Brainscape's Knowledge GenomeTM

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


See full index

OAP Year 1 > Third Test 160404 > Flashcards

Third Test 160404 Flashcards

1
Q

What are the characteristics of Sound (and how are they measured)?

A
  • amplitude or intensity (measured in decibels, dB)
  • frequency or pitch (Hz or kHz or cycles per second)
  • phase (used for direction of sound)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is decibel?

A

Decibels (dB) = 20 x log10 (p1/p2)

Where p1 and p2 are pressures in dyne/cm2

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

Define ‘pure tone’

A

Sound with only one component

Many sounds have regular set of components: eg f, 3f, 5f etc.

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

What is the ‘fundamental’ frequency?

A

The lowest frequency

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

What is ‘harmonics’?

A

Sound of higher integer multiples

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

List components of the outer ear

A
  • pinna (auricle or flap)

- auditory canal

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

Why is the Pinna important?

A

For sound localization

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

List the components of the middle ear

A
  • eardrum (tympanic membrane)

- ossicles (malleus, incus and stapes)

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

Why is the Eustachian (auditory) tube important?

A

It keeps air pressure equal on both sides of the eardrum

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

Sounds waves in outer vs inner ear

A

Outer: in air
Inner: in fluid
The impendance (resistance to compression) of water is much higher than that of air.
Hence without middle ear, 97% of energy would be reflected, but with it only 40% is (so we can hear better)

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

List the components of the inner ear

A
  • cochlea

- vestibular apparatus

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

List events of sound reception in inner ear

A
  • sound travels down auditory canal and hits middle ear, the stapes moves like a piston
  • pressure wave transmitted through oval window of cochlea
  • pressure wave moves basilar membrane - cilia bend on hair cells
  • graded potential occurs with release of neurotransmitter
  • basilar membrane vibrates, tectorial membrane as well but in a different direction - causes bending of hair cells
  • sound to oval window
  • wave travels down basilar membrane and reaches maximum height at some point
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe function of the basilar membrane

A

Is a mechanical frequency analyzer:

  • each location along the membrane is tuned to different frequency due to varying stiffness
  • high frequency peak near base (oval window)
  • low frequency peak near apex (helicotrema)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the innervation of the organ of Corti

A
  • afferent nerve fibers arise from nerve cell bodies within spiral ganglion
  • 95% contact inner hair cells (each of which consists of the sole terminus for up to 10 axons)
  • 5% contact the outer hair cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the hair cells innervated by (in the ear)?

A 
The cochlear (auditory) nerve (branch of 8th CN - vestibulocochlear nerve)
With neuron cell bodies in the spiral ganglion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the action of the cochlear nerve fibers

A

They fire in a phase-locked manner

I.e. Fire at peaks of wave

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

Where does the cochlear nerve project to?

A

To the dorsal and ventral cochlear nucleus in the medulla

- making tonotopic maps here

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

Where does the ventral cochlear nucleus project to?

A

Superior olivary nucleus

  • inputs from both ears are correlated here and sound source is localized
  • it’s here that there’s a response to inter-aural differences and phase differences
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where does the dorsal cochlear nucleus project to?

A

Superior olivary nucleus

- with information about the response to sound pattern (e.g. Frequency modulation

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

Where does the superior olivary nuclei project to?

A

(Via lateral lemmiscus) to inferior colliculus in midbrain
- cells respond to amplitude and frequency modulation, inter-aural amplitude and phase differences, direction of sound motion in space

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

Where does the inferior colliculus project to?

A

Medial geniculate in thalamus

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

Describe sound localization

A

Each neuron on the lateral superior olive receives inputs from both ears

  • ear located on the same side provides excitatory input to dendrites
  • ear located on the opposite side provides an inhibitory input
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe sound localization based on amplitude

A

Sound source in front - excitatory and inhibition is equal

Sound to the side - excitatory and inhibition is unequal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the traveling wave theory (by Georg Von Bekesy

A
  • a sound impulse sends a wave along the basilar membrane.
  • as the wave moves along the membrane it’s amplitude increases until it reaches a maximum, then falls off sharply until the wave dies out
  • where the wave reaches its greatest amplitude is the point at which the frequency of the sound is detected by the ear
  • high frequency = base of cochlea
  • low frequency = apex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

ERG: what does the a-wave measure?

