Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy and Physiology > Olfaction and Gustation > Flashcards

Olfaction and Gustation Flashcards

1
Q

Sensation

A
  • conscious/subconscious awareness of changes in internal or external environment
  • components: stimulation of sensory receptor –> transduction of stimulus–> generation of nerve impulses –> integration of sensory input
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Transduction

A
  • receptors change stimuli into electrical event

- stimulus opens/closes ion channels in memrane of receptor –> usually net influx of Na to depolarize membrane

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

Classification of sensory receptors

A

General senses

  • somatic = tactile, thermal, pain, proprioceptive
  • visceral = info about conditions w/in internal organs

Special senses
-smell, taste, vision, hearing, equilibrium/balance

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

Types of sensory receptors

A

Free nerve endings = pain and thermoreceptors

Encapsulated nerve endings = pacinian corpuscles

Separate cells = hair cells, photoreceptors, gustatory receptor cells

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

Generator vs Receptor Potential

A

Generator Potential = produced by free nerve endings, encapsulated nerve endings, and olfactory receptors. When it reaches threshold, it triggers 1+ nerve impulses in the axon of a first-order sensory neuron

Receptor potential = triggers release of neurotransmitter –> postsynaptic potential –> AP

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

Classification of sensory receptors based on stimulus

A 
mechanoreceptors = vibration + movement
Thermoreceptors =temp
Nociceptors = pain
Photoreceptors = light
Chemoreceptors = chems
Osmoreceptors = osmolarity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Receptor Adaptation

A

Tonic receptors = respond to stimulus that requires constant monitoring –> keep making elec signal as long as stimulus persists (e.g. mechanoreceptors monitoring BP)

Phasic Receptors = respond to stimulus CHANGES–> stop signals if stimuls remains constant –> reduced sensitivity (e.g. tactile receptors)

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

Special sense receptor types

A

olfaction and gustation = chemoreceptors
Audition and equilibrium = mechanoreceptors
vision = photoreceptor

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

general senses vs special senses

A

general are simple in structure and scattered thru body

special are anatomically distinct, concentrated in specific locations in head, and involve a complex neural pathway

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

olfaction

A
  • olfactory epithelium (over superior nasal concha) has 10-100 mil receptors
  • olfactory receptor = bipolar neuron with cilia (olfactory hairs which respond to chem stimulation of an odorant molecule)
  • supporting cells provide support and nourishment
  • basal cells = stem cells which replace olfactory receptors every 60 days (RECEPTORS ARE NEURONS)
  • olfactory glands in lamina propria produce mucus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

physiology of olfaction

A

-can detect 10,000 dif odors

Odorant binds to receptor of olfactory hair –> G-prot activation –> activation of adenylate cyclase –> production of cAMP –> opening of Na channels –> inflow of Na (and Ca)–> generator potential –> nerve impulse thru olfactory nerves –> olfactory bulbs –> olfactory tract –> primary olfactory area of cerebral cortex (and limbic system)

Doesn’t go thru thalamus

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

Adaptation and threshold for olfation

A

Fast adaptation – reduced sensitivity occurs quickly

Low threshold – very small quantity required to percieve as an odor

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

Anatomy of Taste buds and papillae

A

-Taste bud = 3 types of epithelial cells (supporting cells, gustatory receptor cells, basal cells)

~50 gustatory cells/taste bud, each with gustatory hair thru taste pore

  • taste buds are on papillae
  • 3 kinds of papillae w/ taste buds (vallate/circumvallate, fungiform, and foliate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

structure of taste bud

A
  • 50-100 lask shaped epithelial cells
  • gustatory cells with micreovilli (hairs)
  • 3 types of gustatory epithelial cells: one releases seratonin; others lack synaptic vessicles, but one releases ATP as a neurotrans

-basal epithelial cells = dynamic stem cells that divide every 7-10 days

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

Tongue papillae

A

Foliate papillae: on sides of tongue –> minimal taste buds and none in adults

Fungiform papillae: on dorsum surface of tongue – taste buds

Vircumvallate papillae: posterior ~10 – taste buds

Filiform papillae = no taste buds, but provide friction

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

physiology of gustation

A

-5 tastes: sweet, sour, salty, bitter, umami

Tastant dissolves in saliva –> plasma membrane of gustatory hair –> receptor potential –> nerve impulse via cranial nerves 7,9, and 10 –> medulla –> thalamus –> primary gustatory area of cerebral cortex

17
Q

Where 5 tastes come from

A 
Sweet = sugar, alcohol, artificial sweeteners
Salt = metal ions (Na+)
Sour = acids (H+)
Bitter = Alkaloids (quinine, nicotine, caffeine)
Umami = AAs, glutamate and aspartate

Most tastes are combos

18
Q

Physiology of salty tastes

A

Sodium ions diffuse thru Na+ channels, resulting in depolarization

19
Q

Physiology of sour taste

A

Hydrogen ions cause depolarization in one of these ways:

  1. enter cell directly thru H+ channels
  2. bind to gated K+ channels, closing the gate and preventing K+ from leaving cell
  3. Open ligand-gated channels for other positive ions
20
Q

Physiology for sweet taste

A

Sugars bind to receptors and cause cell to depolarize using G-prot mechanism

  • G-prot activates adenylate cyclace which makes cAMP
  • cAMP activates kinase that phosphorylates K+ channels
  • K+ channels close, resulting in depolarization
21
Q

Bitter Physiology

A

Bitter tastants bind to receptors and cause depolarization using G-prot mechanism

  • G prot activates phospholipase C, which converts phosphoinositol (PIP2) to inositol triphosphate (IP3)
  • IP3 causes Ca release from intracellular stores an depolarization of cell
22
Q

Umami physiology

A

AAs bind to receptors and cause depolarization with G-prot mechanism

  • G prot activates adenylate cyclase which catylizes conversion of ATP to cAMP
  • cAMP opens CA channels, depolarizing the cell
23
Q

Gustatory Pathway

A
  • sensory neurons from cranial nerve 7 or 9
  • medulla (purpose of this synapse is to stimulate digestion reflexes, like salivary an gastric secretions)
  • thalamus
  • gustatory cortex in insula
  • linked to limbic system (emotional response to tastes)
24
Q

gustatory adaption/threshold

A

rapid adaptation

variation in threshold

  • bitter = lowest = most sensitive
  • sour/umami = medium
  • sweet/salty = highest = least sensitive
25
Q

Taste modifications

A
  • dependent on smell of foods (w/o smell, there’s less taste)
  • temp an texture
  • genetics (PTC in lab or cilantro)
  • Age: lose receptors and sensitivity
  • appearance of food –> color
  • medications/chemotherapy

Anatomy and Physiology (50 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions