Physiology

Question 1

Receptors for taste and smell are what kind? How are these stimulated?

Answer 1

Chemoreceptors- stimulated by binding to particular chemicals

Question 2

What do taste and smell sensations influence in association with food intake?

Answer 2

The flow of digestive juices

Question 3

Taste perception is influenced by what?

Answer 3

Information from smell receptors

Question 4

The sensory receptor cells for taste are mainly packed in where?

Answer 4

Taste buds

Question 5

What two cell types do taste buds consist of? How are these arranged?

Answer 5

Sensory receptor cells and support cells arranged consecutively

Question 6

Taste receptor cells have a lifespan of how long? They are replaced from what?

Answer 6

10 days- replaced from basal cells within the taste buds

Question 7

Where are taste buds mainly found?

Answer 7

Tongue, epiglottis, palate, pharynx

Question 8

Taste receptor cells synapse with what?

Answer 8

Afferent nerve fibres

Question 9

The majority of tastebuds sit on what structure of the tongue?

Answer 9

Papillae

Question 10

What are the 4 types of tongue papillae? Which one does not contain taste buds?

Answer 10

Fungiform, vallate, foliate, filiform (does not contain)

Question 11

When taste provoking chemicals bind to receptor cells, what happens to the membrane potential?

Answer 11

It depolarises

Question 12

Afferent taste fibres reach the brainstem in the taste response via what 3 nerves and from where?

Answer 12

CNVII (chord tympani) from anterior 2/3rds of tongue, CNIX from posterior 1/3rd of tongue, CNX from epiglottis and pharynx

Question 13

What chemicals trigger each of the different types of taste:

a) salty? b) sour? c) sweet? d) bitter? e) umani?

Answer 13

a) NaCl b) free H+ ions c) glucose d) alkaloids and poisonous substances e) amino acids (glutamate)

Question 14

What do each of the following mean:

a) aguisia? b) hypoguisia? c) dysguisia?

Answer 14

a) loss of taste function b) reduced taste function c) distortion of taste function

Question 15

What are some causes of aguisia?

Answer 15

Nerve damage, local inflammation, some endocrine conditions

Question 16

What are some causes of hypoguisia?

Answer 16

Chemotherapy and medications

Question 17

What 3 cell types are found in the olfactory mucosa?

Answer 17

Receptor cells, supporting cells, basal cells

Question 18

Which cells in the olfactory mucosa secrete mucus?

Answer 18

Basal cells

Question 19

What do odourants bind to?

Answer 19

Cilia which projects out from the olfactory mucosa

Question 20

How long is the lifespan for olfactory receptors?

Answer 20

2 months

Question 21

What do axons of olfactory receptors collectively form?

Answer 21

Afferent fibres of the olfactory nerve

Question 22

Where do afferent fibres of the olfactory nerve pierce to reach the brain?

Answer 22

Cribiform plate of the ethmoid bone

Question 23

How do odourants reach smell receptors during quiet breathing?

Answer 23

Diffusion

Question 24

A substance must have what two properties in order to be smelled?

Answer 24

Sufficiently volatile and water soluble

Question 25

What may be some causes of anosmia and hyposmia?

Answer 25

Viral infections, allergy, nasal polyps, head injury

Question 26

What may hyposmia be an early sign of?

Answer 26

Parkinson's disease

Question 27

Give two examples of dysmosia?

Answer 27

Differently interpreting smells, hallucinations of smells

Question 28

Lots of waves on a sound graph suggests what?

Answer 28

High frequency- high pitch

Question 29

Few waves on a sound graph suggest what?

Answer 29

Low frequency- low pitch

Question 30

High peaked waves on a sound graph suggest what?

Answer 30

High amplitude- loud

Question 31

Low peaked waves on a sound graph suggest what?

Answer 31

Low amplitude- quiet

Question 32

Which parts of the ear are: a) only associated with hearing? b) associated with hearing and balance?

Answer 32

a) Outer and middle, b) Inner

Question 33

What is the function of the middle ear?

Answer 33

Amplify sound and pass vibrations via the oval window to the inner ear

Question 34

What is the function of the Eustachian tube?

Answer 34

Ventilates the middle ear

Question 35

What is the resting state of the Eustachian tube?

Answer 35

Closed

Question 36

What muscles are responsible for opening the Eustachian tube?

Answer 36

Tensor veli palatini and levator palatini

Question 37

When sound vibrations are passed through the oval window into the middle ear, what does this start?

Answer 37

Movement of the perilymph fluid

Question 38

What is suspended within the perilymph?

Answer 38

Endolymph

Question 39

What is the membranous labyrinth?

Answer 39

A series of sacs and ducts within the bony labyrinth

Question 40

When sound waves are deflected towards the longest stereo cilia hairs in the middle ear, what does this cause?

Answer 40

Depolarisation

Question 41

When sound waves are deflected away from the longest stereo cilia hairs in the middle ear, what does this cause?

Answer 41

Hyperpolarisation

Question 42

Sound waves pass through the cochlea, maximally stimulating an area of where?

Answer 42

Basilar membrane

Question 43

What is the function of the organ of corti within the basilar membrane of the cochlea?

Answer 43

Stimulates the cochlear nerve and central pathways - culminates activity in the superior temporal gyrus

Question 44

What is sensory conflict, in terms of balance?

Answer 44

When visual input does not match proprioceptive input

Question 45

What are the otolith organs?

Answer 45

Maculae of the utricle and saccule

Question 46

In the vestibular area, what is fluid controlled by?

Answer 46

The movement of the head

Question 47

What do semicircular canals detect and how?

Answer 47

Different directions of head movement based on the movement of the fluid inside them

Question 48

Which parts of the inner ear are responsible for sending signals to the brain about the direction of head movements?

Answer 48

Hair cells of the utricle and saccule