A

The general physiological health of the photoreceptors in the outer retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

ERG: what does the b-waves measure?

A

The health of the inner layers of the retina

  • The ON bipolar cells
  • the muller cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

ERG: what does the c-wave measure?

A

The pigment epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

ERG: what does the d-wave measure?

A

The activity of the OFF bipolar cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

ERG: what does the oscillitatory potentials reflect?

A

The activity in amacrine cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Define electrooculogram (EOG)

A

Electrophysiological test of function of the outer retina and retinal pigment epithelium

  • records change in the electrical potential between the cornea and the ocular fundus during successive periods of dark and light adaptation
  • diagnostic method of the human oculomotor system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Define BEST’s disease

A

Sight loss can be variable but it threatens central vision in one or both eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is Fundus photography?

A

Photograph of interior surface of the eye, including

  • retina
  • optic disc
  • macula
  • posterior pole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is fundus photography used for?

A

Monitoring progression of a disease

Diagnosis of a disease (in combination with retinal angiography)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Describe the properties of a fundus camera

A

Typical camera views 30 to 50 degrees of retinal area, with magnification 2.5x
Allows modification through zoom or auxiliary lenses from 15 degrees (5x magnification) to 140 degrees with wide angle lens (which minifies image by half)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Define sound

A

A temporal modulation of air pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How does the fundus camera work?

A

Observation light is focused via a series of lenses through a donut shaped aperture, then passes through a central aperture from an annulus, before passing through the camera objective lens and through cornea onto the retina.
Light reflected from retina passes through the un-illuminated hole in the donut formed by the illumination system.
Minimal reflections are captured in the image because the light paths of the two systems are independent.
When button is pressed to take a photo, a mirror interrupts the path of illumination system allowing light from flashbulb to pass into the eye.
A mirror also falls in front of the observation telescope, redirecting reflected light onto the capturing medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is fundus autoflourescensce used for?

A

Documenting metabolic changes at the level of retinal pigment epithelium, suggesting areas of high risk for visual function loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What causes fundus autoflourescensce?

A

The light-sensing molecules (retinoids) in the photoreceptors are succeptible to damage and cross-linking. Photoreceptors shed their damaged outer segments which the RPE ingests through phagocytosis. The molecules are stored in liposomes and form lipofuscin (LF).
Age and disease can contribute to a buildup of LF in RPE. LF is made into fluorescence by 500-800 nm wavelengths, they then release a photon of light which is recorded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Define hyperfluorescence

A

Areas of excess lipofuscin accumulation during fundus autoflourescensce will appear hyperfluorescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Define hypofluorescence

A

When RPE cells die or are absent, lipofuscin disappears, leading to hypofluorescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does fluorescein angiography do?

A

Evaluates blood vessels in the eyes with macular or retinal disease.
Used to asses the integrity of the retinal and choroidal vasculature.
Can be used to detect diabetic retinopathy, occlusions, edoema, and tumours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Describe procedure of fluorescein angiography

A

Test requires dilation of the pupils and a small injection of vegetable dye (through an IV needle into a vein in your arm)
A series of pictures are taken in the space of 15-20 mins.
For most patients: no side effects
Some will feel nauseated for a few minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What information does an a-scan ultrasonography give you?

A

Information regarding the density of the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Describe procedure of ophthalmic ultrasonography

A

Uses high-frequency sound waves, transmitted from a probe into the eye.
As the wave strike intraocular structures, they’re reflected back and converted into an electric signal, which is reconstructed as an image and can be used to make a dynamic evaluation of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Describe an a-scan ultrasonography

A

A thin, parallel sound beam is emitted, passes through the eye and images one small axis of tissue

  • the echoes are represented as spikes arising from a baseline.
  • the stronger the echo, the higher the spike
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Describe a b-scan ultrasonography

A

An oscillating sound beam is emitted, passing through the eye and imaging a slice of tissue

  • the echoes are represented as a multitude of dots that together form an image
  • the stronger the echo, the brighter the dot
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What information can a b-scan ultrasonography tell you?

