Nervous system TOPIC 5

Question 1

name a

Answer 1

suspensory ligaments

Question 2

name b

Answer 2

iris

Question 3

name c

Answer 3

pupil

Question 4

name d

Answer 4

cornea

Question 5

name e

Answer 5

lens

Question 6

name f

Answer 6

optic nerve

Question 7

name g

Answer 7

blind spot

Question 8

name h

Answer 8

scelera

Question 9

name i

Answer 9

retina

Question 10

name j

Answer 10

ciliary muscles

Question 11

what is the function of the scelera

Answer 11

white outer layer of the eye; it is relatively tough and strong so the eyeball is not easy to damage

Question 12

what is the function of the cornea

Answer 12

transparent area at the front of they eyeball; lets light into the ey, cureved surface to change the direction of the rays

Question 13

what is the function of the iris

Answer 13

controls the size of the pupil; made of muscles that contract or relax to chnage the size of the pupil, controlling the amount of light reaching hte retina

Question 14

what is the function of the pupil

Answer 14

the hole which light enters the eye through

Question 15

what is the function of the lens

Answer 15

a clear disc which ‘fine tunes’ the focusing of the light rays

Question 16

what is the function of the suspensory ligaments and ciliary muscles

Answer 16

change the shape of the lens to fine focus light onto the retina

Question 17

what is the function of the retina

Answer 17

holds the light sensitive cells

Question 18

what is the function of the optic nerve

Answer 18

carries impulses from retina to brain

Question 19

what is the function of the blind spot

Answer 19

the point where the optic nerve leaves the eye

Question 20

what happens to the pupil in dim light

Answer 20

the pupil is enlarged so as much light as possible enters the eye

Question 21

what happens to the pupil in bright light

Answer 21

the iris makes the pupil very small, reducing the light entering the eye

Question 22

why does the pupil change shape in brighter lights

Answer 22

so that too much light doesn’t damage the delicate, light-sensitive cells

Question 23

name the process which focusses light

Answer 23

refraction

Question 24

how is the shape of the lens changed

Answer 24

by the contraction or relaxation of the ciliary muscles

Question 25

why is it important for light to be focused on the retina

Answer 25

if the light is focused before and past the retina then the image formed is blurry

Question 26

what is the function of the eyelid

Answer 26

protect the eye from physical harm

Question 27

where are the radial muscles in the eye

Answer 27

they run outwards from the pupil like the spokes of a wheel

Question 28

where are the circular muscles in the eye

Answer 28

arranged around the pupil

Question 29

what ar ethe two set of muscles which the iris contains

Answer 29

- radial muscles - circular muscles

Question 30

describe the light rays entering your eye from a distant object

Answer 30

almost parallel

Question 31

describe the light rays entering your eye from a near object

Answer 31

diverging very strongly

Question 32

what is accomodation

Answer 32

the process of chnaging the shape of the lens to focus on near or distant objects

Question 33

explain the eyes movements when focusing on a distant object

Answer 33

- cilary muscles relax - suspensory ligaments are pulled tight - the lens is pulled flat and tight - light rays are only refracting slightly

Question 34

explain the eyes movemetns when focusing on a near object

Answer 34

- cilary muscles contract - suspensory ligaments loosen - the lens is more curved and thicker - refracts light rays strongly

Question 35

what is homeostasis

Answer 35

the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to interal and external changes

Question 36

what are examples of effectors

Answer 36

- muscles - glands

Question 37

what do receptors do

Answer 37

detect stimuli

Question 38

what are the coordination centres and what do they do

Answer 38

- brain - spinal cord - pancreas recieve and process information from receptors

Question 39

what are the names given to nerve cells

Answer 39

neurons

Question 40

what is the junction between neurons called

Answer 40

a synapse

Question 41

where are the two synapses

Answer 41

- between the sensory neurone and the relay neurone - between the relay neurone and the motor neurone

Question 42

explain a synapse

Answer 42

- neurotransmitter is releasedd from the end of the anox of the sensory neurone into the synaptic cleft - the neurotransmitter diffuses across the gap - passes the electrical nerve impulse to the next neurone

Question 43

what are the two responses of an effector

Answer 43

- if muscle : contract - if gland : secrete a hormone

Question 44

what are the portective membranes encasing the brain called

Answer 44

meninges

Question 45

what are the three sections of the brain

Answer 45

- cerebral cortex - cerebellum - medula

Question 46

name the part of the brain which controls body temperature

Answer 46

the hypothalamus

Question 47

what does the cerebral cortext do

Answer 47

- consciousness - intelligence - memory & language

Question 48

what does the cerebellum do

Answer 48

- coordinates muscular activity - balance

Question 49

what does the medulla do

Answer 49

- unconscious activities - control heartbeat - breathing

Question 50

what is the order of the reflex arc

Answer 50

- nerve impulse - sensory neurone - relay neurone - motor neurone - muscle

Question 51

what are the two types of eye defects

Answer 51

- myopia - hyperopia

Question 52

describe myopia

Answer 52

- can see close objects in clear focus - distant objects look blurred - light is focused infront of the retina - lens is too curved

Question 53

explain how to treat myopia

Answer 53

- wear glasses with a concave lens - spread out the light from distant objects - thicker lens

Question 54

describe hyperopia

Answer 54

- can see distant objects clearly - close objects are blurred - light is focused behind the retina - lens is too flat annd thin

Question 55

explain how to treat hyperopia

Answer 55

- wear glasses with a convex lens - converge the light rays before reaching eye itself - thinner lens

Question 56

what are the benefits of studying the brain

Answer 56

understanding how our brain works helps to develop new drugs and medical treatments for some disorders and diseases

Question 57

what are the risks of studying the brain

Answer 57

any surgery on the brain carriers risks of damage (due to delicate structure of the brain and the invasive procedures that are used)

Question 58

what is the internal body temperature

Answer 58

37°C

Question 59

what inside the hypothalamus controls the bodys core temperature

Answer 59

the thermoregulatory centre

Question 60

how does the thermoregulatory centre work

Answer 60

contains receptors that are sensitive to temperature changes in the blood flowing through the brain

Question 61

what happens in the process of cooling down the body

Answer 61

- surface skin capillaries dilate (vasodilation), more blood flows through capillaries, transfer more energy by radiation from skin to the surrounds - produce more sweat, water evapourates transferring energy to environment - hairs lie flat to skin

Question 62

what happens in the process of keeping the body warm

Answer 62

- surface skin capillaries contrict (vasoconstriction), reduces energy transferred by radiation - sweat production is stopped - skeletal muscles contract and relax rapidly, causing shivering, an exothermic reaction - hairs pulled erect to trap insullating layer of air