A & P - Special Senses

Question 1

what are the purpose of the special senses?

Answer 1

to bring information about external environment to CNS

Question 2

what is the main function of the eye?

Answer 2

to detect visible light in the form of colour

Question 3

what is the conjunctiva of the eye?

Answer 3

lines inner surface of eyelid and covers outer surface of the eye

Question 4

what keeps the conjunctiva moist and clean?

Answer 4

lacrimal glands continually produce tears

Question 5

name the two filled cavities of the eyeball, what are they separated by?

Answer 5

anterior
posterior
separated by lens

Question 6

name the three layers of the eyeball wall, inner to outer

Answer 6

neural
vascular
fibrous

Question 7

in what layer of the eye are the sclera and cornea?

Answer 7

fibrous tunic

Question 8

what are the sclera and the cornea and where in the eye are they located?

Answer 8

sclera - white of eye, around the side of eye

cornea - transparent layer that covers iris and pupil

Question 9

what is the function of the sclera and cornea?

Answer 9

protection of eye and attachment for muscles

Question 10

what does the vascular tunic of the eye consist of?

Answer 10

iris
cilliary body
choriod

Question 11

what is the function of the iris?

Answer 11

pigmented area containing smooth muscle fibres that contracted to change diameter of pupil

Question 12

what is the function of the cilliary body?

Answer 12

thickened area containing suspensory ligaments that hold lens

Question 13

what is the function of the choroid?

Answer 13

contains capillary network

Question 14

what is contained in the neural tunic or retina?

Answer 14

photoreceptors - rods & cones

Question 15

what is the function of the rods and cones?

Answer 15

rods - work in dim light, many

cones - require more light, provide colour vision, fewer

Question 16

what is used to view the retina?

Answer 16

opthalmoscope

Question 17

what is the fovea centralis?

Answer 17

only cones
focused light
used for looking directly at an object

Question 18

what is the optic disc?

Answer 18

where optic nerve leaves the eye and blood vessels enter/leave.
no photoreceptors
blind spot

Question 19

what is diabetic retinopathy?

Answer 19

over accumulation of glucose leads to damage of retinal vessels. leads to oedema and swelling of the macula - blurred vision

Question 20

what is the posterior cavity filled with and why?

Answer 20

vitreous humour (jelly-like)
maintains pressure within eye
keeps space for eyeball

Question 21

what does the anterior cavity consist of?

Answer 21

anterior and posterior chambers - separated by iris

Question 22

what does the anterior cavity contain?

Answer 22

aqueous humour - replaced every 90 mins

Question 23

what is glaucoma?

Answer 23

form of blindness - due to increased intraocular pressure caused by build up of aqueous humour - in turn putting pressure on retina and optic nerve

Question 24

where in the eye is light focused?

Answer 24

retina
cornea
lens
humours

Question 25

how are action potentials transmitted from the eye to the brain?

Answer 25

light strikes retina | action potential transmitted along optic nerve to occipital cortex in brain

Question 26

where do the two optic nerves connect?

Answer 26

optic chiasma

Question 27

where do axons from the optic chiasm pass to?

Answer 27

visual cortex in occipital lobe

Question 28

what is another function of the ear besides hearing?

Answer 28

balance

Question 29

name the three parts of the ear

Answer 29

external middle inner

Question 30

name the three areas of the external ear

Answer 30

auricle tympanic membrane external acoustic (auditory) meatus

Question 31

what is the function of the auricle?

Answer 31

supported by cartilage | collects sound waves

Question 32

what is the function of the tympanic membrane?

Answer 32

separates external and middle ear | sound waves cause eardrum to vibrate

Question 33

what is the function of the external acoustic (auditory) meatus?

Answer 33

passageway extending through temporal bone to eardrum glands produce cerumen (wax) hairs in canal and wax trap foreign objects, protecting tympanic membrane

Question 34

what separates the middle and inner ear?

Answer 34

oval and round windows

Question 35

name the 3 auditory ossicles in the middle ear

Answer 35

malleus incus stapes

Question 36

what is the function of the auditory ossicles?

Answer 36

to transmit vibrations from tympanic membrane to oval window

Question 37

how many times larger is the tympanic membrane than the oval window, what effect does this have?

Answer 37

20 times | force of vibration is increased by x20

Question 38

what connects the middle ear to the nasopharynx?

Answer 38

Eustachian tube (auditory tube)

Question 39

what is otitis media?

Answer 39

middle ear infection | infection spreads from nasopharynx up the auditory tube, if sever pus build up can rupture tympanic membrane

Question 40

what does the inner ear consist of?

Answer 40

series of interconnecting bony, fluid filled channels in temporal bone

Question 41

what is the cochlear concerned with?

Answer 41

hearing

Question 42

what are the vestibular and semi-circular canals concerned with?

Answer 42

balance

Question 43

what transmits impulses from the inner ear to the brain?

Answer 43

vestibulocochlear nerve (CN VIII)

Question 44

how is sound transmited through the ear?

Answer 44

sound waves collect in auricle sound waves hit tympanic membrane vibration transmitted and amplified through ossicles vibration of stapes on oval window causes fluid in cochlea to vibrate vibrations stimulate spiral organ triggering AP

Question 45

where does the information from the cochlea go?

Answer 45

primary auditory cortex in temporal lobe

Question 46

name two types of hearing impairment

Answer 46

conductive | sensorineural

Question 47

what is a conductive hearing impairment?

Answer 47

deficiency in transmitting sound waves form outer to inner ear

Question 48

what is a sensorineural hearing impairment?

Answer 48

involves spinal organ, neural pathway or primary auditory pathway

Question 49

which parts of the ear are concerned with balance?

Answer 49

vestibule - static equilibrium | semi-circular canals - kinetic equilibrium

Question 50

what does the vestibule consist of?

Answer 50

utricle | saccule

Question 51

how are action potential transmitted from the vestibule and the semi-circular canals?

Answer 51

via vestibulocochlar nerve to brainstem

Question 52

what causes motion sickness?

Answer 52

continual stimulation of semi circular canals

Question 53

what is the sense of smell?

Answer 53

response to airbourne molecules (odorants)

Question 54

what does the olfactory system consist of?

Answer 54

olfactory epithelium olfactory nerve (CNI) olfactory bulb and tract

Question 55

describe the process of smelling

Answer 55

1. odorant enter nasal cavity 2. presented to receptor protein on olfactory epithelium 3. olfactory nerve stimulated 4. info transmitted to olfactory cortex

Question 56

what is anosmia?

Answer 56

inability to smell - can be congenital or acquired

Question 57

where are taste buds located?

Answer 57

tongue soft palette pharynx epiglottis

Question 58

how many taste cells does each bud contain?

Answer 58

40

Question 59

describe a taste cell

Answer 59

each has ting hair-like projections. | sensory receptors of taste hair

Question 60

list the 5 tastes

Answer 60

``` sweet sour salty bitter umani ```

Question 61

name the areas of the tongue which are most sensitive to certain tastes.

Answer 61

front - sweet sides - sour back - bitter

Question 62

describe the process of tasting

Answer 62

1. tastants bind to receptors on taste hairs 2. action potential initiated in sensory neuron 3. sensory axons (facial, glossopharyngeal, vagus nerves)transmit AP 4. info transmitted to taste cortex in partial lobe

Question 63

name three types of taste loss

Answer 63

ageusia - total loss hypogeusia - partial loss dysgeusia - distortion or alteration of taste

Question 64

what can cause taste loss?

Answer 64

neurological damage side effects of drugs endocrine disorder radiation therapy