Brainscape's Knowledge GenomeTM

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


See full index

PHA 511 > 4a. Sensory Systems > Flashcards

4a. Sensory Systems Flashcards

1
Q

Taste Receptors

A

Characteristic distribution, regions are a mixture

Some overlap in response

Taste is a combination of the categories

Tongue also has mechanoreceptors and thermoreceptors

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

Taste Receptors: Categories

A 
sour (foliate papillae)
sweet (fungiform papillae)
salty (fungiform papillae)
bitter (circumvallate papillae)
umami (fungiform papillae)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Taste Buds

A

Location of taste receptors

On tongue and other areas of mouth

Grouped in each of 3 types of papillae on tongue

1 bud = ~50 receptors

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

Taste Receptor: Hairs

A

Project into taste pore - pick up taste stimuli

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

Taste Transduction

A
  1. Dissolved substances initiate transduction (substance must be dissolved in saliva to come in contact with R)
  2. Depolarizing R potentials
  3. Some taste R have voltage gated Na channels, make AP and release ATP
  4. Other taste R have voltage gated Ca channels and release vesicles of ATP (ATP release as NT - depolarizes primary afferent nerve ending)
  5. Peripheral endings of CN VII, IX, X depolarize - fire faster
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

CN for Conscious Perception of Taste

A

CN VII Facial
CN IX Glossopharnygeal
CN X Vagus

Mostly 7 and 9

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

Taste Receptors: Modified Epithelial Cells

A

Depolarizing receptor potentials –> release of NT ATP –> AP in primary neuron

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

Salt

A

NaCL

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

Sour

A

H+ in citric acid

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

Sweet

A

Sugar (glucose)

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

Bitter

A

Alkaloids (quinine)

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

Umami

A

L glutamate

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

Taste Pathways

A
  1. taste receptors
  2. cranial nerves (1 neuron)
  3. brainstem - nucleus solitarius (2 neuron)
  4. Thalamus (3 neuron)
  5. Gustatory cortex - insula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Limbic System

A

Provides affective dimension of taste (emotional context)

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

Olfactory Receptors

A

primary afferent neurons - not a separate cell

In olfactory mucosa

Odorant molecules bind to receptors in cilia in mucus layer

CN I (olfactory) goes through cribriform plate to connect with olfactory receptor in olfactory mucosa

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

Olfactory Transduction

A
  1. Olfactory R binds odorant molecules –> activates G protein
  2. Increase in intracellular cAMP
  3. cAMP gated cation channels open - Ca2+ enters
  4. Depolarization - Cl- leaves through Ca2+ gated Cl- channels
  5. Depolarization travels to initial segment of olfactory nerve
  6. AP generated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Axons from olfactory receptors leave olfactory epithelium …

A

Travel ventrally to olfactory bulb - pass through cribriform plate

fractures of cribriform plate can sever olfactory neurons –> disorders

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

Odor Discrimination

A

Enabled by variations in receptor molecule

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

Olfactory Pathway

A
  1. olfactory receptors (1 neuron: CNI (olfactory))
  2. olfactory bulb: apical dendrites of mitral cells (2 neuron)
  3. primary olfactory cortex (piriform cortex)

Also project to amygdala, limbic system

NO RELAY IN THALAMUS

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

Outer Ear (anatomy, function)

A

Direct sound through ear canal to tympanic membrane

helix
auricle
auditory canal
earlobe

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

Middle Ear (function, anatomy)

A

Begins process of transmitting vibrations to inner ear

tympanic membrane?
ossicles (stapes, incus, malleus)

22
Q

Inner Ear (function, anatomy)

A

Transmits sound and balance information to brain

semicircular ducts?
vestibular nerve
cochlear nerve
cochlea
round window?
tympanic cavity?
tensor tympani muscle
auditory tube
23
Q

Cochlea

A

Contains receptor cells

Coils 2.5 around modiolus (bony pillar)

3 chambers:

  • scala tympani
  • scala media
  • scala vestibuli

2 fluids:

  • perilymph
  • endolymph

Hair cells sit in cochlear duct

24
Q

Perilymph

A

Fills scala vestibuli and scala tympani (continuous)

