Unit Three: Visual System Flashcards
What are the two functions of eyebrows?
- Prevent sweat from dripping into the eye. 2. Shade the eyes from sunlight.
What is the function of eyelashes?
Prevent large foreign objects from contacting the eyes.
Are eyelashes highly innervated?
Yes.
What are eyelids also known as?
Palpebrae.
What is the palpebral fissure?
The opening between the eyelids.
What are tarsal plates and what do they do?
Connective tissue. They help create the structure of the lid and provide attachment for the orbicularis oculi.
What are tarsal glands a modification of?
Modified sebaceous glands.
What are the functions of the tarsal glands? (3)
- Lubricates surface of the eye. 2. Prevent tears from going over the surface of the eye. 3. Prevents eyes from sticking together.
What does the palpebral line?
The eyelid.
What does the bulbar line?
The eye.
What is the conjunctiva?
A transparent mucous membrane made of stratified squamous epithelium.
What are the two segments of the conjuctiva?
- Palpebral. 2. Bulbar.
What kind of cells do conjuctiva contain and what do they do?
Goblet cells that lubricate the surface of the eye.
What is the function of the lacrimal apparatus? (2)
- Produces, collects, and drains lacrimal fluid (tears from the eye. 2. Helps prevent bacterial infections using an antibiotic-like enzyme called lysozyme.
What are the first two initial steps of the tear pathway?
- Lacrimal fluid is produced in the lacrimal gland. 2. Lacrimal fluid is dispersed across the eye surface when blinking.
What happens after lacrimal fluid is dispersed across the surface of the eye? (3) (The final 3 steps of the tear pathway.)
- Lacrimal fluid is drained into lacrimal canaliculi via the lacrimal puncta and collects in the lacrimal sac. 2. Lacrimal fluid drains through the nasolacrimal duct. 3. Enters the nasal cavity.
What nerve causes the production of lacrimal fluid? What kind of innervation is it?
Cranial nerve VII. Parasympathetic.
What is the action of the lateral rectus?
Abduct eye laterally.
What nerve innervates the lateral rectus?
CN VI (Abducens nerve).
What is the action of the medial rectus?
Abduct eye medially.
What is the action of the inferior rectus?
Depress eye.
What is the action of the superior rectus?
Elevate eye.
What is the action of the inferior oblique?
Elevates and abducts eye.
What is the action of the superior oblique?
Depress and abducts eye.