Vision | Accessory Structures Flashcards
What are the palpebrae and what is their function
Eyelids; keep foreign objects out of the eye
Palpebral fissure
Space between the two eyelids
Canthi
Corners of the eye
Caruncle
The pinkish mound in the canthi that holds sebaceous sweat glands
What are the 5 layers of the eyelid?
1) Skin
2) Aerolar connective tissue
3) Muscle
4) Tarsal Plate
5) Palpebral conjunctiva
What is the tarsal plate?
A dense layer of connective tissue. It helps maintain the shape of the eyelid
What are the two muscles in the eyelid?
Orbicularis Oculi > closes the eyelid
Levator palpebrae > opens the eyelid
Ciliary glands
Lubricate eyelashes
Sty
inflammation of the ciliary glands
Meibomian glands
A sebaceous gland that produces sebum
Sebum
What lubricates eyelids and keeps tears in the eye
Chalazion
An infection of the meibomian glands
Conjunctiva
The mucous membrane in eyelids and exposed part of the eye that lubricates the eye
Palpebral conjunctiva
Conjunctiva on inner surface of eyelids
Bulbar conjunctiva
Conjunctiva on anterior white surface of the eye
Conjunctive fornices
Where palpebral and bulbar conjunctiva meet
Conjunctivitis
Inflammation of conjunctiva
Lacrimal gland
Located on the side above the eye, it produces tears
What are tears made of?
Mostly water, some salts, mucous, and a bacteria-killing enzyme
What are the three lacrimal structures on the inside of the eye?
Lacrimal caniliculi (two small ducts that connect to Lacrimal duct)
Lacrimal duct
Nasolacrimal duct
What are the 6 extrinsic eye muscles?
Superior Rectus Inferior Rectus Lateral Rectus Medial Rectus Superior Oblique Inferior Oblique
H-Test
Clinical test for normal eye movement. If a person can follow the “H” their eye movement is normal.
What are the 3 Tunics (Layers) of the eye?
Fibrous Tunic
Vascular Tunic
Nervous Tunic
What structures does the Fibrous tunic contain?
The sclera
The cornea
What structures does the Vascualr Tunic contain?
Choroid
Ciliary body
Iris
What structure does the nervous Tunic contain?
Retina
What is the sclera and what does it do?
White, outerlayer of eye.
Maintains the shape of the ye, and is an attachment point for eye muscles
What is the cornea and what does it do?
Avascular, transparent structure that allows light to enter the eyes
Fun fact - it was the first organ transplant since it’s avascular
Cornea injuries can make the cornea become opaque and light can’t pass through
What is the choroid and what does it do?
It’s a thin membrane inside the vascular tunic
IRis
the colored part of the eye
Pupil
Where light enters the eye
What are the two intrinsic eye muscles?
Sphincter pupillae
Dilator pupillae
These are smooth muscles that regular the amount of light going in to the eye
What are the 3 chambers of the eye?
Anterior Chamber
Posterior Chamber
Vitreous Chamber
Anterior chamber location
Between cornea and iris
Posterior chamber location
between iris and lense
Vitreos chamber location
Surrounded by Retina
What is the Aqueous Humor and what does it do?
Ther Fluid that fills the anterior and posterior chamber.
Maintains pressure to keep eye inflated
- refracts light
provides nutrition for structures in the anterior chamber
Scelral venous sinus
The structure that circulates aqueous humor
How does a person get glaucoma?
Lack of aqueous humor circulation
Lens
An odd biological structure that is transparent and biconvex with Crystalline proteins and covered by a capsule
Which Tunic is the retina located in the eye?
The nervous tunic
What is the macula?
The small yellow spot in the retina
What si the Fovea centralis and what does it do?
It’s in the center of the macula. It is where light is most focused when looking at an object
Optic disk
A light spot in the retina where there are lots of blood vessels and where the optic nerve exits the eye
Contains no photoreceptors, and so it is known as the blind spot of the eye.
What are 3 conditions you can diagnose with an ophthalmoscope?
Hypertension
Papilledema (increased CSF - cerebrospinal fluid)
Cataracts
Ciliary Muscles
smooth muscles that control the shape of the lens
Ciliary Process
Responsible for circulation of aqueous humor