Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neuro > OLFACTION > Flashcards

OLFACTION Flashcards

(79 cards)

Start Studying
0
Q

trigeminal nerve endings in

A

mucous membrane in mouth

much less sensitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

part of NS dedicated to detection of chemicals

A

trigeminal
olfactory
gustatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

trigeminal purpose

A

sensing noxious chemicals such as vinegar, ammonia, etch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

capsacin activates

A

a TRP ion channel that lets Na and Ca flow through
depolarizes nocicpetor fibers which makes you sense pain and heat
also activated by heat–can be desensitized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

reasons why olfactory system

A

broad discrimitory powers

high sensitivity to odorants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

average human thresholds

A

10^-12 –> 10^14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

at 50-70 years of age..

A

our olfactory capabilities are less than 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

anosmia

A

selective deficits in olfactory sensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

androstadienon

A

male hormone in sweat that promotes mood and arousal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

vomeronasal organ

A

plays an important role in pheromone detection in many animals, but not humans
–many animals there is a small pit in the roof of the mouth that contains epithelial tissue and pheromone receptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

most of the nasal epithelium

A

respiratory epithelium cilitated respiratory cells, and goblet cells that secrete mucous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

olfactory receptor cells are restricted to

A

upper concha and part of middle one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

olfactory epithelium appearance

A

yellowish pigmentation, thought to be due to accumulation of carotinoid pigment (no functional effect)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

three types of cells in olfactory system

A

1) basal cells
2) support cells
3) receptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

basal cells

A

precursors of receptor cell populations that undergoes continual turnover
average lifespan about 60 days (entire population turns over every 6-8 weeks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

support cells

A

apical surface with microvilli, isolate and support receptor cells, and may have nutritional role

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

receptor cells

A

soma with distal dendrite projecting to epithelial surface and an unmyelinated axon that aggregates with others into fasicles–>become ensheathed in schwann cells and form olfactory nerve (cranial nerve I) before passing through cartilaginous and porous cribiform plate and forming synapses in the olfactory bulb of CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

mucous layer is

A

replaced every ten minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

olfactory bulb

A

contains spherical structures called glomeruli, which are endings of receptor cell axons and mitral cell dendrites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

mitral cells

A

principal projection neurons of olfactory bulb, and are the only ones to project to other regions of brain
**have a high degree of convergence at first synapse of system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

oral extremity of the epithelium projects

A

mainly to anterior bulb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

aboral epithelium

A

posterior portion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

continual neurogenesis

A

population of receptor cells turns over every 6-8 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

