vision

Question 1

fibrous tunic

Answer 1

outer layer
protection

Question 2

vascular tunic

Answer 2

middle layer
nutrition

Question 3

retina

Answer 3

inner layer
transduction

Question 4

sclera

Answer 4

white
protective
outer layer of eyeball

Question 5

cornea

Answer 5

transparent outer surface of the eye
bends and refracts light

Question 6

choroid

Answer 6

highly vascular
very thin
lines nearly the entire inner surface of sclera
brown
designed to prevent light rays from bouncing back out the eye ball

Question 7

iris

Answer 7

coloured part of the eye
being the anterior chamber
controls the amount of light entering the eye

Question 8

retina

Answer 8

dark spot - macula and fovea
light spot - optic nerve

Question 9

astigmatism

Answer 9

cornea improperly shaped
light entering the eyes os not properly bent
inability to properly focus the image onto the retina

Question 10

glaucoma

Answer 10

cilliary bodies clog up
improper drainage of waste
excess of aqueous humour
intraocular pressure

Question 11

presbyopia

Answer 11

old sight
inability of the lens to accomadate properly
loss of elasticity in the lens with age

Question 12

albinism

Answer 12

due to lack of pigment in the iris
a pinkish hue of the eye

Question 13

fractional eye movement

Answer 13

small involuted eye movements that occur during visual fixation
- mircosaccades
- ocular microtremor
- ocular drift

Question 14

saccadic movements

Answer 14

quick, simultaneous movements of both eyes in the same direction

Question 15

smooth pursuit

Answer 15

ability of the eyes to smoothly follow a moving object

Question 16

vergence movements

Answer 16

simultaneous movement of both eyes in opposite directions

Question 17

vestibule ocular reflex

Answer 17

reflex eye movement that stabilises the images on the retina
works in total darkness or when eyes are closed

Question 18

optokinetic reflex

Answer 18

allows the eye to follow objects in motion when the head remains stationary

Question 19

retina

Answer 19

outer segment - components for light absorption
inner segment - protein synthesis and energy production

Question 20

phototransduction

Answer 20

• light strikes the retina
• the retinal is transformed, opsin also transformed
• generation of electrical impulse, transmits through the optic nerve to the brain for processing

Question 21

horizontal cells

Answer 21

laterally interconnecting neurons in the outer layer of the retina

Question 22

photoreceptors

Answer 22

high light levels - only cone mediated vision is sensitive to light as rods are bleached at high levels
low level light - only rod mediated vision is sensitive enough to detect light

Question 23

rods

Answer 23

night vision
peripheral vision
poor resolution
motion sensitive
high convergence

Question 24

cones

Answer 24

daylight vision
foveal vision
high resolution
colour sensitive
low convergence

Question 25

midget ganglion

Answer 25

small sized centric trees and cell bodies

Question 26

parasol ganglion

Answer 26

large sized dendritic trees and cell bodies

Question 27

photosensitive ganglion cells

Answer 27

contain their own photopigment respond to light even in absence or rods and cones project to the SCN

Question 28

retinal ganglion cells

Answer 28

exit the eyes at the optic disc and travel via the optic nerve to the optic chiasm

Question 29

optic chiasm

Answer 29

half the fibres cross to hemispheres opposite to left and right visual hemifeilds

Question 30

lateral geniculate nucleus

Answer 30

80% of the optic fibres terminate in thalamus

Question 31

superior coliculus

Answer 31

20% of optic fibres terminate in midbrain

Question 32

ventral pathway

Answer 32

what temporal lobe object recognition

Question 33

dorsal pathway

Answer 33

where parietal lobe

Question 34

appreciative agnosia

Answer 34

damage to occipital lobe inability to perceive entire perceptions unable to draw/copy or recognise objects perceive local properties but not wholes

Question 35

appreciative agnosia 2

Answer 35

image to parietal lobe inability to recognise objects if contour degraded or in a atypical position

Question 36

hemispatial neglect

Answer 36

damage generally in right parietal lobe pr right temproroparertial junction