Eye Histology Flashcards
Fiborus layer of the eye components
Sclera
Cornea
Vascular layer (uvea) of the eye components
Chorid
Ciliary Body
Iris
Sensory layer of the eye components
Retina
Collagen+ dense connective tissue (fibroblasts, elastic fibers)
Extends from cornea to the optic nerve
What tissue is this?
Sclera
Function: supports eye shape, protects against trauma, surface for attachment of extraocular muscles, protects the more delicate internal structures
Sclera function
Most transparent tissue of the body
External surface layer- stratified squamous epithelium
1mm thick multilayered collagen fibers in the middle
Inner surface layer- endothelium
Cornea
The basement membrane of the cornea (stratified squamous epithelium) is called the what?
Bowman’s Membrane
Uneven cornea is one of the causes for _______
Astigmatism
specialized basement membrane
Nonkeratinized
Sensory –free nerve endings present
Membrane maintains shape of the cornea- protects the stroma underneath from infections
Bowman’s membrane
Endothelium of the cornea has Na+/K+ ATPase pumps present
It’s basement membrane is called the _________
Descemet’s membrane
Highly vascularized connective tissue (fibroblasts)
present in the posterior 2/3rd of the eye ball
Numerous melanocytes- make the black layer
prevent light from entering the eye ball from the sides and helps in limiting the light entry to the pupil only
Choroid
supplies retina with essential nutrients & O2
Choroidocapillary lamina (CCL)
Rests on the sclera
Surrounds the lens
Where the choroid meets the Cornea
Ciliary body
Makes up most of the ciliary body and consists of smooth muscle fibers
Contraction of these muscles affects the shape of the lens and is important in visual accommodation
Ciliary Muscle
Finger-like processes covered by a dual layered cuboidal epithelium
Superficial cells are not pigmented, inner layer is highly pigmented
Core is made of connective tissue
Epithelial function: Secretion of aqueous humor, to take fluids from the blood and transfer them on the other side as aqueous humor due to close proximity to vessels
ciliary processes
What are the 3 steps in the production and removal of the aqueous humor?
- Aqueous humor is secreted by ciliary process into the posterior chamber
- AH moves from the posterior chamber, through the pupil, to the anterior chamber
- Excess AH is resorbed via the scleral venous sinus
Originate from the ciliary processes and attach to the lens capsule
Made up of Fibrillin
Hold the lens in place
Ciliary Zonule
Thin tissue rising from the ciliary body
Leaves an opening in the middle called the pupil
Controls the diameter of the pupil
Stroma is made of loose connective tissue
Epithelial cells that are in contact with the _____ contain melanin forming a pigmented epithelium
Lens
Muscles that control the pupil diameter have ____________ and ___________ innervation
sympathetic; parasympathetic
myoepithelial cells in the iris are?
Dilator pupillae muscle (DPM)
smooth muscles of the iris are?
Sphincter pupillae muscle (SPM)-
Pigmented layer- simple cuboidal cell layer- provides Vit. A
Neural layer- highly stratified- organized in 3 cellular layers
histologically and embryologically it is a part of the CNS
Retina
Neural layer of the retina can be divided into 3 cellular layers. The 3 cellular layers are:
Ganglion cell layer
inner nuclear layer
layer of rods and cones
Receptive in bright light, give a perception of color
Cones
