communications

Question 1

define accomodation

Answer 1

eye changes shape of the lens to achieve a focused image of either distant or nearby objects

Question 2

define aqueous humor

Answer 2

is the liquid between the lens and the cornea that is responsible for refracting light

Question 3

define auditory nerve

Answer 3

transmits electrical messages from ear to brain so that sound can be interpreted

Question 4

define cataract

Answer 4

clouding of the lens

Question 5

what does the cerebellum do ?

Answer 5

regulates coordination

Question 6

define choroid

Answer 6

a layer between the sclera and the retina, provides oxygen and nourishment

Question 7

define colour blindness

Answer 7

inability to detect particular colours caused by a lack of specific colour cone cells

Question 8

define cone cells

Answer 8

light sensitive cell found on the retina of the eye, particularly important in colour perception- concentrated @ the fovea

Question 9

define cornea

Answer 9

transparent layer at the front of the eye, refracts incoming light

Question 10

define effector

Answer 10

a muscle or gland that produces a response to a stimulus

Question 11

define fovea

Answer 11

point on the retina with the greatest account and the greatest number of cone cells (6.5 million)

Question 12

define incus

Answer 12

one of the three small bones in the middle ear

Question 13

define ion

Answer 13

a charged atom or group of atoms

Question 14

define iris

Answer 14

coloured part of the eye, controls the amount of light entering the eye

Question 15

define labyrinth

Answer 15

organ in the inner ear that is responsible for balance

Question 16

define lateral line

Answer 16

a visible line along the head and body of fish and amphibians, senses low frequency sound

Question 17

define malleus

Answer 17

first of three small bones in the middle ear

Question 18

define acuity

Answer 18

sharpness of vision

Question 19

define axon

Answer 19

an extension on a neurone that takes the impulse away from the cell body

Question 20

define binocular

Answer 20

involving the use of two eyes with overlapping field of view resulting in depth perception

Question 21

define bioluminescence

Answer 21

the production of light by living organismss

Question 22

define blind spot

Answer 22

the place on the retina where the opt nerve leaves the eye, contains no light sensitive cells

Question 23

define ceteceans

Answer 23

order of marine mmala

Question 24

define ciliary body

Answer 24

contains the suspensory ligaments and the ciliary muscles in the eye

Question 25

define ciliarymuscles

Answer 25

small musclesattatched to the lens that change the shape of the lens to focus on near and far objects

Question 26

define mechanoreceptors

Answer 26

a receptor that responds to sound, pressure, such and position

Question 27

define medulla oblongata

Answer 27

involuntaryactions

Question 28

define monocular

Answer 28

vision from one eye

Question 29

define myelin sheath

Answer 29

a mixture of fat and proteins that acts as an insular around neurones

Question 30

define myopia

Answer 30

short sightedness

Question 31

define nerve

Answer 31

a bundle of neuronal fibres

Question 32

define neuromasts

Answer 32

sensory cells found in the lateral line organ of fish and amphibians

Question 33

define neurone:

Answer 33

a single nerve cell

Question 34

define neurotransmitters

Answer 34

chemicals that transmit the nerve impulse in the synapse between two neurones

Question 35

define ocelli

Answer 35

simple eye spot

Question 36

define ommatlia

Answer 36

visual units of the compound eye of invertebrates

Question 37

define optic nerve

Answer 37

nerve that leaves the retina of the eye

Question 38

define otolith

Answer 38

calcareous mass found in the ear of some vertebrates, important in sound perception in fish

Question 39

define oval window

Answer 39

the connecting plate between the middle ear and inner ear

Question 40

define peripheral

Answer 40

on the outer side

Question 41

define pheromone

Answer 41

chemicals released as a signal

Question 42

define photoreceptor

Answer 42

an organ or cell, sensitive to light

Question 43

define pitch

Answer 43

function of the frequency of a wave, high or low sounds have high or low pitch

Question 44

define polarisation

Answer 44

separation of positive and negative ions

Question 45

define pupil

Answer 45

the opening in the iris of the eye

Question 46

define receptor

Answer 46

detect changes in the environment

Question 47

define recessive

Answer 47

not expressed in the phenotype unless it is the only gene present

Question 48

define refraction

Answer 48

bending of light

Question 49

define refractory period

Answer 49

the time taken for a neurone to recover afterfiring

Question 50

define resting potential

Answer 50

the normal state of a neurone, negatively charged internally

Question 51

define retina

Answer 51

light sensitive lining on the back of the eye

Question 52

define rhodopsin

Answer 52

light sensitive pigment found in rod cells

Question 53

define rod cells

Answer 53

light sensitive cells especially useful for the detection of low light

Question 54

define schwann cells

Answer 54

a type of cell that produces the myelin sheath around nerve cells

Question 55

define sclera

Answer 55

tough white coating in the eye

Question 56

define sex linkage

Answer 56

a gene found on one of the sex chromosomes

Question 57

define sound shadow

Answer 57

the acoustic shadow cast by the head, used in the localisation of sound

Question 58

define spike

Answer 58

a graphical interpretation of the firing of a neurone

Question 59

define stapes

Answer 59

the third bone in the middle ear

Question 60

define stereocilia

Answer 60

hair like extensions on hair cells that contact the tectorial membrane and send an impulse to the brain

Question 61

define stimuli

Answer 61

an external message that excites a receptor

Question 62

define stimulus

Answer 62

singular of above

Question 63

define synapse

Answer 63

the gap between two neurones

Question 64

define syrinx

Answer 64

the voice box of birds

Question 65

define threshold

Answer 65

a level of intensity necessary to fire a neurone

Question 66

define transparent

Answer 66

clear, see through

Question 67

define tympanic organ

Answer 67

a hearing organ found in insects that is similar in structure to the mammalian eardrum

Question 68

define vitreous humour

Answer 68

jelly like substance that fills the eye between the lens and the retina