Anatomy W11 - The Eye Flashcards
What is the pupil of the eye?
An opening where light enters the eye to reach the retina
What is the iris of the eye?
A diaphragm that regulates the diameter of the pupil and controls the amount of light entering the eye.
In health, how should the eyelid appear in relation to the iris?
The eyelid should cross the upper iris (no sclera seen above the iris)
In disease i.e. hyperthyroidism, how does the eyelid appear in relation to the iris?
Sclera can be seen all the way around the iris giving a staring look.
What is the lacriminal caruncle? Where is this found?
This is a fleshy papilla found at the medial end of the eye.
What is sclera?
The white outermost coating of the eye - covered by conjunctiva (mucous membrane).
What is conjunctivitis?
Red and itchy eyes caused by Infection of the conjunctiva, mucous membrane covering the eye.
Very contagious
What is the purpose of the curvature of the hairs of the eyelashes?
Prevents the upper and lower eyelashes from sticking together when eyes are closed.
Where are the follicles of the eyelashes situated on the eyelid?
The outer square of the eyelid.
What is a stye?
An infection of the eyelash follicle
What are meibomian glands?
What is there purpose?
Exocrine glands on the eyelid that produce oily secretions
Maintains tears within the eye and prevent tears spilling out.
Prevents the film of tears from evaporating
What is a mebomian cysts?
Where the meibomian gland on the eyelid gets blocked by the oily secretions and forms a cyst.
Where is the lacrimal gland situated?
above the lateral end of the eye
How many ducts does the lacrimal gland have?
Many - into the teens
Where do tears from the lacrimal gland drain into?
The conjunctival sack (sack between the front of the eyelid and the eye)
What is the lacrimal punstum?
An opening to the lacrimal canaliculus ducts on the upper and lower eyelid facing into the tears
Describe the course of excess tears from the conjunctival sack.
Tears enter the lacrimal canaliculus via the lacrimal punstrum.
From the canaliculus the tears enter the lacrimal sac
The lacrimal sac then enters a canal in the bone called the nasolacrimal duct
The nasolacrimal duct opens up into the inferior meatus of the nasal cavity.
Tears drain from the nose
What can happen in trauma to the medial end of the eye?
Damage to the lacrimal canaliculus which creates a fistula where tears can escape into the surrounding structures.
What is the purpose of the blink reflex?
Ensures that there is a film of tears covering the front of the eye and that the cornea is always moist.
List pathology of the eyelid.
Stye
Meibomian cyst
Cyst of moll
What is a cyst of moll?
Where there is a blockage of the apocrine sweat gland of moll.
How do you differentiate between a meibomian cyst and a cyst of moll?
Cyst of moll appears like a watery bag
Meibomain gland appears as if its deeper within the tissues and NOT watery looking
What lymph nodes will be enlarged in infection i.e. stye of the eyelids?
The parotid lymph nodes