A

It can help you differentiate a posterior detachment (a benign condition) from a more highly reflective retinal detachment (a blinding condition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is OCT?

A

An imaging technique that allows a detailed view of living structures within the eye, non-ivasively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

How does OCT work?

A

Similar to ultrasound b-scan
Uses reflectivity of light instead of sound to produce detailed images (tomograms)
Low-coherent near-infrared light beam split into two
- one beam to a reference mirror, other to the imaged tissue
- back scattered light from both surfaces combine, interference occur and an image is generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What does OCT stand for?

A

Ocular coherence tomography

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is the resolution of an OCT?

A

High resolution 1-10 um

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Define sensation

A

A conscious or unconscious awareness of external or internal stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is sensory input?

A

Sensory impulses reach the CNS and become part of a large pool of sensory input
Each piece of incoming information is combined with other arriving and previously stored information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is sensory modality

A

The property by which one sensation is distinguished from another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

List different types of sensations

A
  • touch
  • pain
  • temperature
  • vibration
  • hearing
  • vision
    Generally each type of sensory neuron can respond to only one type of stimulus
56
Q

What are the two classes of sensory modalities?

A

General senses

Special senses

57
Q

List examples of somatic senses

A
  • tactile sensations (touch, pressure, vibration, itch and tickle)
  • thermal sensations (warm and cold)
  • pain sensations
  • proprioception (awareness of limb and joint position in space)
58
Q

Define visceral senses

A

Provide information about conditions within internal organs

59
Q

Describe the process of sensation

A
  • stimulation of receptor
  • transduction (conversion) of stimulus into a graded potential (vary in amplitude and are not propagated)
  • generation of impulses when graded potential reaches threshold
  • integration of sensory input by the CNS
60
Q

Name a few properties of sensory receptors

A

Demonstrate selectivity (respond to only one type of stimuli)
General sensory receptors (somatic)
- no structural specializations in free nerve endings, provide us with pain, tickle, itch, temperatures,
- some structural specializations in receptors for touch, pressure and vibration
Special sensory receptors (special sense)
- very complex structures - vision, hearing, taste and smell

61
Q

List alternate classifications of sensory receptors

A
  • structural identification
  • type of response to a stimulus
  • location of receptors and origin of stimuli
  • type of stimuli they detect
62
Q

Structural classification of sensory receptors

A

Free nerve endings
- bare dendrites
- pain, temperature, tickle, itch and light touch
Encapsulated nerve endings
- dendrites enclosed in connective tissue capsule
- pressure, vibration, and deep touch
Separate sensory cells
- specialized cells that respond to stimuli
- vision, taste, hearing, balance

63
Q

Classification of sensory receptors by stimuli detected

A 
Mechanoreceptors
- detect pressure or stretch
- touch, pressure, vibration, hearing, proprioception, equilibrium and blood pressure
Thermoceptors detect temperature
Nociceptors detect damage to tissues
Photoreceptors detect light
Chemoreceptors detect molecules
- taste, smell and changes in body fluid chemistry
64
Q

Classification of sensory receptors by response to stimuli

A

Generator potential
- free nerve endings, encapsulated nerve endings and olfactory receptors produce generator potentials
- when large enough, it generates a nerve impulse in a first-order neuron
Receptor potential
- vision, hearing, equilibrium and taste receptors produce receptor potentials
- receptor cells release neurotransmitter molecules on first-order neurons producing postsynaptic potentials
- PSP may trigger a nerve impulse
Amplitude of potentials vary with stimulus intensity

65
Q

Classification of sensory receptors by location

A

Exteroceptors
- near surface of body
- receive external stimuli
- hearing, vision, smell, taste, touch, pressure, pain, vibration, and temperature
Interoceptors
- monitor internal environment (BV or viscera)
- not conscious except for pain or pressure
Proprioceptors
- muscle, tendon, joint, and internal ear
- senses body position and movement

66
Q

Define tactile sensations

A

Touch, pressure, and vibration, plus itch and tickle
Receptors include:
-corpuscles of touch (Meissner’s corpuscles)
-hair root plexus was
-type I (Merkel’s discs)
-type II cutaneous (Ruffini’s corpuscles)
-mechanoreceptors
-lamellated (Pacinian) corpuscles
-free nerve endings

67
Q

What is Meissner’s corpuscle?

