Special Senses: Vision Flashcards
How many percent of the sensory receptors are found in the eyes?
70%
What are the special senses?
Smell Taste Sight Hearing Equilibrium
What protects the eye?
Bony orbit Cushion of fat
In what week does the optic vesicle forms the optic cup?
Early 4th week
In the early fourth week, the optic vesicle divides to form a two-layered _______
Optic cup
In the early fourth week, the overlying ectoderm forms a _______?
Lens pit
In what week does the overlying ectoderm forms the lens pit?
Early fourth week
In what week does the optic cup deepens and forms inner and outer layers?
Late 4th week
In the Late fourth week, the lens pit forms _______?
Lens vesicle
In what week does the lens pit forms the lens vesicle?
Late 4th week
In what week does the lens becomes an internal structure?
6th week
In what week does the corneas, sclera and choroid starts to form?
6th week
What starts to form in week 6?
Cornea Sclera Choroid
In what week does the three tunics of the eye is formed?
Week 20
What forms in week 20?
Three tunics of the eye
Layer of the eyeball that includes the sclera and cornea
Fibrous tunic - Corneoscleral coat
A vascular layer that includes choroid, ciliary body and iris
Uvea
Third layer of the eyeball that includes an outer pigment epithelium and an inner neural layer
Retina
What are the three layers of the eyeball?
Fibrous tunic Vascular tunic Retina
Consists of dense, irregular connective tissue, making it opaque
Sclera
Covers the anterior 1/6th of the eye and is continuous with the fibrous sclera posteriorly
Cornea
How many layers does the cornea have?
5
What are the 5 layers of the cornea?
- Stratified squamous non keratinizng corneal epithelium 2. Bowman’s membrane 3. Corneal stroma (substantia propria) 4. Descemet’s membrane 5. Simple squamous, corneal endothelium
The corneal endothelium is lined by what epithelium?
Simple squamous
What type of collagen fibers makes up the stroma of the cornea?
Type 1 collagen
What are the cells that makes up the stroma of the cornea?
Keratocytes
True or False: The stroma of the cornea is vascular.
False. The stroma is avascular.
Where transparent corneal stroma merges with opaque, vascular sclera
Limbus or corneoscleral junction (CSJ)
Contains scleral venous sinus or canal of Schlemm, which receives aqueous humor from anterior chamber
Stroma of limbus
Also known as the canal of Schlemm
Scleral venous sinus
Also known as the Scleral venous sinus
Canal of Schlemm
Helps to reduce glare within the eye
Melanin pigment
Consists mainly of choroid and has a dark brown color that has many venous plexuses and capillaries
Uvea
Extends inwards to form a ring-like thickening
Ciliary body
Ligament that arises from ciliary process
Suspensory ligament of the lens or the Zonular ligament
The __________ continuous posteriorly until it merges with the retina at ora serrata
Ciliary body
The ciliary body continuous posteriorly until it merges with the ___________ at ora serrata
Retina
The ciliary body continuous posteriorly until it merges with the retina at __________
Ora serrata
Cells that are prominent in suprachoroidal lamina
Melanocytes
Melanocytes are prominent in what lamina?
Suprachoroidal lamina
Choroid’s inner region, _______________ lamina, has a rich microvasculature
Choroidocapillary lamina
A thin layer located between the choroid and retina
Bruch’s layer
What is the outer layer of the retina?
Pigmented layer
Extends over the anterior surface of the lens from the anterior border of the ciliary body
Iris
How many layers does the iris have?
5 layers
What are the 5 layers of the iris?
- Discontinuous layer of fibroblast and melanocytes 2. Avascular anterior stromal sheet (lamella) 3. Vascular layer of LCT forming the bulk of the iris 4. Posterior membrane, containing the circular sphincter pupillae and radial dilator pupillae muscles 5. Double layer of pigmented epithelium
What layer of the iris is composed of a discontinuous layer of fibroblasts and melanocytes?
First
What layer of the iris is composed of an avascular anterior stromal sheet?
Second
What layer of the iris is composed of a vascular layer of LCT which forms the bulk of the iris?
Third
What layer of the iris is composed of forms the bulk of the iris?
Third
What layer of the iris is composed of the posterior membrane?
Fourth
What layer of the iris is composed of 2 muscles?
Fourth
What layer of the iris is composed of the circular sphincter pupillae and radial dilator pupillae muscles?
Fourth
What layer of the iris is composed of a double layer of pigmented epithelium?
Fifth