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A&P I > Exam 7 Senses #1-107 > Flashcards

Exam 7 Senses #1-107 Flashcards

1
Q

is the conscious or subconscious awareness of external or internal stimuli

A

Sensation

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2
Q

Components of the central nervous system receive sensory impulses from receptors throughout the body

Impulses to lower parts of the CNS elicit simple responses, such as __ __

A

various reflexes

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3
Q

Impulses that reach the ___ provide a crude awareness of the location and type of sensation

A

Thalamus

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4
Q

Impulses that reach the ___ ___ enable the precise location of the stimulus, as well as the type of stimulus

A

cerebral cortex

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5
Q

is the conscious awareness and interpretation of the meaning of sensations

A

Perception

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6
Q

There is no ____ of sensory impulses that do not reach the thalamus and cerebral cortex: blood pressure and carbon dioxide concentration, for example

A

perception

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7
Q

Whereas nerve impulses do provide the sensation of such stimuli as blood pressure and CO2 concentration, there is no perception of them since they do not reach the ___ ___

A

Cerebral cortex

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8
Q

A __ __ is a unique type of sensation: touch, pain, vision, hearing

A

sensory modality

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9
Q

An individual sensory neuron carries information for only one type of modality
Sensory modalities are grouped into two classes

A
  1. General senses

2. Special senses

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10
Q

Somatic senses
Visceral senses

are included as what type of senses?

A

General Senses

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11
Q

Tactile sensations: touch, pressure, vibration, itch, tickle

Thermal sensations: warm, cold

Pain sensations

Proprioceptive sensations

Dynamic sensations (movements of limbs and head)

A

Modalities of the general senses include

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12
Q

____ sensations provide information about conditions within internal organs. ____ sensation is usually not appreciated at the conscious level of awareness other than as “feeling good” or “feeling bad.”

A

Visceral

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13
Q

Someone who is in the initial stages of a heart attack will often vaguely “not feel good.” They will not feel actual pain until later when the ____ pain becomes so intense that it rises to the level of consciousness

A

Visceral

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14
Q

Special senses comprises the modalities of:

A 
Smell 
Taste 
Vision
Hearing 
Equilibrium
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15
Q

The first step in the process of sensation is activation of a sensory receptor by a stimulus

Sensory receptors comprise either
specialized cells or the dendrites of a sensory neuron

Each sensory receptor monitors one (and only one) type of stimulus to which it is sensitive, and responds weakly, if at all, to other kinds of stimuli

A

This is selectivity

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16
Q

Stimulation of the sensory receptor
Transduction of the stimulus
Generation of impulses
Integration of sensory input

A

Events required for sensation

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17
Q

Events required for sensation:

A

Stimulation of the sensory receptor

Transduction of the stimulus

Generation of impulses

Integration of sensory input

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18
Q

The stimulus must occur within the receptive field of the ___, which is the body region where stimulation elicits a response

A

receptor

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19
Q

____ is the conversion of stimulus energy into electrical energy

A

Transduction

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20
Q

The sensory receptor transduces energy in a stimulus into a ___ ___

A

graded potential

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21
Q

Graded potentials vary in amplitude depending on the strength of the stimulus

Graded potentials are not ___

A

propagated

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22
Q

Because of ____, each type of sensory receptor transduces only one kind of stimulus

A

selectivity

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23
Q

Graded potentials that ___ __ ___ in a sensory neuron trigger one or more nerve impulses that propagate toward the central nervous system

A

sum to threshold

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24
Q

Sensory neurons that conduct impulses from the PNS into the CNS are termed __ __ __

A

first-order neurons

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25
Q

Specific regions of the CNS receive and integrate sensory nerve impulses

Conscious sensations or perceptions are integrated in the ___ __

A

cerebral cortex

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26
Q

Microscopic appearance
Origin of stimuli, and consequent location of the receptor
Type of stimulus detected