A
  • dendrites enclosed in CT in dermal papillae of hairless skin
  • discriminative touch and vibration – rapidly adapting
  • generate impulses mainly at onset of a touch
68
Q

List two types of touch

A

Crude touch

Discriminative touch

69
Q

Define crude touch

A

The ability to perceive that something has simply touched the skin

70
Q

Define discriminative touch

A

(Fine touch) provides specific information about touch sensation such as location, shape, size, and texture of the source of stimulation

71
Q

List two slowly adapting receptors for touch

A

Type I cutaneous mechanoreceptors (tactile or Merkel’s discs

Type II cutaneous mechanoreceptors (end organs or Ruffini)

72
Q

Define Merkel’s disc

A

Flattened dendrites touching cells of stratum basale

Used in discriminative touch (25% of receptors in hands)

73
Q

Define Ruffini’s corpuscle

A

Found deep in dermis of skin

Detect heavy touch, continuous touch and pressure

74
Q

Define pressure (as a sensation)

A

Sustained sensation that is felt over a larger area than touch

  • generally result from stimulation of tactile receptors in deeper tissues and are longer lasting and have less variation in intensity than touch sensations
  • receptors for pressure are type II cutaneous
  • like corpuscles of touch, lamellated corpuscles adapt rapidly
75
Q

Define vibration as a sensation

A

Result from rapidly repetitive sensory signals from tactile receptors
- receptors are corpuscles of touch and lamellated corpuscles, which detect low frequency and high frequency vibrations, respectively

76
Q

Define Pacinian corpuscle

A
  • onion-like connective tissue capsule enclosing a dendrite
  • found in subcutaneous tissues and certain viscera
  • sensations of pressure or high-frequency vibration
77
Q

What kind of receptors are tickle and itch receptors?

A

Free nerve endings

78
Q

Itch and tickle sensations

A
  • experienced when mild stimulation of the pain nerve endings occurs
  • also specific nerve endings for itch sensation
  • transmitted by group C unmyelinated nerve fibers
  • histamine produces itch while pain signals suppress it
79
Q

Define hair root plexus

A

Free nerve endings found around follicles, detects movement of hair

80
Q

Define thermal sensations

A
  • free nerve endings with 1mm diameter receptive fields on the skin surface
    • cold receptors in stratum basale 10-40.5 degrees C
    • warm receptors in dermis 32-47.8 degrees C
  • both adapt rapidly at first, but continue to generate impulses at a low frequency
  • pain is produced below 10 and over 40.5 degrees C
81
Q

Define proprioceptive sensations

A

Receptors are located in skeletal muscles, tendons, in and around joints, and in the internal ear convey nerve impulses related to:
- muscle tone
- movement of body parts
- body position
This awareness of muscles, tendons, joints, and of balance or equilibrium is provided by the proprioceptive or kinesthetic sense.
Information is sent to cerebellum and cerebral cortex

82
Q

Muscle spindles role in sensation

A

Stretching of the muscle stretches the muscle spindles sending sensory information back to the CNS
They monitor changes in muscle length
Brain regulates muscle tone by controlling gamma fibers

83
Q

Golgi tendon organs

A

Found at junction of tendon and muscle
Consists of an encapsulated bundle of collagen fibers laced with sensory fibers
When tendon is overly stretched, sensory signals head for the CNS and resulting in the muscle’s relaxation

84
Q

Joint receptors

A

Ruffini’s corpuscles
- found in joint capsule
- respond to pressure
Pacinian corpuscles
- found in connective tissue and around the joint
- respond to acceleration and deceleration of joints

85
Q

What do somatosensory pathways do?

A

Send information from somatic receptors to the primary somatosensory area in the cerebral cortex
Pathways consist of three neurons (first order, second order and third order)
Axon collaterals of somatic sensory neurons simultaneously carry signals to the cerebellum and the reticular formation of the brain stem

86
Q

Somatosensory pathways:

First order neuron

A

Conduct impulses to the CNS (brain stem or spinal cord)

- either spinal or cranial nerves

87
Q

Somatosensory pathways:

Second order neurons

A

Conduct impulses from brain stem or spinal cord to thalamus

- cross over to opposite side of the body

88
Q

Somatosensory pathways:

Third order neuron

A

Conducts impulses from thalamus to primary somatosensory cortex (postcentral gyrus of parietal lobe)

89
Q

What impulses are conducted along the posterior column-medial lemniscus pathway to the cortex?

