Chapter 18 - General and Special Senses Flashcards Preview

Anatomy Lecture > Chapter 18 - General and Special Senses > Flashcards

Flashcards in Chapter 18 - General and Special Senses Deck (133):
0

A specialized cell that sends sensations to CNS

Sensory receptor

1

Two major types of sensory receptors

- Tonic receptor
- Phasic receptor

2

Always sending signal to CNS

Tonic receptor

3

Becomes active only with changes in the conditions they monitor

Phasic receptor

4

Receptor that detect taste and smell

Chemoreceptor

5

Receptor that detects cell damage (mechanical, electrical, thermal)

Nociceptor

6

Receptor that detects thermal changes

Thermoreceptor

7

Receptor that detects hearing, stretching, and body position

Mechanoreceptor

8

Receptor that detects light

Photoreceptor

9

Area monitored by a single receptor

Receptor field

10

- Each receptor responds to a specific stimulus

Receptive field

11

Example of receptor specificity

Photoreceptor will not respond to a chemical stimulus

12

The sensory information arriving at the CNS

Sensation

13

Conscious awareness of sensation

Perception

14

How is perception the conscious awareness of sensation?

- All nerve impulses are identical (just action potentials)
- Brain interprets impulses
- "Feeling" that occurs when sensory impulses are interpreted

15

When does sensory adaptation occur?

Occurs when sensory receptors are subjected to continuous stimulation

16

What does sensory adaptation results in?

Reduction of sensitivity

17

For sensory adaptation, at some point along the pathway, impulses are _____

Conducted at a decreased rate

18

When sensory receptors decrease their level of activity

Peripheral adaptation

19

- Sensory neurons are still active
- CNS causes reduced perception

Central adaptations

20

What are the sensory limitations?

- Sensory information from receptors is incomplete

21

How is sensory receptors incomplete?

- Do not have receptors for every stimulus (animals detecting infrared, uv, ultrasonic)
- Receptors have limited ranges
- Stimulation requires a neural event that is interpreted

22

Do not have specialized receptor cells or sensory organs

General senses

23

What are special senses?

- Can have specialized receptor cells separate from the sensory neuron
- Structurally more complex
- Receptors localized in sense organs

24

Three major groups of general sense with their meanings

Exteroceptors - relay info about external environment
Proprioceptors - depict body position in space
Interoceptors - monitor the internal environment

25

What are nociceptors?

- Sense tissue damage
- Perceived as pain
- Free nerve endings with large receptive field

26

Where are nociceptors found?

Found everywhere except brain

27

What function do nociceptors have?

- Provide a protective function
- Do not adapt well

28

Quick, inducing a reflex usually, end when stimulus ends (prickling)

Fast pain

29

Begin later; persist longer, ache (burning)

Slow pain

30

What is referred pain

- "brain-freeze"
- visceral pain that feels like it is coming from a more superficial region
- Due to superficial structure being innervated by the spinal nerves as the damaged viscera

31

What are thermoreceptors?

- Involve heat and cold (no differences in structure between the two)
- Free nerve endings in skin
- Quick to adapt
- Felt as pain if temp goes above 45C or below 10C

32

Sensitive to mechanical forces that cause tissues to be deformed

Mechanoreceptors

33

Types of mechanoreceptors with their meanings

Tactile - touch, pressure, vibration
Baroreceptors - pressure changes in walls of vessels
Proprioceptors - position of joints and muscles

34

Two types of tactile receptors

- Unencapsulated
- Encapsulated

35

Three different types of unencapsulated tactile receptors

Free nerve endings
Root hair
Tactile disc

36

- In papillary dermis
- General touch

Free nerve endings

37

Monitor distortions and movement across body surface

Root hair

38

Expanded nerve terminal that synapses with Merkel cell
- Sensitive to fine touch

Tactile disc

39

Three types of encapsulated cells

- Tactile (Meissner's) corpuscles
- Lamellated (Pacinian) corpuscle
- Ruffini Corpuscle

40

Found where tactile sensitivities are very well developed

Tactile corpuscles

41

Respond to deep pressure

Lamellated corpuscle

42

- In dermis
- Detect pressure with little adaptation

Ruffini corpuscle

43

What are baroreceptors?

- Stretch receptors
- Monitor changes in pressure (detect stretching of tissue walls)

44

What do baroreceptors regulate?

Autonomic activities
- Digestive tract
- Bladder
- Carotid sinus
- Lung
- Colon
- Major arteries

45

What do proprioceptors do?

- Monitor position of joints, tension in tendons, state of muscle contraction
- No adaptation to stimulus

46

Types of proprioceptors with meanings

Muscle spindle - monitor length of muscle
Golgi tendon organ - monitor tension in a tendonduring contraction (degree in which tendon is stretched)

47

What are chemoreceptors?