A

sensory receptor classification

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27
Q

Bare dendrites
No structural specialization microscopically
Pain, thermal, tickle, itch, some touch

A

Free nerve endings

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28
Q

Dendrites are enclosed in a connective tissue capsule
Capsule enhances sensitivity or specificity of the receptor
Pressure & vibration (lamellated), some touch (Meisner)

A

Encapsulated nerve endings

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29
Q

Sensory receptors for certain special senses are specialized, separate cells
The specialized cell synapses with first-order sensory neuron
Hearing and equilibrium hair cells (inner ear), photoreceptors (retina), gustatory receptors (taste buds)

A

Separate cells

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30
Q

Two different kinds of graded potentials are produced by sensory receptors

A
  1. generator potentials

2. receptor potentials

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31
Q

Amplitude of both types of potentials varies directly with the ____ of the stimulus

A

intensity

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32
Q

Generator potentials are produced by dendrites of

A

Free nerve endings
Encapsulated nerve endings
Receptive part of olfactory receptors

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33
Q

The sensory receptor is the first-order neuron; they are one and the same

A sufficiently large generator potential will generate an __ __

A

action potential

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34
Q

Free nerve endings are bare dendrites of_____. They have no apparent structural specialization. This example shows a cold-sensitive receptor.

A

first-order neurons

slide 18 pic

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35
Q

____ nerve endings have dendrites of first-order neurons surrounded by a specialized capsule. This example shows a lamellated corpuscle.

A

encapsulated

slide 19 pic

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36
Q

Receptor potentials are produced by

A

Hair cells of the inner ear (both equilibrium and hearing)
Gustatory receptors (taste)
Photoreceptors (sight)

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37
Q

The receptor potential triggers release of ______, which diffuses across the synaptic cleft and produces a postsynaptic potential (PSP) in the first-order neuron

The sensory receptor is not the first-order neuron

The PSP may in turn trigger one or more nerve impulses

A

neurotransmitter

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38
Q

Specialized receptor cells are separate and distinct from the first-order neuron. There is a ____ between the receptor and the first-order neuron. This example shows a taste receptor.

A

synapse

slide 21 pic

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39
Q

Located at or near body surface
Provide information about external environment
Sight, odor, taste, touch, pressure, vibration, thermal, pain

A

Exteroceptors

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40
Q

Interoceptors AKA:

A

AKA visceroceptors

or is it velociraptor..

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41
Q

Located in blood vessels, visceral organs, muscles, & nervous system
Provide information about internal environment
Impulses usually not consciously perceived

A

Interoceptors

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42
Q

Located in muscles, tendons, joints, inner ear

Provide information about body position, muscle length and tension, position and motion of joints, and equilibrium

A

Proprioceptors

proprio = one’s own

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43
Q

mechanical pressure, touch sensations, pressure, vibration, proprioception, hearing, equilibrium, stretching of blood vessels and internal organs

A

Mechanoreceptors

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44
Q

changes in temperature

A

Thermoreceptors

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45
Q

physical or chemical damage to tissue (pain)

A

Nociceptors

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46
Q

detect light that strikes the retina

A

Photoreceptors

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47
Q

chemicals in mouth (taste), nose (smell) and body fluids

A

Chemoreceptors

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48
Q

osmotic pressure of body fluids

A

Osmoreceptors

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49
Q

Most sensory receptors exhibit ____, which is a decrease in the generator potential or receptor potential amplitude when exposed to a stimulus that is applied at a constant level over a reasonably long term

A

adaptation

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50
Q

Because of _____, the perception of a sensation may fade or disappear, even though the true magnitude of the stimulus has not changed

A

adaptation

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51
Q

Receptors vary in how quickly they adapt

Rapidly adapting receptors
Adapt very quickly
Are specialized for signaling changes in a stimulus

Examples:

A

touch, pressure, smell

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52
Q

Slowly adapting receptors
Adapt slowly
Continue to trigger nerve impulses as long as the stimulus persists

Examples:

A

pain receptors, proprioception, chemical composition of the blood

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53
Q

____ sensations arise from stimulation of sensory receptors embedded in the skin or subcutaneous layer, in mucous membranes, muscles, tendons, joints, and inner ear

Those ____ sensations that arise from stimulating the surface of the skin are termed cutaneous sensations

A

Somatic

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54
Q

Somatic sensations have four modalities:

A

Tactile
Thermal
Pain
Proprioceptive

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55
Q

Tactile sensations comprise:

A 
Touch 
Pressure 
Vibration 
Itch 
Tickle
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56
Q

____ sensations arise to a great degree by activation of the same structural type of receptor

Free nerve endings: itch, tickle

Encapsulated nerve endings: touch, pressure, vibration

A

Tactile

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57
Q

____ are usually due to stimulation of tactile receptors in the skin or subcutaneous layer

A

Touch sensations

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58
Q

is the ability to perceive that something has contacted the skin, but its location, shape, size, and texture can not be ascertained

A

Crude touch

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59
Q

provides specific information about the location that is touched, and the shape, size, and texture of the source of stimulation

A

Fine touch

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60
Q

____ is a sustained sensation that is felt over a larger area than touch

It occurs with deformation of deeper tissues than does touch, hence some of the receptors for pressure are deeper

A

Pressure

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61
Q

Sensations of _____ result from rapid and repetitive sensory signals from tactile receptors

A

vibration

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62
Q

Corpuscles of touch (___ ___), which detect lower-frequency vibrations

A

Meissner’s corpuscles

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63
Q

Lamellated corpuscles (___ ___), which detect higher-frequency vibrations

A

Pacinian corpuscles

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64
Q

___ sensations result from stimulation of free nerve endings by certain chemicals

May be associated with a local inflammatory response

A

Itch

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65
Q

____ sensations are thought to arise from free nerve endings and lamellated corpuscles

A

Tickle

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66
Q

Thermal sensations comprise

A

Coldness

Warmth

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67
Q

____ are unspecialized free nerve endings that respond to absolute and relative changes of temperature, primarily within the innocuous range

They are located in the skin, cornea, tongue, and bladder

Each sensation is mediated by different specific receptors

A

Thermoreceptors

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68
Q

Pain receptors are free nerve endings found in every tissue of the body except the ____

A

brain

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69
Q

Pain receptors are termed _____, they exhibit very little adaptation

A

Nociceptors

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70
Q

Nociceptors can be activated by intense thermal, mechanical, or chemical stimuli

Tissue irritation or injury releases chemicals that stimulate nociceptors

A

Kinins
Prostaglandins
Potassium ions

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71
Q

___ are polypeptides that induce vasodilation and increased blood vessel permeability, and serve as chemotactic agents for phagocytes. They are formed in blood from inactive precursors called kininogens

A

Kinins

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72
Q

____ are lipids that intensify the effects of histamine and kinins, and stimulate the emigration of phagocytes through capillary walls. They are released by damaged cells.

A

Prostaglandins

73
Q

Kinins affect some nerve endings, causing much of the pain associated with inflammation, and ____ intensify and prolong the pain.

Persistence of pain after the stimulus is removed occurs because the pain-mediating chemicals linger

A

Prostaglandins

74
Q

Two types of pain:

A

Fast

Slow

75
Q

Types of pain differentiated based on:

A

Types of nerve fibers that propagate the impulses (hence the speed of propagation)
Where in the body the particular type of pain can occur

76
Q

Perception of pain occurs very rapidly

Propagated along medium-diameter, _____ __ __

Also termed acute, sharp, or pricking pain

Not felt in deeper tissues of the body

Examples:
Needle puncture
Knife cut

A

myelinated A fibers

77
Q

Perception of pain occurs more slowly—a second or more after the stimulus is applied

