Test 3 The Special sense Flashcards
(125 cards)
1
Q
What are the special senses of the human body?
A
- smell
- hearing
- equilibrium
- taste
- sight
2
Q
where are the special sensory receptors located?
A
localized and confined to the head region
3
Q
the chemical senses
A
- olfaction
- gustation
4
Q
Where does the taste receptors occurs?
A
in the taste buds in the mucosa of the mouth and pharynx
- tongue palate, inner cheeks
5
Q
how many taste buds do we have?
A
10000
6
Q
most taste buds occur in?
A
papillae
7
Q
what is papillae
A
two types of peg like projections of the tongue mucosa
8
Q
the two types of papillae
A
fungiform papillae
circumvallate papillae
9
Q
fungiform papillae
A
- small
- occur over the entire surface of the tongue
10
Q
circumvallate papillae
A
- large
- arranged in an inverted V near the back of the tongue
11
Q
where does the taste buds occur?
A
within the epithelium that covers the papillae, on the apical surface of fungiform papillae, and in the side walls of the circumvallate papillae
12
Q
each taste bud is a globular collection of
A
50-100 epithelial cells that resemble a closed tulip
13
Q
each taste bud consists of how many major cell types and what are they?
A
3
- supporting cell
- gustatory cell
- basal cells
14
Q
supporting cells
A
- most abundant
- insulates the gustatory taste cells from each other and from the surrounding epithelium of the tongue
15
Q
gustatory cells
A
receptor cells
16
Q
basal cells
A
- immature cells
- regularly replace the other two cell types
17
Q
sensory nerve fibers enter the taste buds and synapse with?
A
the receptor cells
18
Q
long microvilli project from? and extend through?
A
- project from receptor cells and supporting cells
- extend through a taste pore to the surface of the epithelium
19
Q
cells of taste buds are replenished every?
A
7-10 days by the division of the basal cells
20
Q
taste information reaches the brain stem and cerebral cortex through the?
A
gustatory pathway
21
Q
where does the sensory fibers carrying taste information from the tongue primarily occur?
A
in two cranial nerves
- facial nerve (VII)
- glosspharyngeal nerve (IX)
22
Q
facial nerve VII
A
transmits impulses from taste reeptors in the aneterior two - thirds of the tongue
23
Q
glossopharyngeal nerve IX
A
carries sensations from the tongues posterior one third
24
Q
tthe receptors for smell are part of??
A
olfactory epithelium that overs the superior nasal concha and the superior part of the nasal septum
25
what kind of epithelium is olfactory epithelium
pseudostratified columnar
26
olfactory epithelium contains and surrounded by?
contains millions of bipolar cells called olfactory receptor cells and surrounded by columnar supporting cells
27
basal cells
- at the base of the epithelium; short
| - undifferentiated cells that continually form new olfactory receptor cells
28
where the cell bodies of the olfactory receptor cells located?
olfactory epithelium
29
each receptor cell has?
an apical dendrite that projects to the epithelial surface and ends in a knot from which long olfactory cilia radiates
30
the surface of the epithelium is coated with?
a layer of mucus secretd by the supporting cells and olfactory glands in the underling CT
31
what is the function of the cilia?
move objects
32
what is the function of the mucus
captures and dissolves odor molecules from the air
| and it is contantly renewed
33
olfaction axons gather into nerve bundles called?
filaments of the olfactory nerve (cranial nerve 1), which penetrate the cribiform plate of the eithmoid bone and enter the overlying olfactory bulb of the forebrain
34
what happens in the olfactory bulb
the olfactory nerve axons branch profusely and synapse with neurons called mitral cells in complex synaptic clusters called glomeruli
35
what does mitral cells do?
relay olfactory information to other parts of the brain
36
how many % of the receptors are in the eye
70%
37
how much p% of the cerebral cortex is involved in processing visual information
40
38
the ratio of the visible eye
1/6 of the eyes surface is visible
39
accessory structures
```
eyebrows
eyelids
conjunctiva
lacrimal apparatus
extrensice eye muscle
```
40
eyebrows
consist of corase haris in the skin on the brow ridges of the skull
41
eyebrows function
shade the eyes from sunlight and prevent persperiatieyelids (on from running down the forehead from reaching the eyes
42
eyelids (palpebrae)
the upper and lower lids are separated by the palpebrae's fissure (eye slit) and meet each other at the medial and lateral angles (canthi)
43
lacrimal caruncle
reddish elevation at the medial canthus
44
tarsal plates
connective tissue within the eyelids that serves as attachment sites for obicularis oculi
45
eyelashes
project from the free margin of each eyelids
46
what are the glands in the eyelids
tarsal glands
| cilliary glands
47
tarsal glands
modified sebacious glands embedded in the tarsal plates
| - produces oil that spreads over the entire surface of the eye, slowing the evaporation of water
48
ciliary glands
associated with the hair follicles of eyelashes
49
infection of tarsal gland
chalazion "swelling"
50
infection of ciliary glands
sty
51
conjunctiva
vascularized transparent mucous membrane that covers the inner surfaces of the eyelids and folds back over the anterior surface of the eye
52
palpebral conjuctiva
cover the inner surfaces of the eyelids
53
bulbar conjuctiva
a very thin membrane that covers the white of the eye but not the cornea
54
when the eye is closed, the slitlike space that forms between the eye surface and the eyelids is the?
conjunctival sac
55
conjunctiva consists of?
stratified columnar epithelium underlain by a thin lamina propria of loose connective tissue
56
conjunctivitis
inflammation of the conjunctiva that causes them to appear red
- red eye/pink eye
57
lacrimal aparatus
- lacrimal gland
| - lacrimal sac
58
lacrimal gland
```
produces lacrimal fluid
- The lacrimal glands are superior
to the lateral aspect of each eye.
They continually release a dilute
salt solution (tears) that flows onto
the anterior surface of the eyeball.
```
59
lacriml sac
fluid empties into nasal cavity
60
the tear flush across the eyeball into the?
lacriminal canals medially then into the lacrimal sac, and finally into the nasolacrimal duct which empties into the nasal cavity
61
the lacrimal secretion contains?
lysozyme, an antibacterial enzyme
| that cleans and protects the eye surface as it moistens and lubricates it
62
six muscles that control movement of the eye
- Originate in the walls of the orbit
- Insert on outer surface of the eyeball
- Annular ring – origin of the four rectus muscles
63
the wall of the eye is constructed of three tunics or coats, what are they?
1) Fibrous tunic
2) Vascular tunic
3) Sensory tunic
64
The outermost fibrous tunic is a
1) protective layer composed of dense
| avascular connective tissue
65
the two different regions of fibrous tunic
-The opaque white sclera forms the posterior 5/6 of the tunic.
Provides shape and an anchor for eye muscles
-The anterior-most portion is the transparent cornea, through which
light enters the eye.
66
The sclera part of the limbus contains a
large vessel called the scleral
| venous sinus that drains aqueous humor out of the eye.
67
The transparency of the cornea is due to? and Corneas function is?
The transparency of the cornea is due to the regular alignment of
collagen fibers.
- Function: protection; allow light to pass into the eye; forms part of
the light-bending apparatus of the eye
68
the cornea is avascular so where does the cornea get oxygen and nutrients?
front - air through cornea
| back - coriod coat
69
-Touching the cornea causes
reflexive blinking and an increased
secretion of tears.
-The cornea has the ability for regeneration
70
the vascular tunic has three parts
choroid
cilliary body
iris
71
• Choroid coat:
the blood-rich nutritive layer, highly pigmented layer
that forms the posterior 5/6 of the eye.
- The blood vessels nourish the other tunics
72
The brown color is due
to the presence of melanin which helps
absorb light…preventing light from scattering within the eye and
creating visual confusion.
73
ciliary body
thickened ring of tissue that encircles the lens
- Composed of smooth muscle called ciliary muscle which act to
focus the lens
74
Ciliary processes:
posterior surface of the
| ciliary bod
75
Ciliary zonule
| (suspensory ligament):
Attached around entire
| circumference of the lens
76
• Iris:
the most anterior part of
the vascular tunic; visible
colored part of the eye
- base is attached to the ciliary body
77
iris contains
```
Contains both circularly
arranged and radiating smooth
muscle, the sphincter and
dilator pupillae muscles, that
act to vary the size of the pupil
```
78
pupil
the round, central opening of the iris.
| -Allows light to enter the eye
79
iris eye color
```
All people (except albinos) have a layer of pigmented cells on the
posterior surface of the iris.
Vascular Tunic: Iris/Eye Color
-Although irises come in
many colors… they contain
only brown pigment.
```
80
eye colors
-Brown eyes: pigmented cells on the posterior surface of the iris +
pigment cells in the body of the iris
-Blue eyes: pigmented cells on the posterior surface of the iris + no
pigment in the body of the iris
-Hazel eyes: pigmented cells on the posterior surface of the iris +
some pigment cells in the body of the iris
81
the inner most sensory tunic of the eye and its layers
retina.
a) Pigmented layer: single layer of melanocytes
b) Neural layer: contains the photoreceptors, rods and cones,
which begin the chain of electrical events that result in vision.
82
• Lateral to each blind spot, and directly posterior to the lens, is
an area
called the macula lutea (yellow spot), an area of high cone density. In
its center is the fovea centralis, a minute pit which contains mostly
cones and is the area of greatest visual activity.
83
the three main types of neurons of retina
Photoreceptor cells
Bipolar cells
Ganglion cells
84
rods
the specialized receptors
| for dim light (gray tones)
85
cones
```
color receptors that
permit high levels of visual
acuity, but they function only
under conditions of high light
intensity (no color vision is
possible under moonlight)
```
86
ganglion
Ganglion: light must pass
through this layer the bipolar
neuron layer to reach and excite
rods and cones.
87
as a result of light stimulation
```
1) The photoreceptors undergo
changes in their membrane
potential that influence the bipolar
neurons.
2) This then stimulates the
ganglion cells, whose axons leave
the retina in the tight bundle of
fibers known as the optic nerve
```
88
The photoreceptor cells are distributed over the entire neural retina,
except where the optic nerve leaves the eyeball...what is this site called
This site is called the
| optic disc or blind spot.
89
The lens and ciliary zonules (suspensory ligaments) divide the eye
posterior segment cavity
| anterior segment cavity
90
) Posterior segment (cavity)
-Filled with vitreous humor: Clear, jelly-like substance that
transmits light and supports the posterior surface of the lens.
Helps maintain intraocular pressure
91
b) Anterior segment
| (cavity) :
```
Divided into
anterior and posterior
chambers filled with
aqueous humor, which
is renewed continuously,
formed as a blood filtrate,
and supplies nutrients to
the lens and cornea
-Anterior chamber
(between the cornea and
iris)
-Posterior chamber
(between the iris and lens
```
92
the ear
The ear is a complex structure containing sensory receptors for
hearing and equilibrium.
93
the ear is divided into three major areas
outer ear: functions in hearing
- middle ear: functions in hearing
- inner ear: functions in both hearing and equilibrium
94
external ear is composed of?
- auricle (pinna)
- external acoustic meatus
- tympanic membrane.
95
auricle pinna
is the skin-covered cartilaginous structure
encircling the auditory canal opening.
-Function: collects and directs sound waves into the external
acoustic meatus/canal
96
The external acoustic meatus (external auditory canal) is
a short,
narrow chamber carved into the temporal bone.
-Lined with skin and contain hairs, subaceous glands, and ceruminous
glands (secretes wax)
97
middle ear
A small air-filled chamber called the tympanic cavity
| found within the temporal bone
98
tympanic cavity
The tympanic cavity is spanned by three small bones, collectively
called the ossicles (malleus, incus, stapes), which articulate to form a
lever system that amplifies and transmits the vibratory motion of the
eardrum to the fluids of the inner ear via the oval window (deep to
stapes).
99
the smallest bone in the body
the ossicles
100
• Two skeletal muscles occur in
| the middle ear cavity
a) Tensor tympani muscle
b) Stapedius muscle
- These muscles contract
reflexively to limit the vibration
of the ossicles when the ears are
assaulted by very loud sounds.
101
The pharyngotympanic tube (auditory tube)
connects the middle ear
chamber with the pharynx.
-Note: The eardrum doesn’t vibrate properly unless the pressure on
both of its surfaces is the same. The auditory tube allows for the
equalization of the pressure of the middle ear cavity with the external
air pressure.
102
inner ear
The inner ear is a bony labyrinth…a cavity within the
temporal bone consisting of two main divisions:
a) the bony labyrinth
b) the membranous labyrinth
103
Bony labyrinth:
cavity consisting of a system of twisting channels
that has three parts.
-Has three parts: a) semicircular canals, b) vestibule, and c) cochlea
104
Membranous labyrinth
: a continuous series of membrane-walled
sacs and ducts that fit loosely within the bony labyrinth.
-Main parts: a) semicircular ducts, b) utricle and saccule, and c)
cochlear duct
105
the wall of the membranous labyrinth is a
te: “membrane”
| composed of a thin layer of C.T. lined by a simple squamous epithelium
106
The membranous labyrinth is filled with a clear fluid called
| .
endolymph
107
• The bony labyrinth is filled with another clear fluid called
.
perilymph
108
vestibule
• Vestibule: the central cavity of the bony labyrinth. Suspended within
its perilymph are the utricle (“leather bag”) and saccule (“little sac”)
109
utricle is continuous with? the saccule with?
- semicircular duct
| - cochlear duct
110
macula
a: a spot of sensory epithelium found in both the utricle and
saccule.
111
static equilibrium
a: a spot of sensory epithelium found in both the utricle and
saccule.
112
linear acceleration
These receptor cells also monitor straight-line
| changes in the speed and direction of head movements…
113
Each macula is a patch of epithelium
| containing
columnar supporting cells and
scattered receptors called hair cells, which
synapse with sensory fibers of the vestibular
nerve
114
Hair cells have many
stereocilia and a
single kinocilium (“true cilium”) protruding
from its apex.
115
-The hairs are embedded in
an overlying
otolithic membrane…a jellylike disc that
contains heavy crystals of calcium carbonate
called otoliths (“ear stones”).
116
Semicircular canals (anterior, posterior, and lateral):
house
receptors for rotational acceleration of the head…lie posterior and
lateral to the to the vestibule.
117
Anterior and posterior semicircular canals:
lie in the vertical plane
| at right angles
118
lateral semicircular canal: lies in the
horizontal plane
119
Semicircular duct: snakes through each semicircular canal
| -Houses a structure called a
crista ampullaris… has an epithelium
| that contains supporting cells and receptor hair cells
120
The crista ampullaris measures
rotational (angular) acceleration
| of the head
121
The hairs project into a tall,
jellylike mass that resembles a
pointed cap…called the
cupula.
122
The crista within each of the
three semicircular ducts responds
to
head rotation in a different plane
| of space.
123
• The cochlear duct lies between
```
two chambers (scala vestibuli &
scala tympani) and contains receptors for hearingv
```
124
cochlear duct chambers
The vestibular membrane: the roof of the cochlear duct
| -The basilar membrane: the floor of the cochlear duct
125
• The cochlear duct contains receptors for hearing:
- The spiral organ of Corti is the receptor epithelium for hearing and
consists of supporting cells and the inner and outer hair cells
(receptor cells).
