physiology

Question 1

what is the sense organ of tase

Answer 1

tastebuds

Question 2

life span of tastebuds

Answer 2

10 days

Question 3

where are tastebuds found

Answer 3

tongue, palate, epiglottis and pharynx

Question 4

where are the majority of tastebuds found

Answer 4

in the papillae of the tongue

Question 5

name the 4 types of papillae of the tongue

Answer 5

filliform, fungiform, vallate and foliate

Question 6

which type of papilla of the tongue doesn’t contain taste buds

Answer 6

filliform

Question 7

pathway of tasting

Answer 7

binding of chemical to receptor cells produces depolarising potential
initiates action potential in afferent nerve fibres
signals conveyed by cranial nerves via brainstem and thalamus to cortical gustatory area

Question 8

name the 5 primary tastes

Answer 8

bitter, sour, salty, sweet and umami

Question 9

what is aguesia

Answer 9

loss of taste function

Question 10

what is dysguesia

Answer 10

distortion of taste function

Question 11

what is hypoguesia

Answer 11

reduced taste function

Question 12

where is olfactory neuroepithelium found

Answer 12

the olfactory cleft

Question 13

what is olfactory neuroepithelium composed of

Answer 13

pseudostratified columnar epithelium

Question 14

name the 4 main cells in olfactory epithelium

Answer 14

basal cells
supporting cells
bi-polar sensory (afferent) neurone
duct cell of bowmans gland

Question 15

role of basal cells in olfactory neuroepithelium

Answer 15

form the new stem cells from which the new olfactory cells can develop

Question 16

role of duct cell of bowmans gland in olfactory neuroepithelium

Answer 16

secretes mucous

Question 17

process of smelling

Answer 17

smell detected by olfactory receptors
axons assemble into bundles of nerves
enter the cranial cavity via the cribiform plate
enter the olfactory bulb which transmits info along the olfactory tract to each temporal lobe and olfactory areas

Question 18

where is the olfactory bulb located

Answer 18

lies in the olfactory groove within the anterior cranial fossa

Question 19

approximately how much inspired air reaches the olfactory neuroepithelium

Answer 19

10-15%

Question 20

how do odorants reach smell receptors during quiet breathing

Answer 20

diffusion

Question 21

what is the role of mucous (2)

Answer 21

moist and protective environment
aids in dispersing odorants to the olfactory receptors

Question 22

what is anosmia

Answer 22

inability to smell

Question 23

what is hyposmia

Answer 23

reduced ability to smell

Question 24

what is dysosmia

Answer 24

altered sense of smell

Question 25

what is phantosmia

Answer 25

spell perceived in the absence of a stimulus

Question 26

name 3 conductive causes of abnormality in smell

Answer 26

nasal polyps rhinitis nasal mass

Question 27

what is used to assess olfaction

Answer 27

UPSIT (scratch and sniff)

Question 28

name some sensorineural causes of abnormality of smell

Answer 28

viral head trauma neurological conditions: parkinsons, dementia brain tumours medications

Question 29

what is sound

Answer 29

a pressure caused by oscillating molecules set in motion by a vibration

Question 30

what frequency of sound can humans perceive

Answer 30

20-20,000 Hz

Question 31

role of the middle ear in hearing

Answer 31

amplifies sound

Question 32

role of the inner ear in hearing

Answer 32

receives mechanical signals and converts them into electrical signals

Question 33

movement of mechanical signals in ear (hearing)

Answer 33

footplate of stapes vibrates oval window creates pressure waves in the perilymph of cochlea transmitted to the endolymph in the cochlear duct basilar membrane vibrates causing hair cells on the organ of corti to move against the tectorial membrane stimulating depolarisation stimulation of CN8

Question 34

from when can a foetus hear in utero

Answer 34

18 weeks

Question 35

from when can a foetus respond to sound/voice in utero

Answer 35

26 weeks

Question 36

what stimulates hair cells in the membranous labyrinth of the inner ear

Answer 36

the movement of endolymph

Question 37

what senses head position

Answer 37

utricle and saccule

Question 38

what is the sense organs of the utricle and saccule

Answer 38

macula

Question 39

position of macula in utricle and saccule and how it relates to function

Answer 39

90 degrees to each other so they can respond to positions in different planes

Question 40

how do the utricles and saccules work

Answer 40

contain otoliths which move due to gravity when the head moves this causes sterocilia to bend initiating action potentials in the vestibular nerve fibres

Question 41

what senses head movement

Answer 41

semi-circular canals

Question 42

what are the semi-circular canals

Answer 42

3 ring-like extensions from the vestibule

Question 43

orientation of the semi-circular canals

Answer 43

one in the horizontal plane and 2 in the vertical plane

Question 44

what is it called where the base of a semi-circular canal meets the vestibule

Answer 44

ampulla

Question 45

what is contained within the ampulla

Answer 45

crista ampullaris

Question 46

what is the crista ampullaris

Answer 46

hair cell-containing structure which responds to rotational movement

Question 47

role of the vestibulo-ocular reflex

Answer 47

helps maintain visual stability during head movements

Question 48

what is the mechanism of vestibulo-ocular reflex

Answer 48

compensatory eye movements (nystagmus)