Propagated along small-diameter, ___ __ __

Also termed chronic, burning, aching, or throbbing pain, it may be excruciating

Felt in both the skin, deeper tissues of the body, and internal organs

Example: toothache

A

Unmyelinated C fibers

78
Q

is pain that arises from stimulation of receptors in the skin

A

Superficial somatic pain

79
Q

is due to stimulation of receptors in skeletal muscles, joints, tendons, and fascia

A

Deep somatic pain

80
Q

results from stimulation of nociceptors in visceral organs

A

Visceral pain

81
Q

Visceral pain may seem to arise in or just deep to the skin that overlies the stimulated organ

The phenomenon is called ?

A

referred pain

82
Q

___ __ occurs when nerve fibers from regions of high sensory input (such as the skin) and nerve fibers from regions of normally low sensory input (such as the internal organs) happen to converge on the same levels of the spinal cord

A

Referred pain

83
Q

Pain of a heart attack may be felt in the skin over the heart and along the left arm because sensory fibers from the heart, the skin over the heart, and the skin along the medial aspect of the left arm enter the same spinal cord segments

A

slide 40

84
Q

___ is relief from pain

A

Analgesia

85
Q

Some analgesic drugs block formation of ____, which stimulate nociceptors (aspirin, ibuprofen)

A

prostaglandins

86
Q

Local anesthetics block conduction of nerve impulses by preventing opening of ________ (Novocain™)

A

voltage-gated Na+ channels

87
Q

Morphine and other opiate drugs alter the quality of pain perception in the brain; pain is still sensed, but it no longer is ____

A

noxious

88
Q

Amputees may still experience sensations such as itching, pressure, tingling, or pain as if the limb were still there

This is termed ?

A

Phantom limb sensation

89
Q

Possible explanations:
Cerebral cortex interprets impulses arising in the proximal portions of sensory neurons that previously carried impulses from the limb as still coming from the nonexistent limb

Neurons in the brain generate sensations of body awareness, including those neurons that previously received sensory impulses from the missing limb, thereby giving rise to false sensory perceptions

A

Phantom limb sensation

90
Q

Proprioceptive sensations arise in receptors termed ____, allowing us to know where our head and limbs are located and how they are moving even without looking at them
_____ adapt slowly, and then only slightly, so they provide continuous information to the brain

A

Proprioceptors

91
Q

Proprioceptors embedded in muscles (especially postural muscles) and tendons provide information regarding:

A 
degree of muscle contraction
amount of tension on tendons 
position of joints 
relative rates of movement of body parts 
weights of objects
92
Q

Hair cells of the vestibular apparatus in the inner ear are ____ that monitor the orientation and position of the head

A

proprioceptors

93
Q

Types of proprioceptors discussed:

A

Muscle spindles
Tendon organs
Joint kinesthetic receptors

94
Q

are proprioceptors in skeletal muscles that participate in stretch reflexes
Their function is to measure muscle length—how much a muscle is being stretched
They are slowly adapting

A

Muscle spindles

95
Q

Either sudden or prolonged stretching of the muscle will stimulate the muscle spindle
By adjusting how vigorously a muscle spindle responds to stretching, the brain sets an overall level of ___ __ (the small degree of contraction that is present when a muscle is at rest)

A

muscle tone

96
Q

Muscle spindles are interspersed among ordinary skeletal muscle fibers, and aligned parallel to them
The concentration of muscle spindles varies with the particular muscle

A

Muscles requiring finely controlled movements have numerous muscle spindles (greater density)

Muscles involved in coarser movements have fewer (lesser density)

The small skeletal muscles of the middle ear have very few muscle spindles (at one time, it was thought they had none)

97
Q

____ are located at the junction of a tendon and a muscle

They provide information about changes in muscle force
They are slowly adapting

____ protect tendons and their associated muscles from damage due to excessive tension

A

Tendon organs

98
Q

The term ____ does not refer to a particular kind of receptor, but rather to a particular function, which is providing information about parameters associated with the movement (kinesis) of synovial joints

