Chapter 18 - General & Special Senses Flashcards Preview

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Flashcards in Chapter 18 - General & Special Senses Deck (152):
1

What are sensory receptors?

A specialized cell that sends sensations to CNS.

2

What are the types of sensory receptors?

Tonic and phasic.

3

What doe tonic receptors do?

Always sending signals to CNS.

4

What do phasic receptors do?

Becomes active only with changes in the conditions they monitor.

5

What are the types of receptors?

Chemoreceptors, nociceptors, thermoreceptors, mechanoreceptors, photoreceptors.

6

What is the function of chemoreceptors?

Taste and smell.

7

What is the function of nociceptors?

Cell damage (mechanical, electrical, thermal,).

8

What is the function of thermoreceptors?

Thermal.

9

What is the function of mechanorecepors?

Hearing, stretching, and body position.

10

What is the function of photoreceptors?

Light.

11

Receptor characteristics?

Receptive field and receptor specificity.

12

What are receptive fields?

Area monitored by a single receptor cell.

13

What is receptor specificity?

Each receptor responds to a specific stimulus (photoreceptor will not respond to a chemical stimulus).

14

What is sensation?

The sensory information arriving at the CNS.

15

What is perception?

Conscious awareness of sensation.

16

Perception characteristics?

All nerve impulses are identical, brain interprets impulses, and feeling that occurs when sensory impulses are interpreted.

17

Sensory adaptation characteristics?

Occurs when sensory receptors are subjected to continuous stimulation, results in a reduction of sensitivity, at some point along the pathway impulses are conducted at a decreased rate, there are several types.

18

What are the types of sensory adaptations?

Peripheral adaptation and central adaptation.

19

What is peripheral adaptation?

When sensory receptors decrease their level of activity.

20

What is central adaptation?

Sensory neurons are still active and CNS causes reduced perception.

21

What are sensory limitations?

Information from receptors is incomplete, do not have receptors for every stimulus, receptors have limited range, and stimulation requires a neural event that is interpreted.

22

What are some animals can detect that humans cannot?

Infrared, ultraviolet, ultrasonic, and magnetism.

23

What are general senses?

Do not have specialized receptor cells or sensory organs.

24

What are special senses?

Can have specialized receptor cells separate from the sensory neuron, structurally more complex, and receptors are localized in sense organs.

25

What are the major groups of general senses?

Exteroceptors, proprioceptors, and interoceptors.

26

What are exteroceptors?

Relay info about external environment.

27

What are proprioceptors?

Depict body position in space.

28

What are interoceptors?

Monitor the internal environment.

29

What are nociceptors?

Sense tissue damage, perceived as pain, and free nerve endings with large receptive field.

30

Nociceptor characteristics?

Found everywhere except brain, provide a protective function, and do not adapt well.

31

What are the types of pain?

Fast pain (prickling), slow pain (burning), and referred pain.

32

What is fast pain?

Quick, inducing a reflex usually end when stimulus ends.

33

What is slow pain?

Begin later, persist longer, ache.

34

What is referred pain?

Visceral pain that feels like it is coming from a more superficial region.

35

What causes referred pain?

Superficial structures being innervated by the same spinal nerves as the damaged viscera.

36

Example of referred pain?

Brain freeze.

37

Thermoreceptor characteristics?

Involve heat & cold, free nerve endings in skin, quick to adapt, and felt as pain.

38

When do thermoreceptors feel pain?

If temp goes above 45 C or if temp goes below 10 C.

39

Mechanoreceptor characteristics?

Sensitive to mechanical forces that cause tissues to be deformed.

40

Types of mechanoreceptors?

Tactile, baroreceptors, and proprioceptors.

41

What do tactile receptors sense?

Touch, pressure, and vibration.

42

What do baroreceotors detect?

Pressure changes in walls of vessels, etc.

43

What do proprioceptors sense?

Position of joints & muscles.

44

How many types of tactile receptors are there?

6.

45

How many categories of tactile receptors are there?

2.

46

What are the categories of tactile receptors?

Unencapsulated and encapsulated.

47

What are the unencapsulated tactile receptors?

Free nerve endings, root hair, and tactile disc.

48

Where are free nerve endings and what do they detect?

In papillary of dermis. General touch.

49

What do root hair receptors detect?

Monitor distortions & movement across body surfaces.

50

Where are tactile discs and what do they detect?

Expanded nerve terminal that synapses with merkel cell. Sensitive to fine touch.

51

What are the encapsulated tactile receptors?

Tactile (meissner's) corpuscles, lamellated (pacinian) corpuscles, and ruffini corpuscles.

52

Where are tactile corpuscles found?

Where tactile sensitivities are very well developed.

53

What do lamellated corpuscles respond to?

Deep pressure.

54

Where are ruffini corpuscles and what do they detect?

