Ocular Adnexa

Question 1

What could be the pathological consequences of changes in lid position?

Answer 1

• diplopia

- ptosis

Question 2

What is the function of the orbital septum?

Answer 2

Retains orbital contents eg fat, blood vessels, nerves

Question 3

What is the difference between pre septal and post septal (orbital) cellulitis?

Answer 3

Pre septal = bacterial infection of tissues lying anterior to orbital septum
Post septal = bacterial infection of tissues lying posterior to the orbital septum (w/in orbit)

Question 4

What is the function of the superior tarsal muscle? What are the clinical consequences of an interruption to its nerve supply?

Answer 4

• helps to raise the upper eyelid - smooth muscle

- consequence = drooping eyelid (partial ptosis)

Question 5

What is the function of the secretion of the Meibomian glands?

Answer 5

sebaceous gland - releases oil, preventing evaporation of tears

Question 6

What are the internal and external hordeolum?

Answer 6

Internal = infection of meibomian glands 
External = infection of zeis and moll glands

Question 7

What is the function of goblet cells secretion?

Answer 7

produce part of the tear film, produce mucous

Question 8

What is the contribution of the palpebral conjunctiva to the oxygenation of the cornea during sleep?

Answer 8

When sleeping, oxygen and nutrients diffuse from palpebral conjunctival capillaries through the tear film to your cornea - blood vessels in palpebral conjunctiva more permeable

Question 9

What is the relationship between the levator aponeurosis and the lacrimal gland?

Answer 9

Levator aponeurosis divides lacrimal gland into orbital and palpebral lobes

Question 10

How do acini differ from ducts?

Answer 10

• contain only serous cells and produce a watery serous secretion
• ducts are vertically orientated with respect to the lid margins with multiple secretory acini, opening laterally onto each duct

Question 11

What is the function of myoepithelial cells?

Answer 11

-involved in the release of tears, have contractile properties that squeeze tears out?

Question 12

How do the eyelids protect the eye?

Answer 12

• Protect the eye against excessive light and by their reflex closure confers protection against injury
• Action of blinking is critical for the formation and recycling of the pre ocular tear film

Question 13

Which 2 muscles move the eyelids during the blinking process?

Answer 13

Obicularis oculi and levator palpebrae superioris

Question 14

What are the 3 principal glands of the eyelid?

Answer 14

Tarsal (meibomian) glands - embedded in dense connective tissue in the tarsal plates
Glands of Zeis (ciliary sebaceous glands)
Glands of Moll (ciliary sweat glands)
Latter glands are closely associated with the ciliary (eyelash) zone

Question 15

What is the conjunctiva?

Answer 15

Transparent mucus membrane that lines the eyelids and covers the exposed parts of the sclera. It forms a sac which opens the eyelid margins

Question 16

What are the 5 regions the conjunctiva can be divided into?

Answer 16

Margibal, Tarsal, orbital, bulbar and limbal

Question 17

What is the fornix of the conjunctiva?

Answer 17

Represents the point at which the conjunctiva folds and is reflected onto the globe

Question 18

What makes up the lacrimal system?

Answer 18

Main and accessory lacrimal glands and the lacrimal drainage system

Question 19

Where is the main lacrimal gland located?

Answer 19

Located in a fossa withing the frontal bone in the upper lateral quadrant of the orbit

Question 20

Where are the accessory lacrimal glands located?

Answer 20

-small collections of lacrimal tissue which are found in the stroma of the orbital conjunctiva