A

joint kinesthetic receptor

99
Q

joint kinesthetic receptor

The parameters include:

A 
Pressure
Changes in velocity
-acceleration
-deceleration
Tension

The receptors are located in and around the articular capsule of synovial joints

100
Q

____ (sense of smell) and ____ (sense of taste) are called the chemical senses since they are stimulated by chemicals, the molecules of which interact with receptors to produce a generator potential (___) or receptor potential (___)

A

Olfaction

Gustation

101
Q

These two senses work together—when you have a cold, so that you cannot smell anything, food does not taste as good because the sense of smell enhances the sense of taste
In both senses, the stimulating molecules must be dissolved to be perceived
___ is much more sensitive than taste to the same chemical

A

Olfaction

102
Q

Millions of olfactory receptors are present in a little less than 1 in^2 of olfactory epithelium, which is in the ____ part of the nasal cavity

A

superior

103
Q

The olfactory epithelium is a pseudostratified ciliated columnar epithelium consisting of three kinds of cells:

A

Olfactory receptors

Supporting cells (AKA sustentacular cells)

Basal stem cells

104
Q

Olfactory receptors are ____ neurons that are the first-order neurons of the olfactory pathway

A

bipolar

105
Q

Each olfactory receptor has a/an

A

axon ending in the olfactory bulb
knob-shaped dendrite
cilia projecting from the dendrite

chemical slide 5 pic

106
Q

The cilia projecting from the dendrites of the olfactory receptor cells are termed _____

They are the sites of olfactory transduction (conversion of stimulus energy into a graded potential in a sensory receptor)

A

olfactory hairs

chemical slide 6 pic

107
Q

Odorants are chemicals that can stimulate the olfactory hairs, which means that odorants are chemicals that have an odor
Olfactory receptors respond to the chemical stimulation of an odorant molecule by producing a ___ ___, thereby initiating the olfactory response
Only slight molecular alterations may distinguish different odorants

A

generator potential

108
Q

Concentration differences of the same substance can result in different odorants
Indole is a substance found in both coal tar and perfumes. Concentrated indole just plain stinks. When sufficiently diluted, indole gives off a fragrance like ___

A

Jasmine…

yep, that was the slide.

109
Q

___ are columnar epithelial cells of the mucous membrane lining the nose
They provide physical support, nourishment, and electrical insulation for the olfactory receptors

A

Supporting cells

chem slide 9 pic

110
Q

___ are interspersed among the supporting cells
They undergo continuous cell division producing new olfactory receptors, which live only about a month
Olfactory receptors are neurons, so their replacement is unusual since mature neurons are not generally replaced

A

Basal Stem cells

chem slide 10 pic

111
Q

Olfactory glands within the supporting connective tissue produce mucus
These ducted glands are also called ___ ___
The mucus moistens the olfactory epithelium surface, and dissolves odorants

A

Bowman’s glands

slide 11 pic

112
Q

Both supporting cells of the nasal epithelium and olfactory glands are innervated by branches of the ____ CN__?. Certain chemicals stimulate the nerve, causing tears and runny nose due to consequent action of the lacrimal glands and nasal mucous glands

A

Facial nerve (CN VII)

113
Q

The broad overall general mechanism whereby olfactory receptors react to odorant molecules is the same as most sensory reactors react to their specific stimuli

A

The stimulus (an odorant molecule) encounters the receptor

A generator potential develops and triggers one or more nerve impulses

114
Q

Olfaction has a low threshold (as do all the special senses)

Methyl mercaptan is added to natural gas because its threshold is extremely low, and because it is a recognizable, but not “usual” odor

A

Odor thresholds

115
Q

Adaptation to odors initially occurs rapidly—about 50% in the first few seconds after stimulation
After the first few seconds adaptation continues, but at a slower rate
Virtually complete insensitivity to some odors can occur in about a minute, even if the odors are strong

A

Adaptation to odors

116
Q

Bundles of slender, unmyelinated axons of olfactory receptors extend through olfactory foramina in the cribriform plate of the ethmoid bone

All the bundles taken together comprise the ___ nerve?