In the dermis. Detect pressure with little adaption.

55

What is another name for baroreceptors?

Stretch receptors.

56

What do baroreceptors regulate?

Autonomic activities such as... Digestive tract, bladder, carotid sinus, lung, colon, and major arteries.

57

What are the types of proprioceptors.

Muscle spindles and golgi tendon organ.

58

What do muscle spindle proprioceptors detect?

length of muscle.

59

What do golgi tendon organ proprioceptors detect?

tension in a tendon during contraction.

60

what do chemoreceptors respond to?

Substances dissolved in surrounding fluids

61

What do chemoreceptors do?

Monitor chemical composition of body fluids (pH, PCO2 changes).

62

Where are chemoreceptors found?

Inside CNS (medulla), aortic bodies, and carotid bodies.

63

What are general senses?

Do not have specialized receptor cells or sensory organs.

64

What are special senses?

Can have specialized receptor cells separate neuron, structurally more complex, and receptors localized in sense organs.

65

What is olfaction?

sense of smell.

66

Olfactory organ characteristics?

Locatd within the nasal cavity on either side of nasal septum, covers the cribiform plate of ethmoid, and made up of olfactory epithelium.

67

What does olfactory epithelium consist of?

Olfactory receptors, supporting cells, and basal cells.

68

What type of receptor are olfactory receptors?

Chemoreceptors.

69

What are supporting cells?

Surround the receptor.

70

What are basal cells?

Stem cells that crow new cells.

71

What is olfactory epithelium covered in?

Secretions from olfactory glands.

72

Olfactory receptor characteristics?

Highly modified bipolar neurons, have cilia that extend into mucus secreted by olfactory glands, and odorous particles dissolve into mucus and cause depolarization.

73

Olfactory nerve pathway?

1. Impulses travel along axons of receptor cells.
2. Pass through openings in cribiform plate.
3. Go to olfactory bulb and cranial nerver I.
4. Travel along tracts to limbic system.
5. interpreted as smell in temporal lobe & base of frontal.

74

How is the olfactory nerve pathway unique?

The impulse does not go through the thalamus.

75

Smells can?

Trigger strong emotion.

76

What is olfactory discrimination?

Olfactory can turn over (decrease with age), adapt quickly, and no structural difference in receptor cells.

77

How many primary smells are there?

50.

78

What is gustation?

taste.

79

What are chemoreceptors of gustation called?

Taste buds.

80

Where are taste buds located?

On superior surface of tongue in papillae.

81

What is the papillae?

Epithelial projections and taste buds run along papillae.

82

What are the types of papillae?

Filiform, fungiform, and circumvallate.

83

How many gustatory cells (receptor) clusters are on a taste bud?

40 per.

84

How often do basal cells replace receptors?

10 - 12 days.

85

What are taste hairs made of?

Microvilli extended by gustatory cells into taste pore.

86

What is the gustatory pathway?

1. Use cranial nerves VII, IX, and X.
2. Afferent fibers synapse with nucleus solitarius in medulla.
3. Goes to thalamus & cerebral cortex.

87

What are the primary tastes?

Sour, sweet, salt, bitter, water, umami.

88

Number and sensitivity to taste (increases or decreases) with age?

Decrease

89

External structure supported by elastic cartilage

Auricle

90

Canal to the middle of ear

External Acoustic Meatus

91

Type of gland that makes wax

Ceruminous Glands

92

Functions of the External Ear (4)

1. Protect middle and inner ear
2. Limits microorganism growth
3. Deny access to foreign objects
4. Funnel vibrations

93

Structure that when opened, middle ear equalized to atmospheric pressure
-This can be induced by chewing or yawning
-Allows for microbes to get in and cause ear infection

Auditory Tube

94

-Tiny bones in middle ear
-Transfer vibrations from the tympanic membrane to the inner ear

Ossicles

95

3 ossicles

1. Malleus
2. Incus
3. Stapes

96

2 Muscles of the Inner Ear

1. Tensor Tympani Muscle
2. Stapedius Muscle

97

Where does the tensor tympani muscle insert?

Malleus

98

Where does the stapedius muscle insert?

Stapes

99

The inner ear is split up into 2 sections...

1. Vestibule (balance)
2. Cochlea (hearing)

100

The 2 layers of the inner ear...

1. Membranous labyrinth
2. Bony Labyrinth

101

What does the membranous labyrinth contain?

Endolymph fluid

102

What does the bony labyrinth contain?

Perilymph fluid

103

Structure that converts vibrations to sound
-Contacts the stapes at the oval window

Cochlea

104

The cochlea is divided into what 3 ducts?

1. Vestibular duct
2. Cochlear Duct
3. Tympanic duct

105

Where is the organ of corti found?