Similar composition to ECF

Movement –> bulges in cochlear duct –> activation of basilar membrane

25
Q

Endolymph

A

Fill scala media (cochlear duct)

Chemically similar to ICF (K+ rich)

Produced continuously via active pumping mechanism –> positive electrical potential inside ear (+80mV)

26
Q

Membranes of Cochlea

A
  • Reissner’s/vestibular membrane
  • Basilar membrane
  • Tectorial membrane
27
Q

Reissner’s Membrane

A

Roof of cochlear duct

28
Q

Basilar Membrane

A

Fibrous floor of cochlear duct

Supports organ of corti

Near oval window: narrow, thick

Near cochlear apex: wider, thinner

29
Q

Tectorial Membrane

A

Overhanging membrane of organ of corti

In contact with stereocilia of hair cells

30
Q

Role of Sense of Hearing

A

Translate pressure waves of perilymph and endolymph to electrical signal and acoustic sensation

31
Q

Bending of cilia produces change in K+ conductance

A

Toward kinocilium: increases K+ influx

Away from kinocilium: decreases K+ influx

Kinocilium = tallest sterocilia

32
Q

Basilar Membrane: Fibers

A

Span the width like the strings of a harp

Near oval window: short, stiff
-resonate with HIGH frequency waves

Near cochlear apex: longer, floppier
-resonate with lower frequency waves

33
Q

Sound

A

Pressure disturbance originated from a vibrating object

Propagated by molecules of medium (air, liquid)

Normally manifests as pressure or sound wave

34
Q

Frequency

A

Number of sound waves that pass a given point in a given time

Hertz

Shorter wavelength = high frequency

35
Q

Pitch

A

Our ears perceive different frequencies as pitch

higher frequency = higher pitch

ability to distinguish pitch and loudness depends on ability of cochlea to respond differently to vibrations of different amplitude and frequency

36
Q

Tuning Fork

A

Pure sound - single frequency

Most sounds are a mixture of frequencies

37
Q

Place Coding

A

Frequency sensitivity of IHCs depends on their position along basilar membrane of cochlea

38
Q

Loudness

A

An increase in AP firing

Related to amplitude of sound waves

Measure of sound intensity

Decibels

39
Q

Severe Hearing Loss

A

Frequent/prolonged exposure to sound greater than 90 dB

40
Q

Sound source directly in front, in back, over midline of head…

A

Intensity and timing cues will be the same for both ears

41
Q

Sound coming from one side…

A

Nearer hair cells activated:

  • slightly earlier
  • more vigorously
42
Q

Superior Olivary Nucleus

A

Functions in biaural hearing

Compares signals from R and L ear to identify direction from which a sound is coming

43
Q

Conductive Deafness

A

BC>AC

Sound vibrations don’t go from air to ossicles as well as they should (loss of air conduction)

Effects auditory canal and middle ear

44
Q

Conductive Deafness: Causes

A

Ear wax buildup
Fluid buildup from infection
Puncture of eardrum

45
Q

Conductive Deafness: Results

A

Loss of loudness
Loss of clarity
Sounds are weak, muffled, distorted

46
Q

Nerve Deafness

A

Sensorineuronal

Both air and bone conduction decreased

Auditory nerve damage (loss of air and bone conduction)

Effects cochlea, nerve, cochlear nucleus

47
Q

Nerve Deafness: Causes

A

Ototoxic drugs
Prolonged exposure to loud sounds
Inner ear infections

48
Q

Rinne Test

A

Use a tuning fork to determine air conduction (AC) and bone conduction (BC)

49
Q

Normal Hearing in Adults

A

0-25 dB

50
Q

Most Important Frequencies for Speech

A

250-6000 Hz

51
Q

Presbycusis

A

Gradual loss of hearing associated with aging

Due to gradual cumulative loss of hair cells and neurons

52
Q

Presbycusis: Loss

A

Loss of ability to hear consonants

Loss of high frequency sounds

Difficulty screening out background noise

PHA 511 (7 decks)

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