Histology of the Visual, Vestibular and Auditory Systems Flashcards
List the different chambers in the eye.
- Anterior Chamber (In front of Iris)
- Posterior Chamber (Between Iris and Lens)
- Vitreous Cavity (Behind Lens)
Describe the three tunicas in the eye.
What is the Limbis?
- Outer –> Sclera (white part) and Cornea
* *Limbis:** Transition from Sclera to Cornea - Middle (Uvea) –> Choroid, Ciliary Body and Iris
- Inner –> Outer Pigmented Layer and Retina
CORNEA!
Corneal Epithelium (STRATIFIED) and Corneal Endothelium (SIMPLE)
Which structure will anchor the Corneal Epithelium to the Bowman’s Layer?
Which cells are within the stromal layer?
Hemidesmosomes
Fibroblasts
What is the most common form of tissue alltransplantation?
CORNEA TRANSPLANT (success rate of OVER 90%)
Ciliary Body has a muscle named the Ciliary Muscle (that will attache to Zonula Fibers)
- *Ciliary processes** are responsible for producing the Aqeuous humor (for the Anterior and Posterior Chambers)
- Circulates around the pupil and to the Trabecular Meshwork
BOTH layers of the Iris are PIGMENTED (*** NO epithelial lining on the anterior, but there is an epithelial lining posterior!)
Describe the two muscles that are associated with the Iris.
- Dilator Pupillae –> Causes pupil dilation (Mydriasis) and innervated by SYMPATHETICS
- Sphincter Pupillae –> Causes pupil constriction (Miosis) and innervated by PARASYMPATHETICS
Name the various layers in the Retina.
Axons from the Ganglion cells are going to converge to form the OPTIC NERVE!
Bipolar Cells are going to be in the INNER NUCLEAR layer
- Horizontal Cells: Communicate between Photoreceptor Cells
- Amacrine Cells: Communicate between Bipolar cells and Ganglion Cells
- Muller Cells: Will span the entire retina
Nuclei of the Photoreceptor cells are in the OUTER NUCLEAR layer
Pigmented epithelium is bound together by TIGHT JUNCTIONS
Where is the spot in the retina where the many layers are pushed away to the side and it can concentrate the greatest amount of light (in order to see a very clear image)?
Fovea Centralis
What is the “blind spot” in the eye?
OPTIC DISC
*** NO photoreceptor cells because there is only AXONS in this part!
Describe detachment of the Retina.
Seperation of two layers of the retina
Differentiate between rods and cones.
Rods –> Light and Dark
Cones –> Color
Describe the clinical significance of Color Blindness.
Describe the path of the aqeuous humor.
Ciliary Process –> Around Iris –> Trabecular Meshwork –> Canal of Schlemm –> Episcleral Veins
What happens if you can’t get rid of the Aqueous Humor due to a blockage?
Glaucoma –> Obstruction of aqueous humor that causes an increase in intraoccular pressure. Produces pain and nausea. Either by blockage of the Canal of Schlemm (most common) or inflammation preventing aqueous humor from reaching the trabecular meshwork
Differentiate between the different regions of the lens
- Anterior Lens - Clear and NO mitosis is taking place
- Going towards Equitorial Region - Mitosis taking place
- Cortical Lens - Where the Zonula Fibers are attaching
*** The deeper you get into the lens, the more flattened your cells will be!
What happens if the lens become Opaque?
CATARACTS!
Opacity of the lens caused by change in the solubility of lens proteins. Impairs vision. Result of aging and diabetes)
When you blink, you are going to send lacrimal fluid in which direction and to which structure?
MEDIALLY to the LACRIMAL LAKE!
Talk about the different glands in the eyelid.
What is the purpose of the conjunctiva?
- Tarsal Glands –> produces wax-type secretion that is going to hold lacrimal fluid on the conjunctiva
- Moll’s Glands –> Associated with the HAIR of the Eyelash!
Conjunctiva: Stratified Columnar Epithelium with mucus-secreting goblet cells. Going to produce a secretion to protect the CORNEA. Bulbar (on the eye) and Palpebral (on the eyelid) Conjunctiva
Differentiate between Subconjunctival hemorrhage and Pink eye.
Subconjunctival Hemorrhage –> Blood flowing UNDERNEATH the conjunctiva
Conjunctivitis (Pink Eye)
ELASTIC CARTILAGE!
What is located in the middle ear?
Malleous - Incus - Stapes (sits within the Oval Window)
What are the two muscles assoicated with the middle ear?
- Stapedius
- Tensor Tympani Muscle (associated with the Malleus)
