B3

Question 1

What components make up the structure of a nervous system?

Answer 1

🟡CNS(brain + spinal chord)
🟡sensory, motor, relay neurones
🟡receptors and effectors
🟡synapses

Question 2

What is a neuron?

Answer 2

A nerve cell, carrying impulses from one component to another

Question 3

Describe a sensory neurone:

Answer 3

Carries electrical impulses from receptor cells to the CNS
🟣cell body in the middle of the cell
🟣ends surrounded with dendrites (to connect neurones)
🟣axon surrounded by mycelin

Question 4

Describe a motor neurone

Answer 4

Carry’s an electrical impulse from the CNS to an dendrites
🟣cell body near dendrites
🟣ends have dendrites
🟣axon surrounded with mycelin

Question 5

What do relay neurones do?

Answer 5

Carry an impulse from a sensory neurone to a motor neurone

Question 6

What is a synapse and how does it work?

Answer 6

The gap impulse two nerve cells(neurones)
🟡electrical current turned into chemical current
🟡chemical (neurotransmitter) diffuses across the gap
🟡turned back into an electrical impulse

Question 7

What are receptors?

Answer 7

Cells that detect a stimuli, creating an electrical impulse

Question 8

What are effectors?

Answer 8

Muscles / glands that carry out the response

Question 9

Describe how the nervous system produces a co ordinated response

Answer 9

🔴Can go to many parts of the body at once (many different motor neurones at once
🔴many different sensory receptors are able to bring in the impulse at once

Question 10

Describe a reflex arc

Answer 10

Stimulus
Receptor
Sensory neuron
Spinal cord (relay neuron)
Motor neuron
Effector

Question 11

How is the reflex arc adapted to serve its function?

Answer 11

Instead of going through the whole CNS(brain + spinal chord), it only goes to spinal chord
🟣making it fast and automatic
* to protect the body from danger

Question 12

Can signals move along a neurone in any direction ?

Answer 12

No, an electrical impulse can travel in one direction only

Question 13

Describe the cornea

Answer 13

🟣transparent outer layer
🟣refracts light onto the retina

Question 14

Describe the iris

Answer 14

🟣coloured ring muscle
🟣controls how much light enter the eye

Question 15

Describe the pupil

Answer 15

Central hole allowing light to come into the eye

Question 16

Describe the lens

Answer 16

🟣transparent biconvex disk
🟣focuses light onto the retina

Question 17

Describe the retina

Answer 17

Tissue at the back of the eye, containing photoreceptors (convert tissues to electrical signals)

Question 18

Optic nerve

Answer 18

Carries impulses between the eye and the brain

Question 19

Ciliary body
What happens when it contracts?

Answer 19

🟡Muscular tissue that Alters the shape of the lens
*If it contracts it gets closer to the lens, making it fatter(short sight), this means the suspensory ligaments slack

Question 20

Suspenseful ligaments

Answer 20

🔵Ligament tissue connecting ciliary muscle to eye
* does the opposite to ciliary muscle

Question 21

Describe short sightedness and how to overcome

Answer 21

🔵eyeball is too long
🔵image focused in front of the retina
🟢concave lens in glasses

Question 22

Describe long sightedness and how to overcome

Answer 22

🔵the eyeball is too short
🔵image focussed behind the retina
🟢convex lens in glasses

Question 23

What happens to lens to focus on nearby and far objects?

Answer 23

🟣nearby, lens gets fatter , ciliary muscle contracts
🟣far away, let’s goes thinner , ciliary muscle relaxes

Question 24

Describe colourblindness and how to overcome

Answer 24

🟣inability to tell the difference between different colours die to lack/defects in receptors in retina
🟣tinted lenses

Question 25

What is the function of the brain?

Answer 25

🧠Processed all the information collected by receptors
🧠 produced a co ordinated response using all this

Question 26

What is the function of the cerebrum

Answer 26

Learning, memory, personality and conscious thought
👩🏻‍🏫👩🏻‍🎤💭🤔

Question 27

What is the function of the cerebellum?

Answer 27

Controls posture, balance
🧍‍♀️⚖️

Question 28

What is the function of the medulla?

Answer 28

Heart rate and breathing rate
❤️😮‍💨

Question 29

What is the function of the hypothalamus?

Answer 29

Regulates temperature and water balance
🌡💦

Question 30

What is the function of the pituitary?

Answer 30

Stores and releases hormones

Question 31

What are some of the difficulties in investing brain function?

Answer 31

🔴case studies are hard to obtain and interpret- not really much that we know about the brain
🔴it’s unethical to ask some patients as they are not in the right ‘state’

Question 32

What are the limitations in treating damage and disease in the brain and other parts of the nervous system?

Answer 32

🟢CNS cells do not have the ability to regenerate and repair
🟢as it is protected by the skull, it is difficult to access during surgery
🟢irreversible damage to surrounding tissue