- Respond to substances dissolved in surrounding fluids
- Monitor chemical composition of body fluids

48

Examples of chemoreceptors monitoring chemical composition of body fluids

Sensitive to pH, pCO2 changes

49

Where are chemoreceptors found?

- Inside CNS; medulla
- Aortic bodies
- Carotid bodies

50

Sense of smell

Olfaction

51

Where is the olfactory organ and what composes it?

- Located within the nasal cavity on either side of nasal septum
- Covers the CRIBRIFORM PLATE of ethmoid
- Made up of OLFACTORY EPITHELIUM

52

Olfactory epithelium consists of what?

Olfactory receptors - chemoreceptors
Supporting cells - surround the receptors
Basal cells - stem cells that grow new cells
- Covered in secretions from OLFACTORY GLANDS

53

What are olfactory receptors?

- Highly modified bipolar neurons
- Have cilia that extend into mucus secreted by olfactory glands
- Odorous particles dissolve into mucus and cause depolarization

54

Olfactory nerve pathway

- Impulses travel along AXONS of RECEPTOR CELLS
- pass through openings in the CRIBRIFORM PLATE
- Go to OLFACTORY BULB and CRANIAL NERVE 1
- Unique in that the impulses DO NOT go to the THALAMUS
- Travel along TRACTS to the LIMBIC SYSTEM
- Smells can trigger strong EMOTION
- Interpreted as SMELL in TEMPORAL LOBE and BASE OF FRONTAL

55

What is olfactory discrimination?

- No structural difference in receptor cells
- Olfactory can turn-over (reproduce) (numbers decrease with age)
- 50 primary smells (can distinguish thousands of smells)
- Adapt quickly

56

Taste = ?

Gustation

57

Chemoreceptors in structure called _____
- Gustation

Taste buds

58

Taste buds on superior surface of tongue in ____

Papillae

59

What are papillae?

- Epithelial projections
- Taste buds lie along papillae

60

Three types of papillae?

- Filiform
- Fungiform
- Circumvallate

61

- In taste buds
- Receptor clusters
- About 40 per bud

Gustatory cell

62

Replace receptors every 10-12 days in taste buds

Basal cells

63

Gustatory cells extend microvilli called a ____ in a ____

Taste hair into a taste pore

64

Gustatory Pathway

- Uses cranial nerve VII, IX, and X
- Afferent fibers synapse with NUCLEUS SOLITARIUS in medulla
- Goes to thalamus and cerebral cortex

65

Primary tastes

- Sour
- Sweet
- Salt
- Bitter
- Water
- Umami

66

what is Gustatory discrimination?

- Individual differences in taste
- Number and sensitivity decrease with age

67

Parts of the external ear

- Auricle
- External acoustic meatus
- Tympanic membrane

68

External structure supported elastic cartilage

Auricle

69

Canal to middle ear

External acoustic meatus

70

Makes wax (cerumen)

Ceruminous glands

71

What does the external acoustic meatus have?

- Hair
- Ceruminous glands

72

The external acoustic meatus ends where?

Tympanic membrane

73

Functions of the external ear?

- Protects middle and inner ear
- Limits microoganism growth
- Deny access to foreign objects
- Funnel vibrations

74

Components of the middle ear

- Tympanic cavity
- Tympanic membrane
- Auditory tube
- Ossicles
- Muscles

75

Air filled space between external and inner ear

Tympanic cavity

76

Thin, transparent connective tissue sheet

Tympanic membrane

77

When teh auditory tube is open.....

- Middle ear equalized to atm pressure
- Can be induced by chewing or yawning
- Allows for microbes to get in and cause and ear infection

78

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

Ossicles

79

Three ossicles

- Malleus
- Incus
- Stapes

80

Two types of muscles with their meanings

Tensor tympani muscle - inserts on malleus
Stapedius muscle - inserts on stapes

81

A series of tubes and cavities in the ear

Inner ear

82

Two section so the inner ear

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

83

Inner ear consists of several layers

1. Membranous labyrinth
2. Bony (osseous) labyrinth

84

What does the membranous labryinth contain?

Endolymph fluid

85

What does the bony labyrinth contain?

- Dense bone layer of temporal
- Contains perilymph fluid

86

What does the cochlea do?

- Converts vibrations to sound
- Contacts the stapes at the oval window
- Coiled tube with cochlear duct

87

The cochlea is divided into three ducts

1. Vestibular duct - divided by the vestibular membrane
2. Cochlear duct - divided by the basilar membrane
3. Tympanic duct

88

Where is the organ of corti found?

On the basilar membrane

89

What is in the organ of corti with their meanings?