A
  • fine touch
  • stereognosis
  • proprioception
  • vibration sensations
90
Q

Describe the anterolateral pathways to the cortex

A
  • 3-neuron pathway
  • carry mainly pain and temperature impulses
  • relay sensations of tickle and itch and some tactile impulses
91
Q

What are the major routes by which proprioceptive impulses reach the cerebellum?

A

Posterior spinocerebellar

Anterior spinocerebellar tracts

92
Q

What are the impulses conducted by the cerebellum critical for?

A

Posture
Balance
Coordination of skilled movements

93
Q

List three rapidly adapting receptors

A

Smell
Pressure
Touch
- specialized for detecting changes

94
Q

List two slowly adapting sensory receptors

A

Pain
Body position
- nerve impulses continue as long as the stimulus persists - pain is not easily ignored

95
Q

Define perception

A

The conscious awareness and interpretation of a sensation

  • precise localization and identification
  • memories of our perceptions are stored in the cortex
96
Q

What are pain receptors?

A

(Nociceptors) are free endings that are located in nearly every body tissue (except the brain)
-adaptation is slight if it occurs at all

97
Q

List different types of pain

A 
Fast pain (acute)
Slow pain (chronic)
Somatic
-Superficial
-Deep
Visceral 
Referred pain
98
Q

Describe fast pain (acute)

A
  • occurs rapidly after stimuli
  • sharp pain like needle puncture or cut
  • not felt in deeper tissues
  • larger A nerve fibers
99
Q

Describe slow pain (chronic)

A
  • begins more slowly and increases in intensity
  • aching or throbbing pain of toothache
  • in both superficial and deeper tissues
  • smaller C nerve fibers
100
Q

Describe superficial pain

A

Somatic pain that arises from the stimulation of receptors in the skin

101
Q

Describe deep pain

A

Somatic pain that arises from skeletal muscle, joints and tendons

102
Q

Describe visceral pain

A

Usually felt in or just under the skin that overlies the stimulated organ
- localized damage (cutting) intestines may cause no pain, but diffuse visceral stimulation can be severe
(Eg distension of a bile duct from a gallstone, or of the urethral from a kidney stone)

103
Q

Describe referred pain

A

When pain is felt in a surface area far from the stimulated organ
A version of visceral pain
E.g. Heart attack is felt in skin along left arm since both are supplied by spinal cord segment T1-T5

104
Q

Examples of pain relief

A
  • aspirin and ibuprofen block formation of prostaglandins that stimulate nociceptors
  • novocaine blocks conduction of nerve impulses along pain fibers
  • morphine lessen the perception of pain in the brain
105
Q

What are the two chemical senses?

A

Olfaction (smell) and gustation (taste)

106
Q

Define chemical senses

A

Interaction of molecules with receptor cells

Both smell and taste project to cerebral cortex and limbic system (evoke strong emotion)

107
Q

Describe the anatomy of olfactory receptors

A
  • bipolar neurons that are in the nasal epithelium in the superior portion of the nasal cavity
  • first-order neurons of the olfactory pathway
  • supporting cells are epithelial cells of the mucous membrane lining the nose
  • basal stem cells produce new olfactory receptors
108
Q

What three types of cells does the olfactory epithelium consist of?

A

Olfactory receptor
- bipolar neuron with cilia (olfactory hairs)
- there are 10-100 million of the in the nose that respond to odourant molecules
Supporting cells
- provide support and nourishment
Basal cells
- stem cells that replace olfactory receptors

109
Q

How many different odours can the olfactory apparatus detect?

