8 Flashcards
is a complex organ, with parts derived from ectoderm and mesoderm in the head
region.
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 - cornea and sclera
b. Vascular tunic - choroid, ciliary body and ciliary processes and iris
c. Nervous tunic - retina
cornea and sclera
Fibrous tunic
choroid, ciliary body and ciliary processes and iris
Vascular tunic
retina
Nervous tunic
The anterior compartment is composed of
anterior and posterior chambers that contain
aqueous humor.
The posterior compartment consists of the
vitreous chamber that contains vitreous
humor.
Both eyes develop from the
Optic field
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
Lens fibers
Cells in the outer or superficial pole of
the lens form a single layer of cuboidal or columnar epithelium called
Lens epithelium
The lens
fibers and lens epithelium produce lens proteins called
Crystallins
later on the corneal endothelial cells secrete
Hyaluronic acid
That destros the hyaluronic acid
hyaluronidase
is the reduced opening of the optic cup
Pupil
is derived from the thickened choroid
ectomesenchyme and caudal part of the overlapping portion of the optic cup.
Ciliary apparatus
Sorrounding the optic cup
Ectomesenchymal cells
which differentiates into the inner vascular later of the
wall called
choroid
outer fibrous layer called
sclera
In chick, 14 bony rings called
sclera ossicles
surround the outer margin
of the cornea.
Sclera ossicles
Formed by upper and lower folds of ectoderm (skin), each fold includes a mesenchyme
core.
Eyelids
Derived from the space between the eyelid and the cornea.
Conjunctival Sac
Develops by invagination and budding of conjunctival ectoderm
Lacrimal Gland
Optic vesicle of Dog and Cow
17 days of gestation
25- 30 days of gestation
Optic cup of Dog and Cow
19 days of gestation
30 days of gestation
Lens vesicle of Dog and Cow
25 days of gestation and 30 days of gestation
Fused eyelids of Dog and Cow
33 days of gestation and 50 days of gestation
Opening of eyelids of Dog and Cow
14 days after birth and At birth
Rods and cornea of retina of Dogs and Cow
16-35 days after birth and 150-180 days of gestation
development of a single eye in the center of the head due to failure of the optic
field to separate into 2 lateral eye-forming regions
Cyclopia
absence of eye due to failure of optic vesicles to form or to severe inference
w/ normal growth of optic cup.
Anophthalmia
a defect due to failure of the optic fissure to close.
Coloboma
small undeveloped eye; results from failure of the vitreous body to exert
sufficient pressure for growth, often because a coloboma allowed vitreous humor to escape.
Due to Vit. A deficiency in the mother. Common in pig, dog and cattle.
Microphthalmia
medial deviation of the eyeball. Common in Siamese Cat
Medial strabismus -
contains sense organs for hearing (cochlea) and detecting
head acceleration (vestibular apparatus or vesticule), the latter is important in
balance. Innervated by the cochlear and vestibular divisions of cranial nerve VIII.
Inner or Internal Ear
contains bones (ossicles) that convey vibrations from the tympanic
membrane (ear drum) to the inner ear.
Middle Ear
channels sound waves to the tympanic membrane.
Outer or External Ear
_______of incubation in chick embryo, the surface ectoderm overlying the
dorsolateral wall of myelencephalon by___________
35hrs
Placode formation
of incubation, the otic placodes invaginate to form auditory pits
38hrs
of incubation the otic cup closes and separates from
the ectoderm (vesicle formation) forming an otic vesicle (otocyst)
50hrs
consists of the tympanic membrane, tympanic cavity, auditory
ossicles and auditory tube or Eustachian tube.
Middle ear
The external ear canal develops from the
1st branchial groove
flanking the 1st branchial groove expand laterally to form the
wall of the canal.
VA 1 and VA 2
is composed of the nasal cavity, alae or wings, bridge, nostrils or anterior
nares, choanae or posterior nares, nasal septum and nasolacrimal duct.
Nose
is the part of the nose that contains the nasal conchae.
nasal cavity
It is divided into
right and left chambers by the
Nasal septum
is derived from VA 1 and VA 2
Pinna
Anterior opening of nasal pit
anterior nares
Posterior opening of nasal pit
posterior nares
in the midline cephalic to the stomodaeum gives off
ectomesenchyme cell to areas between the nasal pits to form the frontal prominence
Frontonasal mesenchyme
That develops into the bridge of the nose
Frontal prominence
Becomes the nose wings
Lateral nasal processes
Right and left medial nasal processes fuse w/ the maxillary processes of the right and left
visceral arches 1 to form the
Nasal septum
between the lateral nasal process and the maxillary process of the visceral
arch 1 deepens to form the nasolacrimal groove.
Depression
are groups of specialized (chemoreceptive) epithelial cells localized
principally on the papillae of the tongue.
Taste Buds
Innervate the taste buds
Cranial nerve VII and IX