Hair cells - mechanoreceptors with stereocillia
Cranial nerve VIII - Cochlear branch contact hair cells
Tectorial membrane - positioned right above hair cell stereocilia

90

Path of Vibrations

1. Auricle funnels vibrations into meatus
2. Tympanic membrane vibrates
3. Transmits to ossicles (malleus to incus to stapes)
4. Stapes connected to oval window (transmits vibrations to inner ear)
5. Oval window vibrates; perilymph moves
6. Membranous labyrinth vibrates (cochlear duct vibrates within)
7. Basilar membrane bounces (hair cell stereocilia contact tectorial membrane, become deformed and creates depolarization, transmits an action potential down CN VIII)

91

Pathway for auditory sensations

- Carried by cochlear branch of cranial nerve VIII
- Goes to cochlear nucleus of medulla
- Travel through thalamus
- Processed in AUDITORY CORTEX of temporal lobe

92

Vestibule consists of two parts

Semicircular canals
Utricle and saccule

93

- Three (anterior, lateral, and posterior)
- Surrounding semicircular ducts

Semicircular canals

94

At the base of semicircular canals

Ampulla at base

95

Each ampulla possess a _____ that attaches to a _____

Cristae, cupula

96

- Paired membranous sacs
- Conected by endolymphatic duct

Utricle and saccule

97

Saccule possess ___

Maculae

98

The cupula has ___

Hair cells

99

How does head rotation work?

- Causes fluid to move through canals
- Fluid moves cupula
- Hair cells stereocilia bends
- Depolarization occurs

100

The maculae consists of what?

- Hair cells
- Otolith

101

Small calcium carbonate crystals
- Gel like substance

Otolith

102

As head orientation changes

- Gravity pulls on crystals
- Moves otolith
- Deforms hair cell stereocillia
- Depolarization occurs

103

Pathway for balance sensation

Hair cells
- Activate neurons of vestibular branch of cranial nerve VIII
- Synapses with vestibular nuclei

104

Eye accessory structures

Eyelids or palpebrae
Tarsal glands
Conjunctiva

105

Function and location of palpebrae

- Protects and lubricates
- Epidermis, dermis, and CT

106

Function of tarsal glands

Oily secretions keep lids from sticking together

107

Thin protective mucus membrane on the eye

Conjunctiva

108

Two parts to the conjunctiva

Palpebral and bulbar

109

Where does the conjuntiva stop?

At the corneal edge

110

How are conjunctiva bloodshot?

Dilated blood vessels

111

- Produces tears

Lacrimal apparatus

112

Lacrimal apparatus consists of what?

Lacrimal glands - produce tears
Lacrimal punctum - drains tear into....
Lacrimal canaliculi - passageway that leads to the ....
Lacrimal sac - fills groove on lacrimal bone and connects to the ...
Nasolacrimal duct - delivers tears to nasal cavity

113

Three layers of the eye

Fibrous tunic
Vascular tunic
Neural tunic

114

- Outer tunic

Fibrous tunic

115

Part of the fibrous tunic

Sclera - white of eye, dense irregular CT
Cornea - transparent layer

116

Parts of the vascular tunic

Iris - smooth muscles and pigments, controls the size of the pupil
Choroid - vascularized, pigmented layer
Lens - layered proteins, refracts light
Ciliary body

117

- Below the iris
- Has ciliary process
- Ciliary muscles change the lens shape (focus)

Ciliary body

118

- Attach to suspensory ligaments
- Attach to lens

Cilary processes

119

Functions of the vascular tunic

- Route for BVs
- Regulate amounts of light
- Secrete and absorb aqueous humor
- Control shape of lens

120

- Inner most layer
- Consists of Retina
- 5 groups of retinal neruons

Neural Tunic

121

Retinal neruons

Receptor cells
Bipolar neurons
Ganglion cells
Amacrine cells

122

Contains rods and cones
- Detect light

Receptor cells

123

Synapse with receptor cells

Bipolar neurons

124

Synape with biopolar neurons

Ganglion cells

125

Modulate communication between bipolar and ganglion cells

Amacrine cells

126

- Very light sensitive
- Do not discriminate color
- Requires less light

Rods

127

- Color vision
- Three types
- Give sharper images

Cones

128

Regions of the retina with meanings

Macula lutea - area of no rods
Fovea centralis - area of most cones (within macula)
Optic disc - beginning of optic nerve, "blind spot'

129

Visual pathway.....

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

130

Two cavities in the eye

1. Posterior cavity - contains gelatinous vitreous body
2. Anterior cavity - contains clear aqueous humor

131

Patrick's new watch looks very _______

nice

132

this species is 6"1', 180 lbs., resides in its natural habitat of New York and commonly has blue eyes and curly hair

what is a Patrick Carbary