A

olfactory nerves (cranial nerve I)

117
Q

The olfactory nerves terminate in the ___ __ (paired masses of gray matter in the brain) within which the axon terminals of the first-order neurons (olfactory receptors) form synapses with dendrites and cell bodies of second-order neurons

A

olfactory bulbs

118
Q

Axons of olfactory bulb neurons extend posteriorly to form the ___ ___

The axons subsequently project into the lateral olfactory area, which is probably the primary olfactory area where conscious awareness of smells begins, as well as to other parts of the brain

A

olfactory tract

119
Q

Olfactory sensations are the only sensations that reach the cerebral cortex without first synapsing in the ____

A

thalamus

120
Q

Other axons of the olfactory tract project to the ___ ___ and hypothalamus, which accounts for emotional and memory-evoked responses to odors

A

Limbic system

121
Q

There are about 1,000 different kinds of receptor cells
Each receptor recognizes multiple odorants, and a single odorant can be recognized by multiple receptors
Different smells come from different combinations of receptors, so that 1,000 different types of sensors can identify 10,000 odors (similar to 26 letters of the alphabet being used in various combinations to form thousands of words)

A

many kinds of receptor cells

122
Q

Each different kind of receptor cell is scattered throughout the olfactory epithelium

The olfactory nerve for a given receptor type connects to just ## spots in the olfactory bulb

The second order neurons project from these spots on the olfactory bulb to the brain, forming a sensory map that is probably the same for each person (different mice are known to have the same sensory map)

A

Two

123
Q

New nerve cells formed from __ __ __ send out axons that find their way to the same spots in the olfactory bulb where their predecessors connected

Thus, roads on the odor map are constantly renewed so that destinations in the brain remain unchanged

A

basal stem cells

124
Q

reduced ability to smell

A

Hyposmia

125
Q

May be associated with age, since ability to smell decreases with age

May also be due to head injury, Alzheimer disease, Parkinson disease, smoking, and some drugs such as antihistamines, analgesics and steroids

A

Hyposmia

126
Q

total lack of sense of smell

A

anosmia

127
Q

Most result from…
Head injuries that tear the olfactory nerves, or from the
Aftereffects of nasal cavity inflammation (due to a cold, allergy, or smoking),
Physical obstruction of the nasal cavity (such as polyps)
Aging

A

Anosmia

128
Q

Zinc deficiency is the cause in many cases (one-third), so the cure is rapid once the correct form of zinc supplement is prescribed (zinc is a growth factor for the receptors of chemical senses)
Some (but not many) cases are due to genetic factors

A

Anosmia

129
Q

Receptors for taste sensations are located in the?

A

taste buds

130
Q

Most taste buds are on the ___, but some are also on the . . .
Soft palate (posterior portion of the roof of the mouth)
Pharynx (throat)
Epiglottis (cartilaginous flap over the voice box)

The number of taste buds declines with age

A

tongue

131
Q

Each taste bud is an oval body consisting of an aggregation of three kinds of neuroepithelial cells (a subtype of stem cell).
?

