BMS11004 - WEEK 7 THURSDAY

Question 1

give functions of chemical senses

Answer 1

identify food sources, avoid noxious substances, find mate or mark territories

Question 2

whats umami tastes

Answer 2

amino acids, “savoury”, importance for protein synthesis, NT

Question 3

what is salty tastes importance for

Answer 3

physiological process

Question 4

whats sour taste important for

Answer 4

avoiding rotting foot and injury of GI

Question 5

what are lingual papillae

Answer 5

contains taste buds “taste cells group”
4 types: filiform, foliate, fungiform, circumvallate

Question 6

what are filiform lingual papillae

Answer 6

spiked, no taste bud, sense texture, most abundant

Question 7

what are foliate lingual papillae

Answer 7

ridges with invaginations

Question 8

what are fungiform lingual papillae

Answer 8

mushrooms, mainly at sides and front

Question 9

what are circumvallate lingual papillae

Answer 9

pimples, large, contain about half of all taste buds (have invaginations)

Question 10

give taste organs

Answer 10

tongue, cheeks, soft palate, pharynx, epiglottis

Question 11

how many taste buds is there

Answer 11

2000-5000

Question 12

how many chemoreceptive taste cells per taste bud

Answer 12

100

Question 13

describe structure of chemoreceptor taste cell

Answer 13

taste pore with microvilli sticking out for sensory transduction
apical portion= microvilli to increase SA
vasal portion= more synaptic area of cell

Question 14

whats taste transduction dependent on

Answer 14

which membrane receptors are expressed, ENaC

Question 15

in salty and sour tastes, what is used

Answer 15

ion channel
epithelial sodium channel allow Na to etner for salty, H+ for sour

Question 16

in umami, bitter and sweet tastes, what is used

Answer 16

GPCRs, made up of different subunits depending on the taste

Question 16

explain olfactory receptor cells (what type of neuron, where is transduction machinery found, type of axon)

Answer 16

bipolar chemoreceptive neurons, odorant must dissolve in mucus to reach them, transduction machinery is in cilia at end of dendrite, thin unmyelinated axon, are regularly replaced

Question 16

how large is olfactory epithelium

Answer 16

10cm”2
where olfactory receptor cell sits

Question 16

what are gustatory afferents

Answer 16

separate to taste cells and require NT release across clefts

Question 17

how many odorant receptor proteins does human have

Answer 17

350

Question 18

how many odorant receptors are detected by cells

Answer 18

olfactory receptor cell express 1 odorant receptor, which can recognise multiple odorants

Question 19

what are Golfs

Answer 19

used by odorant receptor proteins
using downstream pathway and use adenylyl cyclase
cAMP bind to ligand gated channel, opens, Na, Ca enter
depolarise
cl- bind to another set, open, then leave cell cause depolarise
amplifies GP

Question 20

how do sensory transduction occur

Answer 20

via Golfs

Question 21

outline olfactory projections

Answer 21

each glomerulus of olfactory bulb receive input from 1 type of olfactory receptor if high enough in conc then AP cause convergence of multiple different olfactory receptors signal on 2nd order neurons

Question 22

define convergence

Answer 22

axons from multiple neurons come together, converging in one area onto certain set of second order neurons

Question 23

explain how primary sensory neurons are first order neurons

Answer 23

synapse onto 2nd order neurons (that carries info from glomeruli to various regions of brain)