Year 10 The Nervous System

Question 1

Nervous system

Answer 1

Electrical impulses along neurones (nerve cells)

Question 2

Endocrine system

Answer 2

Hormones (chemical messages) via the blood

Question 3

What are the two parts structurally

Answer 3

Central nervous system inc. brain and spinal cord

Peripheral nervous system inc. all other nerves e.g ulna nerve in arm and femoral nerve in leg

Question 4

What’s a stimulus

Answer 4

A change in the environment which causes a response in the body that are five sense organs that can detect stimuli

Question 5

Ears: receptors for and stimuli

Answer 5

Sound/balance in cochlea

Sound and balance

Question 6

Eyes: receptors for and stimuli

Answer 6

Rods and cones in retina

Light

Question 7

Skin: receptors for and stimuli

Answer 7

Temperature pressure and pain

Temperature and pressure

Question 8

Nose: receptors for and stimuli

Answer 8

Olfactory receptors

Chemicals

Question 9

Tongue: receptors for and stimuli

Answer 9

Found on taste buds

Chemicals

Question 10

What’s a sense organ

Answer 10

Made up of a cluster of receptor cells which are sensitive to a specific stimuli

Question 11

Oder of the nervous system

Answer 11

Stimulus —> receptor —> sensory neurone —> CNS —> motor neurone —> effector —> response

Question 12

Stimulus

Answer 12

A change in the environment which causes a response in the body

Question 13

Receptor

Answer 13

Any changes (stimuli) picked up by cells called receptors. Usually found clustered together in sense organs

Question 14

Sensory neuron

Answer 14

Once sensory receptor detects a stimulus the info sent is chemical impulses passes along cells called neurones usually in bundles of thousands called nerves

Question 15

Central nervous system

Answer 15

Impulses travel along neuron until it reaches CNS the cells which carry impulses from sensory organs to CNS Are called sensory neurons

Question 16

Motor neuron

Answer 16

These cells carry impulses to make the right bits of your body. Effector organs respond

Question 17

Effector

Answer 17

Muscles or glands which respond to the arrival of impulses by contracting

Question 18

Response

Answer 18

Muscles respond by contracting and glands respond by secreting chemical substances

Question 19

Cerebral cortex

Answer 19

Concerned with consciousness, intelligence, memory and language

Question 20

Carebellum

Answer 20

Concerned with mainly coordinating muscular activity and balance

Question 21

Medulla

Answer 21

Concerned with unconscious activities e.g. controlling the heartbeat, movement of the gul and breathing

Question 22

Hypothalamus

Answer 22

Involved in controlling the body temperature

Question 23

Pituitary gland

Answer 23

Produces many different chemicals/hormones which play a big part in coordinating and controlling body systems

Question 24

What are reflexes for

Answer 24

Automatic
Rapid
Protect the body from harm or
Control basic bodily functions e.g. breathing, moving food through gut

Question 25

What do reflex actions involve

Answer 25

Sensory neurons, synapses, relay neurons and motor neurons

Question 26

At the synapse

Answer 26

When impulse from sensory neurone gets to synaptic knob, vesicles containing neurotransmitter mover to nerve cell membrane Release chemicals to synaptic gap and diffuse to next neurone and attach to receptor sights on neurone This starts electrical impulses travelling down neurone

Question 27

At the synapse (arrow diagram)

Answer 27

Electrical impulse —> chemical messages —>electrical impulse

Question 28

What is the eye

Answer 28

Sense organ containing many light and colour sensitive receptors

Question 29

Formation of the retina

Answer 29

All light-sensitive cells are arranged at the back of the eye in special layer known as retina

Question 30

Cornea

Answer 30

Changes direction of light rays coming into eye

Question 31

Iris

Answer 31

Muscle that controls size of pupil- how much light enters the eye

Question 32

Lens

Answer 32

Clear disk that fine-tunes focussing of light rays

Question 33

Retina

Answer 33

Receives light that's lens has focussed and converts to impulses to the brain

Question 34

Optics nerve

Answer 34

Transfers visual informations from retina to visual centres of brain via electrical impulses

Question 35

Binocular vision

Answer 35

Vision using two eyes, range of vision overlaps, can judge distance and see 3D, smaller field of view

Question 36

Monocular vision

Answer 36

Vision using 1 eye, range of vision doesn't overlap, wider field of view as eyes on side of head, unable to judges distance (no 3D)

Question 37

Accommodation for a distant object

Answer 37

Relaxed muscle Taut ligaments Longer and flatter lens

Question 38

Accommodation for a near object

Answer 38

Contracted muscles Slack ligaments Shorter and fatter lens

Question 39

Muscles and ligaments in eye and function

Answer 39

Ciliary muscles and suspensions ligaments act together to push or pull on lens. Fatter the lens, the more the light is refracted

Question 40

What is short sightedness

Answer 40

Myopia | Unable to focus on distant things

Question 41

What is long sightedness

Answer 41

Hyperopia | Unable to focus on nearer objects

Question 42

How can myopia be corrected

Answer 42

Concave lens refracts light outwards before it hits the cornea then image focuses on retina

Question 43

How can hyperopia be corrected

Answer 43

Convex lens refracts light inwards before it hits the cornea then focuses on the retina

Question 44

Advantage and disadvantage of contact lenses

Answer 44

Better for sport, more comfortable | Can cause eye infections, have to be sterilised at night

Question 45

Advantage and disadvantage of laser eye surgery

Answer 45

Used to treat both myopia and hyperopia many don't need to wear glasses/ lenses Only available to adults once eye stops growing

Question 46

Advantage and disadvantage of replacement lenses

Answer 46

Corrects visual impairment permanently | Damage to retina, cataracts and infection

Question 47

What is laser eye surgery

Answer 47

Changes shape of cornea not lens

Question 48

What are replacement lenses

Answer 48

Add contact lenses over, removes lens and replaces with new one