Topic # 8 Flashcards
- is a complex organ, with parts derived from ectoderm and mesoderm in the head
region
eye
Parts of the Adult Eye
- Eyeball
- Muscles of the eye
- wall, anterior compartment, posterior compartment and lens.
Eyeball
- intrinsic and extrinsic muscles
Muscles of the eye
The wall of the eye consists of three layers or tunics
a. Fibrous tunic
b. Vascular tunic
c. Nervous tunic
- cornea and sclera
Fibrous tunic
- choroid, ciliary body and ciliary processes and iris
Vascular tunic
- retina
Nervous tunic
is composed of anterior and posterior chambers that contain
aqueous humor.
The anterior compartment
The posterior compartment consists of the vitreous chamber that contains
vitreous
humor
eyes develop from the
optic field
Through tissue interaction between the optic field
and the head mesoderm, the single optic field separates into bilateral (2)
lateral eye-forming
regions
After formation of the five (5) brain vesicles the two (2) lateral eye-forming regions
associated w/ the diencephalon evaginate laterally to become bilateral
optic vesicles
, which connects w/ the diencephalon through the optic stalk, invaginates to form a doublewalled optic cup and the original lumen of the optic vesicle becomes slit-like
The optic vesicle
The outer wall of the optic cup thins out to become the
pigment layer of the retina.
The inner wall of the optic cup collapses and thickens to become
the sensory
(rods and cones) layer of the retina.
During invagination of optic cup a gap along the optic stalk,the ________
is created
choroid or optic fissure,
The vitreous or posterior compartment develops from the
concavity of the optic cup
The vitreous or posterior compartment develops from the
concavity of the optic cup
is formed from ectomesenchyme that
enters the compartment through the optic fissure
the vitreous body
The
surface ectoderm overlying the optic vesicles, by induction from the optic vesicles and placode
formation, thickens to form the
lens placode.
cells in the deep or inner pole of the lens elongate to form_______ that push
toward the cavity of the lens vesicle, almost obliterating it.
lens fibers
Cells in the outer or superficial pole of
the lens form a single layer of cuboidal or columnar epithelium called
lens epithelium
Cornea develops from 2 sources:
corneal epithelium
Surface ectoderm
Surface ectoderm that overlies the invaginated lens
vesicle, by induction from the
lens vesicle and optic cup
forms a 2-cell thick (basal and superficial)
corneal epithelium;
secrete a collagenous matrix called primary stroma
the basal cells
later on the corneal endothelial cells secrete into______ the primary
stroma causing it to swell
hyaluronic acid