question 52

What is the shape of the lens comtrolled by?

Answer 52

Cilliary muscles and suspensory ligaments

Question 53

What does the optic nerve do?

Answer 53

Carry receptors from retina to brain

Question 54

How does the eye focus light on the retina?

Answer 54

By changing the shape of the lens (accommodation)

Question 55

What happens when you look at close objects?

Answer 55

1) Cilliary muscles contract which slackens the suspensory ligaments 2) The lens becomes fat 3) This increases the amount of which it refracts

Question 56

What happens at distant objects?

Answer 56

1) The cilliary muscles relax which allows suspensory ligaments to pull tight 2) This makes lens go thin 3) So it refracts by a smaller amount

Question 57

What happens if the lens cannot refract?

Answer 57

The person will be short/long sighted

Question 58

Why are people long sighted?

Answer 58

- The lens is the wrong shape and doesnt refract the light enough - Eyeball is too short The image of near objects are brought into focus behind the retina

Question 59

How can you fix longsighted people?

Answer 59

Use a convex lens. This refracts light so they focus on retina

Question 60

Whats the medical term for long sightedness?

Answer 60

Hyperopia

Question 61

Why are people short sighted?

Answer 61

- The lens is the wrong shape and refracts light too much - Eyeball is too long - The image is brought in front of the retina

Question 62

How do you prevent short sightedness?

Answer 62

Use concave lens so light focuses on retina

Question 63

What is the medical term for short sightedness?

Answer 63

Myopia

Question 64

What are the alternatives for vision defects?

Answer 64

- Contact lenses - laser eye surgery - replacement lens surgery

Question 65

What are contact lenses?

Answer 65

Thin lenses that sit on the surface of your eye and are shaped to compensate for the fault in focusing

Question 66

Advantages for contact lenses?

Answer 66

- Lightweight and invisible - You can use them in sports

Question 67

Disadvantages of contact lenses?

Answer 67

- Uncomfortable - Soft lens can cause eye infection

Question 68

What is laser eye surgery?

Answer 68

A laser is used to vaporise the tissue changing the shape of the cornea.

Question 69

What does slimming it down in laser surgery do?

Answer 69

Less powerful byt improves short sight

Question 70

What does changing the shape is laser eye surgery do?

Answer 70

More powerful and improve long sight

Question 71

Disadvantage of laser eye surgery?

Answer 71

Can make eyesight worse than before And cause infection

Question 72

Whats the retina?

Answer 72

A layer of cells at the back of the eye that detect light and send signals to the brain through the optic nerve