Basilar membrane

106

What does the organ of corti contain? (3)

1. Hair cells
2. Cranial Nerve 8
3. Tectorial membrane

107

Mechanoreceptors with stereocillia

Hair cells

108

Cochlear branch contacts hair cells at...

Cranial Nerve 8

109

This structure is positioned right above hair cell stereocilia

Tectorial Membrane

110

Pathway of vibrations... (6)

1. Auricle funnels vibrations into meatus
2. Tympanic membrane vibrates
3. Transmits to ossicles (malleus, incus then stapes)
4. Stapes connected to oval window, that transmits vibrations to inner ear, oval window vibrates, perilymph moves
5. Membranous labyrinth vibrates (cochlear duct vibrates within)
6. Basilar membrane bounces (hair cell stereocilia contact tectorial membrane, transmits action potential to CN 8)

111

Pathway of Auditory Sensations (4)

1. Carried by cochlear branch of Cranial Nerve 8
2. Goes to cochlear nucleus of medulla
3. Travels through thalamus
4. Processed in auditory cortex of temporal lobe

112

What 3 structures does the vestibule contain?

1. Semicircular canals
2. Utricle
3. Saccule

113

At base of the semicircular canals

Ampulla- each possesses cristae that attaches to the cupula

114

-Paired membranous sacs
-Connected by endolymphatic duct

Urticle and Saccule

115

What does the saccule possess?

Maculae

116

What happens during head rotation?

1. Causes fluid to move through canals
2. Fluid moves through the cupula
3. Hair cell stereocilia bends
4. Depolarization occurs

117

What does the maculae consist of? (2)

1. Hair cells
2. Otolith

118

-Small calcium carbonate crystals
-Gel like substances

Otolith

119

What happens when head orientation changes? (4)

1. Gravity pulls on crystals
2. Moves otolith
3. Deforms hair cell stereocilia
4. Depolarization occurs

120

Structure that activates neurons of vestibular branch of cranial nerve 8
-Synapses with vestibular nuclei

Hair cells

121

-Structure that protects and lubricates
-Epidermis, dermis, CT

Eyelids or Palpebrae

122

Gland that is responsible for oily secretions that keep lids from sticking together

Tarsal Glands

123

Thin protective mucus membrane
-Palpebral and bulbar
-Stops at corneal edge
-Dilated BV= bloodshot

Conjunctiva

124

Gland that produces tears?

Lacrimal Gland

125

Where tears drain into

Lacrimal Punctum

126

Passageway that leads to the lacrimal sac

Lacrimal Canaliculi

127

Structure that fills the groove on the lacrimal bone

Lacrimal Sac

128

Delivers tears to the nasal cavity

Nasolacrimal Duct

129

The 3 layers of the eye

1. Fibrous tunic
2. Vascular Tunic
3. Neutral Tunic

130

-White of eye
-Dense irregular connective tissue

Sclera

131

Transparent layer

Cornea

132

-Smooth muscle and pigments
-Controls the size of the pupils

Iris

133

Vascularized pigment layer

Choroid

134

Layered proteins
-Refracts light

Lens

135

-Structure in the vascular tunic
-Below the iris
-Has ciiliary processes
-Attach to suspensory ligaments

Ciliary Body

136

Ciliary muscles change the lens shape with changes the...

Focus

137

Functions of the vascular tunic (4)

1. Route of BV's
2. Regulate amount of light
3. Secrete and absorb aqueous humor
4. Control shape of lens

138

5 Retinal Neurons Groups (only 4 listed)

1. Receptor cells
2. Bipolar neurons
3. Ganglion cells
4. Amacrine cells

139

Retinal neuron that... detects light, rods and cones

Receptor cells

140

Retinal Neuron that... synapse with receptor cells

Bipolar cells

141

Retinal Neuron that... synapses with bipolar neurons

Ganglion cells

142

Retinal Neuron that... modulate communication between bipolar and ganglion cells

Amacrine cells

143

Very light sensitive, do not discriminate color, requires less light

Rods

144

Color vision, 3 types, give sharper image

Cones

145

Regions of the Retina

1. Macula Lutea
2. Fovea Centralis
3. Optic Disc

146

Area of no rods

Macula Lutea

147

Area of most cones, within macula

Fovea Centralis

148

Beginning of the optic nerve , blind spot

Optic Disc

149

The steps of the visual pathway

1. Photoreceptors to...
2. Bipolar cells to...
3. Ganglion axons converge on optic disc into optic nerve (Cranial nerve 2)
4. Optic tract to optic chiasm
5. Relayed to lateral geniculate nucleus
6. Onto visual cortex of occipital lobe

150

Cavities of the eye? (2)

1. Posterior cavity
2. Anterior Cavity

151

What does the posterior cavity contain?

Vitreous Body

152

What does the anterior cavity contain?

Aqueous humor