olfactory sensitivity is in part due to

A

large numbers of olfactory receptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
olfactory neurons respond to odorant stimulation..
with a change in rate at which fire action potentials (thought to arise in change in membrane conductance of receptor cell--> depolarization to threshold)
25
what is signal transduction?
changing a chemical signal to an electrical one
26
where does signal transduction occur?
in the cilia
27
odorant receptors are
GPCR with 7 membrane spanning regions-->activate ion channels in cilia -->some cause changes in adenylate cyclase activity and cAMP
28
phospholipase C mechanism
rapid increase in membrane lipid phosphotidylinositol via phospholipase C-->IP3-->open Ca2+ selective channels
29
an olfactor cell may respond to
one odorant or many | -->thresholds of detection may differ by order of magnitude
30
olfactory epithelium acts as a "gas chromatograph"
sorts out molecules and is absorbed in different epithelium domains
31
receptor neurons expressing same odorant receptor converge in
same glomerulus
32
odorants represented in epithelium by``
patterns correlated with odorant identity adn concentration
33
across fiber pattern
quality of odorant encoded in the pattern of activity in a large number of cells simultaneously -->pattern includes not only which cells are active, but their temporal pattern of activity, as well
34
central processing in olfactory cortex
cortical neurons receive inputs from more than one glomerulus-->allows to integrate inputs from multiple olfactory receptor proteins that can detect the same odorant
35
comparison neurons
respond to a mix of two odorants, but are not stimulated by either of the odorants when present individually
36
why is olfaction unique
doesnt necessarily go through thalamus on the way to 6-layered cortex
37
central projection of olfactory information
mitral cells-->olfactory tract-->olfactory tubercle-->piriform cortex-->entorhinal cortex
38
info to the amygdala
to the hypothalamus | emotional and motivational aspects of odor sensation
39
info to thalamus
goes to frontal lobe | olfactory perceptions and discrimination occurs
40
info to entorhinal cortex
goes to hippocampus | (with amygdala) serves as a mechanism by which we remember odors and specific emotional responses coupled to tehm
41
adrenergic fibers
provide input involved in heightened sense of smell during fear and excitement
42
inputs from olfactory bulb-->locus ceruleus
emotional state influences the perception of odors-->may be a part of increased sensitivity to smell of food when hungry
43
flavor is
information from taste receptors, thermoreceptors, pain receptors, and mechanoreceptors in mucous membranes of mouth and tongue
44
5 groups of taste
``` sweet sour bitter salt umami ```
45
umami
taste of L-glutamate or MSH | helps signal presence of protein-rich foods
46
where are taste receptors located
tongue | back of mouth and pharynx (palate, epiglottis, esophagus)
47
papillae
``` peg like projections covering the tongue 4 types are filoform circumvallate foliate fungiform ```
48
filoform
cover much of surface of tongue | no taste buds
49
circumvallate
have ~7-12 of these round structures across the back of the tongue -250 taste buds each (half of the tastebuds in humans)
50
foliate
arranged in closely packed folds along back edges/side of tongue -often more well developed in children, barely detectable in adults
51
fungiform
scattered across entire surface of the tongue
52
supertasters
increased sensitivity to bitter substances than average individuals --appear to have a higher density of fungiform papillae on their tongue
53
how many taste buds in humans
4000
54
three types of cells in taste buds
support cells basal cells receptor cells
55
basal cells are
progenitor cells that give rise to taste receptor cells
56
receptor cells are
continously turned over average lifetime of 10 days-->unlike olfactory receptor cells, taste receptor cells do not have axons that convey information centrally..they are secondary sensory cels
57
innervation of taste receptors
facial nerve glossopharngeal nerve vagus nerve
58
path of taste buds
facial, glossopharyngeal, vagal-->base of sensory cells-->nucleus of solitary tract-->vpm nucleus of thalamus-->gustatory cortex in temporal lobe, hypothalamus & amygdala
59
circumvallate & foliate innervated by
glossopharyngeal
60
fungiform innervated by
facial
61
Different sensitivity of regions of the tongue
Bitter- near back or base (circumvallate) sour- edges (foliate) sweet and salty- tip- facial
62
salt receptors
voltage insensitive Na channels normly open and some Na ions leak into cell: taste stimuli-->increase in Na ions in extracellular fluid-->increase in leak-->depolarization of taste receptor cell
63
what drug blcosk salt sensitive channels
amiloride
64
sour taste
degree of sourness depends on proton level-->protons open up cation selective ion channel-->cell becomes depolarized
65
sweet receptors
specific GPCR for sweet molecules-->increase phospholipase C-->generation IP3-->release of Ca frm internal stores and transmitter release
66
bitter receptors
involve a second messenger mediated release of Ca internal stores but different receptors than sweet
67
umami
truncated version of metabotropic glutamate receptor (large portion of extracellular domain, including glutmate binding site is msising) -->linked to a second messenger cascade
68
NT and taste
recent evidence that taste receptor cell function and responsiveness are modulated by extrinsic factors, such as NT and hormones, providing a way in which emotional state (hunger) may influence taste responses
69
NT that enhance taste cell responses
5HT | CCK
70
enhance taste cell respnses to NaCl
aldosterone, vasopressin
71
salivation, coughing, gagging pathway
projections to nucleus of solitary tract->VPM of thalamus-->temporal lobe in insula (gustatory cortex)
72
tactile information
gustatory information to insula
73
atrophic rhinitis
reduced olfactory abilities
74
diabetes
reduced olfactory abilities
75
chronic renal failure
reduced olfactory adn gustatory abilities
76
Alzheimer's disease
reduced olfactory abilities (loss of receptor cells)
77
cystic fibrosis
enhnaced olfactory and gustatory abilities
78
epilepsy
enhanced olfactory and gustatory abilities

Neuro (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions