Special Senses Flashcards
responsible for sensing and maintaining balance and inter and
maintaining balance and interpreting linear and angular acceleration
inner ear
Taste is detected by the
taste buds in the
oral cavity
This coat consists of the opaque posterior four-fifth, the sclera and the anterior transparent one-fifth, the cornea
Outer Fibrous Coat
Outer Fibrous Coat also known as
Sclerocorneal Layer
a dense regular connective tissue resembling that of ligaments and tendons, provides
rigid structural support for the eyeball
sclera
Sclera is separated externally from
Tenon’s capsule
Sclera is separated internally from
choroid
Tenon’s capsule aka
fascial sheath of eyeball
Sclera is separated externally from Tenon’s capsule (fascial sheath of eyeball) by
episcleral layer of loose connective tissue (Tenon’s space)
Sclera is separated internally from chorid by
lamina fusca (suprachoroidal lamina)
Its rich sensory nerve supply (from the ophthalmic branch of cranial nerve ____) is sensitive to touch and pain
V
a prominent basement membrane,
8-15 µm thick—that binds epithelium to underlying connective tissue
Bowman’s membrane
The thick central region, the
______, contains 60-70 layers of type I collagen fibers, which are uniform in diameter and embedded in a proteoglycan-rich extracellular matrix
substantia propria
______—misnamed ______—lines the posterior surface
Simple cuboidal epithelium; corneal endothelium
Cornea’s basement membrane (10-12 µm thick) is .
Descemet’s membrane
The boundary between cornea and sclera (white of the eye) is an abrupt transitional zone, the _____, where mucous membranes covering
the sclera (bulbar conjunctiva) and underside of the eyelid (palpebral conjunctiva) join the anterior corneal epithelium.
limbus
marked by a shallow depression externally and it is the place where
the transparent cornea becomes continuous with the opaque sclera.
sclerocorneal junction
It contains an important circular canal lined by endothelium called _____ concerned with drainage of aqueous humour
canal of Schlemm
canal of schlemm aka
scleral venous sinus
dialysate of blood
Aqueous humour
a clear watery fluid
(similar to CSF in composition) produced by the ciliary epithelium, covering the ciliary processes
into the posterior chamber
Aqueous humour
serves as a medium for exchange of metabolites to and from the avascular lens and cornea
Aqueous humour
a heavily pigmented vascular coat that absorbs light that has passed through the retina, creating a dark chamber for the eyeball.
Middle Vascular Pigmented Coat
Middle Vascular Pigmented Coat aka
Uveal Tract
- the posterior part of the middle coat and lies between sclera and retina.
Choroid
- it is rich in small blood vessels and pigment cells, which give a purple black color to this coat.
Choroid
Loose connective tissue rich in melanocytes
Suprachoroidal layer
Loose connective tissue rich in melanocytes and medium-sized
blood vessel
Vascular layer
Capillary network essential for nourishment of retina
Choriocapillary layer
Refractile hyaline layer forming basement membrane of the
pigment epithelium of retina
Bruch’s membrane (glossy membrane)
a circumferentially thickened part of the middle coat extending from the ora serrata to the edge of lens
ciliary body
cilial body’s anterior part presents radially oriented ridges called _____ and they give attachment to the suspensory ligament (zonule) of lens
ciliary processes
cilial body is mainly formed by ____ (smooth muscle) oriented in
longitudinal, circular and radial directions
ciliary muscle
is the forward prolongation of nonsensitive part (ciliary part) of retina beyond the ora serrata
Ciliary epithelium
the ____ is the pigmented cuboidal epithelium and is continuous
with the pigment epithelium of retina
superficial layer
the ____ is the nonpigmented columnar epithelium which is continuous with the nervous layer of retina at the ora serrata
deep layer
It forms a pigmented circular diaphragm placed in
front of the lens with an aperture in the center, the pupil
iris
is circularly arranged near the pupillary margin of the iris and it
causes constriction of pupil.
Sphincter pupillae (smooth muscle)
radially arranged and causes dilation of pupil.
Dilator pupillae
The color of the eye depends on the amount of
stromal pigment
- the innermost coat of the eyeball
- is soft, translucent and pinkish red in color in fresh
unbleached stat
retina
retina aka
Inner Photosensitive Coat
The ______ is sensitive to light and is called the optic part of retina, which extends from the optic disc to a scalloped margin behind the ciliary
body, the ora serrata
posterior three-fourth
The _____ is nonsensitive to light and it lines the ciliary body (ciliary part of retina) and the posterior surface of the iris (iridial part of retina) as a double layer of epithelial cells.
anterior one-fourth
DISTINCT LAYERS: arranged in parallel, is a prominent, fibrillar layer that comprises the
outer photoreceptor segments
layer of rods and cones
DISTINCT LAYERS: the line formed by junctional complexes between
photoreceptors and supportive (Müller) cells
external limiting membrane
DISTINCT LAYERS: a lightly stained zone, represents synaptic areas between
photoreceptors and dendrites of bipolar cells.
outer plexiform layer
DISTINCT LAYERS: marks the middle nucleated parts of rods and cones, which are
arranged in palisade manner
outer nuclear layer
DISTINCT LAYERS: contains mostly cell bodies of bipolar cells, other associated neurons, and
nuclei of Müller cells.
inner nuclear layer
DISTINCT LAYERS: contains mostly cell bodies of bipolar cells, other associated neurons, and
nuclei of Müller cells.
inner nuclear layer
DISTINCT LAYERS: a relatively thick synaptic region, mostly between bipolar cells and ganglion cells, that also holds amacrine cell processes spreading laterally as interconnecting
neurons.
inner plexiform layer
DISTINCT LAYERS:
- contains cell bodies of multipolar ganglion cells
- their dendrites branch in the inner plexiform layer, and their axons enter the next layer.
ganglion cell layer
DISTINCT LAYERS: comprises ganglion cell axons, about 1 million in each retina, that course
radially toward the optic nerve
nerve fiber layer
DISTINCT LAYERS: the thin basal lamina of Müller cells, marks the boundary between neural retina and vitreous body
internal limiting membrane
The visual axis of the eyeball passes through a depression in the retina called
fovea centralis
Fovea is surrounded by an oval yellow pigmented area called
macula lutea
It is the area through which optic nerve leaves the retina, pierced by central vessels of retina, and
considered to be the blind spot of retina as here photoreceptors are absent
optic disc or optic papilla.
About 4 mm medial to fovea centralis the retina shows a round pale pink area called
optic disc or optic papilla.
a spiral canal shaped like a snail shell, is embedded in temporal bone.
cochlea
The cochlear duct is filled with______; _____fills the other two scalae.
- endolymph; perilymph
The scalae vestibuli and tympani communicate through the____, a small opening at the cochlear apex.
- helicotrema
a richly vascularized pseudostratified epithelium that secretes endolymph.
- stria vascularis
________, which marks the roof of the cochlear duct, consists of two layers of simple squamous epithelium and delineates cochlear duct from scala vestibuli.
- Reissner’s (vestibular) membrane
______are specialized auditory receptor cells.
- Cochlear hair cell
Nerve fibers converge toward the spiral ganglion, which contains cell bodies of neurons of the cochlear part of_______. These bipolar neurons send axons to the brain’s auditory cortex
cranial nerve VIII
______ is a mucous membrane that is highly specialized for smell.
Olfactory mucosa
slender bipolar neurons spanning the width of the epithelium, are receptor cells that bind odoriferous substances and convert them to nerve impulses. They are the only neurons in the body with direct exposure to a body surface
Olfactory cells
The apical dendrite of each cell ends as a_______, which extends above the epithelial surface.
bulbous olfactory knob
Many nonmotile cilia that lie along the epithelial surface emanate from an olfactory knob and increase surface area for______.
odor detection
The _______ is loose, highly vascular connective tissue containing many thin-walled blood vessels and branched tubuloalveolar glands (of Bowman), which take serous secretions via ducts to the mucous membrane surface
lamina propria
_____are ovoid to barrel-shaped clusters of pale-staining cells lying vertically in stratified squamous epithelium
Taste buds
each taste bud has ____ cells, whose arrangement resembles segments of a citrus fruit
50-75
primary receptor neurons in olfactory mucosa
olfactory receptor cells
Anterior surface of the cornea is covered w/ a _______ that is NONKERATINIZED and consists of FIVE or MORE CELL LAYERS
stratified squamous corneal epithelium
- forms the body of the cornea
- consists of parallel bundles of collagen fibers and layers of flat fibroblasts
substania propria
Homogenous anterior limiting
bowman’s membrane
a thick basement membrane located at the posterior portion of the corneal stroma
descemet’s membrane
Posterior surface of the cornea that faces the anterior chamber of the eye is covered with simple squamous epithelium called posterior epithelium, also known as ________
corneal endothelium
____ is a vascular outer layer with loose connective tissue and pigmented melanocytes
- choroid
Deep to the outer nuclear layer is a clear area of synaptic connections known as the
- outer plexiform layer
