Untitled Quiz

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Where are the anterior ethmoid foramina located in relation to the anterior lacrimal crest?

Approximately 36 mm posterior
Approximately 12 mm posterior
Approximately 24 mm posterior (correct)
Approximately 42 mm posterior

What is the minimum distance between the posterior ethmoidal artery and the optic nerve?

3 mm (correct)
2 mm
1 mm
4 mm

What surgical technique may be prudent to perform in some cases during a coronal approach?

Elevation of the temporalis muscle
Infraorbital dissection
Direct elevation of the skin
Subperiosteal elevation of the flap (correct)

How far posterior is the posterior ethmoid foramen located compared to the anterior lacrimal crest?

Approximately 36 mm posterior (B) Signup and view all the answers

Which plane is commonly used for dissection during the elevation of the flap in a coronal approach?

Subgaleal plane (A) Signup and view all the answers

Why should an incision be avoided along the inferior orbital rim?

It creates a conspicuous scar. (B) Signup and view all the answers

During incision line design for males with balding patterns, where might the incision be placed?

Several centimeters behind the hairline (B) Signup and view all the answers

What is the recommended extension of the incision if more inferior exposure is needed?

Into a crow's foot wrinkle at least 6 mm above the lateral canthus. (A) Signup and view all the answers

Which of the following structures is NOT located near the optic foramen?

Zygomatic arch (A) Signup and view all the answers

What is the next step after undermining in the supraperiosteal plane?

Another incision through the periosteum. (A) Signup and view all the answers

What anatomical structure is located approximately 42 mm posterior to the anterior lacrimal crest?

Optic canal (D) Signup and view all the answers

Which instruments are predominantly used for subperiosteal dissection?

Two sharp periosteal elevators. (C) Signup and view all the answers

What is a primary advantage of using the stepped incision technique in eyelid surgery?

It assists in maintaining eyelid position. (A) Signup and view all the answers

What is the final step in the incision process after exposing the lateral orbital rim?

Closure in two layers: the periosteum and the skin. (A) Signup and view all the answers

Which approach is known for creating an inconspicuous scar in upper eyelid surgery?

Supratarsal fold approach. (C) Signup and view all the answers

Which method can help protect the cornea during surgical procedures around the orbit?

Inserting a scleral shell. (C) Signup and view all the answers

What composes the distinct layers of the upper eyelid?

Skin, orbicularis oculi muscle, orbital septum, Müller's muscle, and conjunctiva. (C) Signup and view all the answers

When marking the incision line for lower eyelid surgery, what should be taken into account?

The natural direction of skin creases. (A) Signup and view all the answers

What happens if the incision deviates from the original skin crease during lower lid surgery?

It leads to a more noticeable scar. (D) Signup and view all the answers

What happens if one remains in the subperiosteal space during surgery?

Damage to surrounding structures is unlikely. (B) Signup and view all the answers

What is the typical placement for a subciliary incision?

Approximately 2 mm below the eyelashes. (A) Signup and view all the answers

What is the purpose of a tarsorrhaphy suture during eyelid surgery?

To serve as a traction suture for dissection. (A) Signup and view all the answers

What is a disadvantage of the transconjunctival approach?

It cannot access the medial third of the orbital rim. (B) Signup and view all the answers

What could occur if one operates on edematous tissues around the orbit?

Increased risk of ocular damage. (B) Signup and view all the answers

What structure is incised during the transconjunctival approach?

Capsulopalpebral fascia (D) Signup and view all the answers

What is the primary function of the palpebral portions of the orbicularis oculi muscle?

To close the eye without effort, as in blinking (B) Signup and view all the answers

In eyelid surgery, why is it important to avoid curving the incision superiorly as it extends laterally?

It can increase scarring. (D) Signup and view all the answers

Where does the common lateral canthal tendon insert?

About 7 mm from the lateral orbital tubercle (C) Signup and view all the answers

How much does the lower lid descend during full downward gaze?

Approximately 2 mm (D) Signup and view all the answers

What is the purpose of placing a corneal shield during surgery?

To protect the globe from injury (A) Signup and view all the answers

What structure does the orbital septum extend from?

The periosteum of the bones of the face and orbit (A) Signup and view all the answers

From which side does the orbicularis oculi muscle receive innervation?

Lateral side from branches of the facial nerve (A) Signup and view all the answers

Which step involves the injection of a vasoconstrictor?

Step 2: Vasoconstriction (C) Signup and view all the answers

What is the function of the inferior rectus muscle concerning the lower eyelid?

It retracts the lower eyelid during gaze. (C) Signup and view all the answers

What is a characteristic feature of the orbital septum's structure?

It varies considerably in thickness among individuals (B) Signup and view all the answers

What aids in the correct placement of the corneal shield during surgery?

Traction sutures (D) Signup and view all the answers

What is the marginal arcade in relation to the orbicularis oculi muscle?

A blood supply from arterial branches of the ophthalmic artery (B) Signup and view all the answers

Which anatomical structure does the medial canthal tendon insert onto?

Nasal bones and anterior crest (D) Signup and view all the answers

Which of the following structures is NOT involved in the transconjunctival approach?

Medial canthus (C) Signup and view all the answers

What is the relative thickness of the orbital septum laterally compared to medially?

Thicker laterally than medially (A) Signup and view all the answers

What is the primary structural role of the tarsal plate in the lower eyelid?

It gives form and support to the lower eyelid. (C) Signup and view all the answers

How does the size of the inferior tarsus compare to the superior tarsus?

The inferior tarsus is considerably smaller. (A) Signup and view all the answers

Where are the tarsal glands located within the eyelid structure?

Between layers of fibrocartilage. (A) Signup and view all the answers

What is the function of the lateral canthal tendon?

To connect the tarsal plates of the upper and lower eyelids. (C) Signup and view all the answers

Which of the following statements about the Meibomian glands is true?

They produce sebum and are located within the tarsal plates. (D) Signup and view all the answers

What characteristic distinguishes the palpebral conjunctiva?

It lines the inner surface of the eyelids. (A) Signup and view all the answers

What does the grayish line between the lashes and the openings of the tarsal glands indicate?

The junction of skin and muscle with the tarsus. (B) Signup and view all the answers

What shape does the inferior border of the tarsus take?

Semilunar (C) Signup and view all the answers

Pretarsal Muscles

Muscles situated in front of the tarsal plates, contributing to the lateral canthal tendon.

Medial Canthal Tendon

A tendon formed by the union of muscles that inserts on the medial orbital margin, anterior crest, and nasal bones.

Orbicularis Oculi Palpebral Portion

Part of the orbicularis oculi muscle responsible for closing the eye (blinking) and maintaining lid-globe contact.