A

Gustatory receptor cells
Supporting cells (AKA sustentacular cells)
Basal cells

132
Q

At the apex of the taste bud is a small opening called the ______

Each gustatory receptor cell has a single, long microvillus, called a gustatory hair, which projects through the ____

A

Taste pore

133
Q

Basal cells produce supporting cells

Supporting cells then differentiate into ___ receptor cells

___ receptor cells have a life span of about ten days

A

Gustatory

134
Q

A ___ is a chemical that stimulates gustatory receptor cells

___ must be dissolved before they can be tasted (a substance that is not water-soluble can not be tasted)

After being dissolved (in saliva) the ___ contacts the plasma membrane of the gustatory hairs. The gustatory hairs are the sites of taste transduction

A

Tastant

135
Q

Physiology of gustation:

The gustatory hairs are the sites of taste ____

A

transduction

136
Q

The result of transduction is a receptor potential that stimulates ___ of synaptic vesicles from the gustatory receptor cell

The neurotransmitter molecules trigger nerve impulses in the first-order sensory neurons that synapse with the gustatory receptor cell

A

exocytosis

137
Q

Primary tastes are the fundamental tastes from which all other flavors of taste are composed

The five modern-day primary tastes are:

A 
Sweet
Sour 
Bitter
Salty
Umami
138
Q

Some also advocate adding fats to the list of primary tastes; others want to add calcium

There may be an ___ advantage conferred by each of the tastes

Receptors for taste are distributed over the tongue, but sensitivity for sweet, sour, bitter, and salty is acute at various positions on the tongue

A

Evolutionary

139
Q

Classic taste map of the tongue shown

A

slide 33

140
Q

____ tastes are associated with safe foods: we have an absolute requirement for carbohydrates

Acute sensitivity (conventional receptor location): tip of tongue

A

Sweet

141
Q

____ tastes are associated with spoiled foods: many foods become bitter or acidic when they spoil

Acute sensitivity (conventional receptor location): back sides of tongue

A

Sour

142
Q

___ tastes are associated with poisonous foods (many natural poisons and spoiled foods are bitter)

Acute sensitivity (conventional receptor location): back middle of tongue

A

Bitter

143
Q

___ tastes are associated with sodium chloride, something we need in our diet

Acute sensitivity (conventional receptor location): front sides of tongue (just back and to the side of sweet, perhaps somewhat overlapping sweet)

A

Salty

144
Q

___ is the taste of certain amino acids, which are the building blocks of protein

___ is a Japanese word for the taste imparted by glutamate in foods, and though there is no direct English translation it is often described as meaty, savory, or broth-like

Receptor location: diffuse (there is no conventional location)

A

Umami

145
Q

check out this guy on slide 36

A

MSG!

146
Q

Taste buds occur in elevations on the tongue called ___

A

Papillae

147
Q

There are three types of papillae that contain taste buds:

A 
Vallate Papillae
Fungiform papillae (mushroom-shaped)
Foliate papillae (mostly lost during childhood)
148
Q

___ papillae contain tactile receptors to discern the texture of food, but not taste buds

A

Filiform

149
Q

Each primary taste has a different threshold

The threshold for ____ substances is the lowest

The threshold for sour substances is somewhat higher than for ___ substances

The threshold for the remaining primary tastes are higher than for sour substances

A

bitter

150
Q

Complete adaptation to a specific taste can occur in #-# minutes (a relatively brief period of time) of continuous stimulation

A

1-5 minutes

151
Q

___ is the combination of taste (tongue) plus odor (olfactory epithelium).

A

Flavor

152
Q

Volatile food chemicals are carried into the nasal cavity from behind as we eat (____ ___).

Even though the same receptors in the olfactory epithelium act in ___ ___ and orthonasal olfaction (from the nostrils), the brain distinguishes between the two because it keeps track of breathing out and breathing in

A

retronasal olfaction

153
Q

The brain combines taste and __ __, creating flavor.