A

About 10,000

110
Q

List the intracellular events that occur when we smell

A
  • odourant binds to receptor of an olfactory hair
  • initiates events through a G-protein and a 2nd messenger
  • production of cAMP
  • opening of Na+ channels
  • inflow of Na+
  • generator potentials
    (- nerve impulses travel through 2 olfactory nerves
  • olfactory bulbs
  • olfactory tract
  • primary olfactory area in the temporal lobe of the cortex)
111
Q

Olfactory supporting cells and glands are innervated by:

A

The facial (VII) nerve

  • provides parasympathetic motor innervation to lacrimal glands and the mucous membranes in the nasal cavity
  • this is why certain smells will make our nose run and cause us to produce tears
112
Q

What is hyposmia?

A

A reduced ability to smell
- affects half of those over age 65
- affects 75% of those over age 80
Can be caused by neurological changes, drugs, or the effects of smoking

113
Q

Where does conscious awareness of smell begin?

A

In the primary olfactory area of the temporal lobe

114
Q

Where does identification of smell occur?

A

In the frontal lobe

115
Q

Define adaption

A

Decreasing sensitivity

116
Q

Comment on olfactory adaption

A

It is rapid
- 50% in 1 second
- complete in 1 minute
Low threshold - only a few molecules need to be present in order for us to feel the smell

117
Q

What is vital in order for us too detect a taste?

A

The molecules must be dissolved

118
Q

What different stimuli classes of taste is there?

A 
Sour
Sweet
Bitter
Salty
Umami - protein-rich foods
119
Q

List different aspects of flavour

A 
Taste
Aroma
Temperature
Texture
Appearance of food
120
Q

Define papillae

A

Specialized portions of the tongue associated with different types of taste buds

121
Q

List the four major types of papillae

A 
They're names after their shape:
Vallate
Fungiform 
Foliate
Filiform
122
Q

What papillae are taste buds associated with?

A

Vallate
Fungiform
Foliate

123
Q

Describe filiform papillae

A

The most numerous papillae on the surface of the tongue
Have NO taste buds
Contain tactile receptors
Increase friction between tongue and food, making it easier to move food in the oral cavity

124
Q

Describe vallate papillae

A

Largest
Least numerous
8-12 form a V-shaped row along the border between anterior and posterior parts of the tongue

125
Q

Describe fungiform papillae

A

Scattered irregularly over entire superior surface of the tongue
Appear as small red dots among the more numerous filiform papillae
Mushroom shaped
Containing about 5 taste buds each

126
Q

Describe foliate papillae

A

Distributed in folds on the sides of the tongue
Contain most sensitive taste buds
Most in young children, decrease with age
Located mostly posteriorly in adults

127
Q

Define tastants

A

Chemicals that stimulate gustatory receptor cells
Once a tastant is dissolved in saliva, it can make contact with the plasma membrane of the gustatory hairs (= sites of taste transduction)
Result in receptor potential stimulating exocytosis of synaptic vesicles from the gustatory receptor cell
Neurotransmitters trigger nerve impulses in the first-order sensory neurons that synapse with gustatory receptor cells

128
Q

How many gustatory receptors make up a taste bud?

A

About 50

129
Q

What is the lifespan of a gustatory receptor cell?

A

About 10 days

130
Q

Describe the anatomy of a taste bud

A

Consist of 50 receptor cells, surrounded by supporting cells
A single gustatory hair projects upward through the taste pore
Basal cells develop into new receptor cells every 10 days

131
Q

How long does complete taste adaptation take?

A

1-5 minutes

132
Q

List the cranial nerves in which first-order gustatory fibers are found

A

V
VII (facial) serves anterior 2/3 of tongue
IX (glossopharyngeal) serves posterior 1/3 of tongue
X (vagus) serves palate and epiglottis

133
Q

Describe the gustatory pathway

A

Via cranial nerves to thalamus or limbic system and hypothalamus
To primary gustatory area on parietal lobe of cerebral cortex
- provides conscious perception of taste

134
Q

List the motor control hierarchy

A

Cerebral cortex
Brain stem
Spinal cord (direct pathway)

135
Q

Give a brief summary of the somatic motor system

A

Motor commands from brain travel down spinal cord
Signal relayed by motor neuron in ventral horn
Muscle contracts
Proprioceptors in muscles and joints send feedback to cord and brain
Ongoing motor command altered

OAP Year 1 (3 decks)

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