Special Senses Flashcards Preview

Z Old Anatomy > Special Senses > Flashcards

Flashcards in Special Senses Deck (111):
1

2

Sensory Receptors

- peripheral (distal) endings of sensory neurons

- specific for certain types of stimuli (ex: photoreceptors for light)

- depolarize neurons to produce action potential

3

Modality-based Receptor Classification

  1. Chemo-
  2. Thermo-
  3. Mechano-
  4. Photo-
  5. Noci-
  6. Baroreceptors

4

Stimulus Origin-based Receptor Classification

  1. interoreceptors - detect internal stimuli
  2. proprioceptors - body position/movement
  3. exteroceptors - detect external stimuli

5

Distribution-based Receptor Classification

General Senses - widely distributed

Special Senses - limited to head

6

General Senses

  • temperature
  • pain
  • touch pressure
  • vibration
  • proprioception

7

Special Senses

  • smell
  • taste
  • vision
  • equilibrium
  • hearing

8

What makes a sense "special"?

- localized (confined to head)

- special receptor cells

- housed in complex sensory organs or epithelial structures

- cranial nerves carry special sensory info to brain

9

Chemical Senses

 - Chemoreceptors that respond to chemicals binding to them

- Taste - gustation

- Smell - olfaction

10

Q image thumb

Taste Bud

- 50-100 epithelial cells in a bundle containing long microvilli that receive chemicals from food that create flavors

11

surface elevations of tongue

Q image thumb

Tongue Papillae

- contain taste buds

12

light blue lateral cells

Q image thumb

supporting cell of taste bud

13

central purple cells

Q image thumb

gustatory cell

- taste receptor cells

- have long microvilli known as gustatory hairs that extend through taste pores

14

Gustatory Pathway

  1. taste info travels primarily via Facial (VII) and Glossopharyngeal (IX) nerves (some via Vagus (X)) 
  2. primary sensory neurons synapse in solitary nucleus of medulla
  3. secondary neurons synapse in thalamus
  4. tertiary neurons synapse in gustatory cortex of cerebrum

15

olfactory epithelium

Q image thumb

- specialized nasal cavity epithelium containing olfactory receptor cells

16

purple structure

Q image thumb

olfactory neuron

- specialized chemoreceptive cell in olfactory epithelium

- bipolar, basal side has axon, apical side has cilia

- axons gather into bundles that make up olfactory nerve, pass through ethmoid (olfactory foramina of cribriform plate), attach to olfactory bulbs of forebrain

17

pink structure

Q image thumb

supporting cells

- columnar cells that support olfactory neurons

18

small green inferior structure

Q image thumb

Basal Cell

- form new olfactory neurons 

19

orange structure towards bottom

Q image thumb

basal cell

- replace gustatory cells

20

large yellow structure

Q image thumb

olfactory bulb

- structure on inferor side of frontal lobes that sits above cribriform plate of ethmoid bone and connects with olfactory nerve filaments

21

Olfaction Pathway

  1. Olfactory Bulb
  2. Olfactory Tract
  3. then to 3 areas of brain:
  • Limbic Region (associate smell w/ emotion)
  • Piriform Lobe of Cortex (conscious perception)
  • Thalamus and Orbitofrontal Cortex (analysis and comparison of smell)

22

Q image thumb

olfactory tract

23

not the muscle, but the structure it moves

Q image thumb

Palpebrae

- AKA eyelids

- one upper, one lower per eye

24

Q image thumb

Medial and Lateral Canthi (singular: canthus)

- AKA medial/lateral angles

25

Q image thumb

levator palpebrae superioris

- muscle that opens eyelid

26

thin layer on anterior whites of eyes and inside eyelids

Q image thumb

conjunctiva

- straitified squamous epithelium that produces lubricating mucus

- in eyelids, called Palpebral conjunctiva

27

number 1

Q image thumb

Lacrimal gland

- produces tears

- contains lysozyme, a bactericidal enzyme

28

Q image thumb

lacrimal puncta

- tiny openings for lacrimal fluid to drain into

29

number 5

Q image thumb

lacrimal caruncle

- small, pink, globular nodule at the inner corner of eye

- contains sebaceous and sudoriferous glands

- source of "eye boogers"

30

# 6

Q image thumb

superior oblique muscle

- depresses eye, turns it laterally

31

# 8

Q image thumb

inferior oblique muscles

- elevates eye, turns it laterally

32

#2

Q image thumb

superior rectus muscle

- elevates eye, turns it medially

33

#3

Q image thumb

inferior rectus muscle

- depresses eye, turns it medially

34

#4

Q image thumb

medial rectus muscle

- moves eye medially

35

#5

Q image thumb

lateral rectus muscle

- moves eye laterally

36

Lacrimal Apparatus

system for keeping eye's surface moist

- three parts:

  • lacrimal gland
  • lacrimal sac
  • lacrimal fluid

 

37

Q image thumb

lacrimal sac

area just medial to eye where lacrimal fluid gathers and empties into nasal cavity

38

lacrimal fluid

- made up of mucus, antibodies and lysozyme

39

#7

Q image thumb

Trochlea

- point where superior oblique muscle is anchored above eye

40

Three Tunics of the Eye

Fibrous - sclera and cornea

Vascular - choroid, ciliary body, iris

Sensory - retina

41

Fibrous Tunic

- most external layer

- two regions:

  1. Sclera
  2. Cornea

42

Vascular Tunic

3 parts:

  1. Choroid
  2. Ciliary Body
  3. Iris

43

Sensory Tunic

- AKA Retina

two layers:

  1. pigmented layer
  2. neural layer

44

#1

Q image thumb

Sclera

- poster 5/6s of fibrous tunic

- white, opaque

- gives eye shape, anchors eye muscles

45

#8

Q image thumb

Cornea

- anterior 1/6 of fibrous tunic

- transparent, coveres iris and pupil

- avascular, innervated

46

#5

Q image thumb

scleral venous sinus

AKA Schlemm's Canal

- large blood vessel near junction of sclera and cornea

- drains aqueous humor

 

47

part of eye furthest forward

anterior pole

48

part of eye furthest back

posterior pole

49

#28

Q image thumb

Choroid

- vascular, darkly pigmented membrane of vascular tunic

- prevents light from scattering within eye

- middle layer between sclera and retina

50

structure composed of #3 and #12

Q image thumb

ciliary body

- thickened ring of smooth muscle tissue encircling lens

- made of ciliary muscles and processes

51

#3

Q image thumb

ciliary muscle

muscles of ciliary body that alter lens shape

52

#12 (folds covering ciliary muscle)

Q image thumb

Ciliary Processes

- folds of epithelium

- secrete aqueous humor

53

#4

Q image thumb

suspensory ligaments

AKA ciliary zonule

- extend from ciliary body to lens, allowing ciliary muscle to move lens

54

#7

Q image thumb

Iris

- contractile smooth muscle structure:

  • Circular sphincter muscle
  • Radial dilator muscle

- colored part of eye

- attached to ciliary body

- regulates amount of light entering eye

55

#8

Q image thumb

pupil

- opening in iris through which light enters

- controlled by iris

56

#30

Q image thumb

retina

- layer lining back of interior of eye

- contains photoreceptors

- contains two layers:

  • pigmented layer - melanocytes
  • neural layer - rods, cones, bipolar cells, ganglion cells

 

57

jagged portion here where choroid meets ciliary body

Q image thumb

ora serrata

- posterior margin of ciliary body, where neural layer meets front of eye

58

#25

Q image thumb

macula lutea

- yellowish region of retina

- small pit at center of posterior pole

- area of maximum visual acuity

59

#26

Q image thumb

fovea centralis

- the center of the macula

- contains only cone cells

- region of highest visual acuity

60

#18

Q image thumb

optic disc

AKA blind spot

- lacks neurons

- where optic nerve exits eye

61

#10 and #11

Q image thumb

Lens

- transparent body behind iris and pupil, in front of vitreous humor

- focuses light onto retina

- made up of lens fibers produced by lens epithelium

62

basic component of the lens

lens fiber

- cells without organelles, only cytoplasm

- made by lens epithelium, continuously added

63

lens epithelium

- cuboidal cells covering anterior of lens

- create lens fibers

64

internal chambers and fluids of eye

  1. Anterior Segment - two chambers, aqueous humor
  2. Posterior Segment - vitreous humor

- divided by suspensory ligaments and lens

65

anterior segment

- two chambers:

  • Anterior Chamber - btwn cornea and iris
  • Posterior Chamber - btwn iris and lens

- filled with aqueous humor:

  • renewed continuously
  • formed as blood filtrate
  • nourishes lens and cornea

66

posterior segment

- inside of eye behind the lens

- filled with vitreous humor:

  • clear, jelly-like
  • transmists light
  • supports posterior of lens
  • maintains intraocular pressure

67

#22

Q image thumb

optic nerve

- cranial nerve II

- carries signals from eye to optic chiasm

68

#1

Q image thumb

pigmented layer of retina

- layer of melanocytes between retinal neurons and choroid

69

#2-9

Q image thumb

Neural Layer of Retina

- contains 3 types of cells:

  • photoreceptors
  • bipolar cells
  • ganglion cells

 

70

entire structure

Q image thumb

rod cell

- more sensitive to light

- allows vision in dim light

71

entire structure

Q image thumb

cone cell

- operate best in bright light

- allows high-acuity color vision

72

structure shown in red

Q image thumb

bipolar cells

- bipolar neurons which transmit signals from photoreceptor cells to ganglion cells

73

leftmost, darker structures

Q image thumb

Ganglion Cells

- outermost neurons of retina whose axons exit at optic nerve to carry visual stimuli to brain

74

three main regions of ear

outer ear - hearing

middle ear - hearing 

inner ear - hearing and equilibrium

 

75

- specialized apocrine sweat glands that secrete earwax

ceruminous glands

76

visible outer ear

Q image thumb

Pinna

- AKA auricle

- collects sound, directs it to outer ear canal

77

indicated by black line

Q image thumb

external auditory canal (or acoustic meatus)

- tube through which sound travels to eardrum

78

Q image thumb

tympanic membrane

AKA eardrum

- vibrates when soundwave hits it

- separates outer and middle ear

79

external ear

made up of:

pinna

external auditory canal

tympanic membrane

80

Q image thumb

malleus

- AKA hammer

- passes vibrations from eardrum to anvil

81

Q image thumb

Incus

- passes vibrations from malleus to stapes

82

Q image thumb

stapes

- AKA stirrups

- tiny U-shaped bone that passes vibrations from anvil to cochlea

- smallest bone in body

83

Ossicles

- 3 small bones that transmit sound from tympanic membrane to oval window

- in order from external to internal:

  • malleus
  • incus
  • stapes

84

reddened area

Q image thumb

auditory tube

AKA Eustachian tube or pharyngotympanic tube

- connects middle ear to back of nose

- equalizes pressure between midle ear and outside air

85

Q image thumb

round window

- located below where stapes meets oval window

- moves outward as sound moves oval window inward to allow for movement of fluid within cochlea

86

middle hole in structure

Q image thumb

oval window

- membrane between middle ear and vestibule of cochlea

- stapes fits into and vibrates it, transmitting sound into cochlea

87

bony labyrinth

- cavity in petrous region of temporal bone

three parts:

  • semicircular canals
  • vestibule
  • cochlea

88

#14

Q image thumb

Vestibule

- detects acceleration and deceleration of head via macula

- central part of bony labyrinth

-contains utricle and saccule, egg-shaped parts of membranous labyrinth

89

#1, #7, and #8

Q image thumb

semicircular canals

- contain three loops of fluid-filled tubes attached to cochlea via vestibule

- detect rotational head movement via crista ampullaris

90

Portion of structure at right containing 5, 6, 12 and 13

Q image thumb

cochlea

- contains spiral-shaped, fluid-filled inner ear structure

- detects vibration of sound waves and creates nerve impules

91

membranous labyrinth

- series of membranous sacs and ducts that fit within the bony labyrinth

- 3 main parts:

  • Semicircular Ducts
  • Utricle and Saccule (within vestibule)
  • Cochlear Duct

92

membranous labyrinth structures

Q image thumb

semicircular ducts

- detect rotational movement of head

 

93

#9, 3 and 2

Q image thumb

Ampulla

- expanded region of each semicircular duct which contains the sensory structure that detects rotational movement of the head

94

whole structure

Q image thumb

crista ampullaris

- strcture within ampulla that contains receptor hair cells to detect rotational movement of head

95

top part marked A

Q image thumb

cupula

- jelly-like, pointed structure on top of crista ampullaris into which hairs of receptor cells project

96

part of vestibule just at base of semicircular ducts

Q image thumb

utricle

- part of membranous labyrinth within bony vestibule

- contains sensory epithelium to detect gravity and linear acceleration

97

#4

Q image thumb

saccule

- part of membranous labyrinth within bony vestibule

- contains sensory epithelium to detect gravity and acceleration

98

whole structure

Q image thumb

Macula

- within utricle and saccule

- contains receptor cells (hair cells) with cilia (many stereo-, one kino-)

- monitor the position of the head when still (static equilibrium) and moving linearly

- cilia of cells stick into otolithic membrane

99

this is a cross section of which portion of the membranous labyrinth?

Q image thumb

cochlear duct

- AKA scala media

- contains receptors for hearing

100

Which nerve innervates the inner ear and what are its two branches?

Vestibulocochlear Nerve (VIII)

- vestibular branch

- cochlear branch

- seen below in yellow

 

A image thumb
101

blue area

Q image thumb

scala vestibuli

- superior chamber of bony labyrinth of cochlea

102

black arrow

Q image thumb

vestibular membrane

- roof of cochlear duct between it and scala vestibuli

103

#3

Q image thumb

scala tympani

- inferior chamber of bony labyrinth of cochlea

104

complex structure within central chamber

Q image thumb

Spiral Organ or Organ of Corti

- at floor of scala media

- contains hearing receptors in thick sensory epithelium

105

the light blue part underlying the complex structure

Q image thumb

basilar membrane

- sheet fibers which support the organ of Corti

- pressure waves in the fluid of the inner ear cause this membrane to bounce, disrupting the sensory cells above it

106

whole brown structure

Q image thumb

hair cell

- cells of organ of corti with many apical stereocilia which detect sound via vibrations

107

#6

Q image thumb

tectorial membrane

- gelatinous structure over hair cells in the organ of corti

- keeps hair cells in place via their embedded cilia which bend when vibrated, causing them to release neurotransmitters

108

- fluid within chambers 2 and 3

Q image thumb

Perilymph

- fluid in the bony labyrinth which surrounds and protects the membranous labyrinth

- continuous with CSF in subarachnoid space

 

109

fluid within cavity 1

Q image thumb

endolymph

- clear fluid in membranous labyrinth

- pictured here in cochlear duct, but is also in utricle, saccule and semicircular ducts

110

Auditoy Pathway of Organ of Corti

  1. Cochlear Nerve axons go to...
  2. Medulla oblongata...
  3. Inferior Conniculus (of midbrain)...
  4. Thalamus...
  5. Temporal lobe of cerebral cortex (primary auditory cortex)

111