A

retronasal olfaction

154
Q

Taste receptor cells do not have an axon (the graded potentials they produce are called ___ ___, rather than generator potentials)

A

receptor potentials

155
Q

Gustatory receptor cells synapse with ___ of the first-order neurons that comprise the initial portion of the gustatory pathway

Each first-order neuron synapses with many gustatory receptor cells in several taste buds

A

dendrites

156
Q

Three cranial nerves include axons of first-order gustatory neurons from taste buds:

A

Facial nerve (cranial nerve VII), anterior two-thirds of the tongue

Glossopharyngeal nerve (cranial nerve IX), posterior one-third of the tongue

Vagus nerve (cranial nerve X), throat and epiglottis

157
Q

From the taste buds, impulses propagate along the appropriate cranial nerve to the gustatory nucleus in the ___ ___

A

medulla oblongata

158
Q

From the medulla some axons project to the limbic system and hypothalamus, others project to the thalamus and on to the primary gustatory area in the ___ __ of the cerebral cortex to give rise to the conscious perception of taste

A

parietal lobe

159
Q

The accessory structures of the eye are the . . .

A 
Eyelids 
Eyelashes 
Eyebrows 
Lacrimal (tearing) apparatus 
Extrinsic eye muscles
160
Q

The upper and lower eyelids . . .

Termed?

A

Palpebrae

161
Q 
Eyelids:
Shade the eyes during sleep 
Protect eyes from: 
\_\_
\_\_ 
Spread lubrication secretions over the eyes
A

Excessive light

Foreign objects

162
Q

The upper eyelid is more movable than the lower

The ___ ___ ___ muscle moves the upper eyelid

A

levator palpebrae superioris

163
Q

The ___ ___ is the space between the upper and lower eyelids

A

palpebral fissure

164
Q

The angles of the palpebral fissure are termed _____:

A

commissures

165
Q

The medial commissure is nearer the ___ bone

The lateral commissure is closer to the ___ bone

A

nasal

temporal

166
Q

The __ ___ is in the medial commissure, and contains
Sebaceous (oil) glands
Sudoriferous (sweat) glands

A

lacrimal caruncle

167
Q

Structures of the eyelid from superficial to deep: (7)

A 
Epidermis
Dermis
Subcutaneous tissue 
Fibers of orbicularis oculi muscle 
Tarsal plate 
Tarsal glands 
Conjunctiva
168
Q

The ___ __ is a thick fold of connective tissue that gives form and support to the eyelids

A

tarsal plate

169
Q

Tarsal glands (___ __) in each tarsal plate are modified sebaceous glands that secrete a fluid that helps keep the eyelids from adhering to each other

A

Meibomian glands

170
Q

The conjunctiva:
Thin, protective mucous membrane

Composed of ___ ___ __ with many goblet cells

A

stratified columnar epithelium

171
Q

___ conjunctiva lines inner aspect of the eyelids

A

Palpebral

172
Q

Bulbar conjunctiva is on the anterior surface of the eyeball

*covers sclera but not the ___

A

cornea

173
Q

The ___ ___ is a group of structures that produces and drains lacrimal fluid, or tears

A

lacrimal apparatus

174
Q

Lacrimal fluid is a watery solution containing salts, some mucus, and ___ (a bactericidal enzyme)

A

lysozome

175
Q

Lacrimal glands secrete lacrimal fluid
It then drains into the excretory lacrimal duct onto the surface of the ____ of the upper lid
The tears then pass medially over the eyeball

A

conjunctiva

176
Q

Tears next enter two small openings called ___ ___

A

lacrimal puncta

177
Q

Tears next enter two small openings called lacrimal puncta

Then the tears pass into two ducts called the ___ ___ (superior and inferior)

A

lacrimal canals

178
Q

The lacrimal canals lead to the lacrimal sac

Then to the ___ __

The __ ___ carries the lacrimal fluid into the nasal cavity

A

nasolacrimal duct

179
Q

Tears are normally carried away as fast as they are produced, either by evaporation or by passing into the lacrimal canals, then into the nasal cavity

___ is a protective mechanism: the tears dilute and wash away irritating substances

A buildup of tears can also occur when an inflammation of the nasal mucosa obstructs the nasolacrimal ducts

A

Lacrimation

A&P I (21 decks)

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