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Flashcards in Anatomy of the Orbit Deck (81)
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1

How many bones make up the orbit of the eye?

7

2

Which bones make up the orbit of the eye?

  1. Frontal
  2. Zygomatic
  3. Maxilla
  4. Nasal
  5. Sphenoid
  6. Ethmoid
  7. Lacrimal

3

Which aspect of the frontal bone allows passage of the supraorbital nerve?

Supraorbital notch

4

Which bone contains the optic canal?

Sphenoid bone

5

The optic canal is the _____ of the bony orbit

The optic canal is the apex of the bony orbit

6

What is the main function of the optic rim?

Protects the eye from direct trauma

7

Which bones mainly comprise the following regions of the bony orbit?

a) Roof

b) Medial wall

c) Lateral wall

d) Floor

a) Roof - Frontal bone

b) Medial wall - Ethmoid bone

c) Lateral wall - Sphenoid bone

d) Floor - Maxilla

8

Which aspects of the bony orbit are particuarly weak and thin?

  1. Medial wall (ethmoid)
  2. Orbital floor (maxilla)

9

Which type of fractures are the medial wall and floor of the orbit particuarly susceptible to?

Blowout fractures

10

Which main problems arise with an orbital blowout fracture?

  1. Trapped orbital contents
  2. Infraorbital NVB damage
  3. Sensory deficit of facial skin

11

Which areas does the infraorbital nerve innervate?

  1. Ala of nose
  2. Skin around maxilla (lower eyelid to upper lip)

12

Why may a fractured zygoma result in double vision?

  1. Fractured zygoma rotates medially
  2. Suspensory ligament attaches to zygoma laterally
  3. Eye lowered to orbital floor as tension reduced
  4. Diplopia occurs

13

What is the name given to the muscle surrounding the orbit of the eye?

Orbicularis oculi

14

The orbicularis oculi is split into which two parts?

  1. Orbital part
  2. Palpebral part

15

Which type of secretion do the tarsal (eyelid) glands secrete?

Lipid secretion

16

What is the orbital septum and what is its function?

Sheet of fascia

Aids in preventing spread of infection

17

What is the name of the muscle(s) which elevates the upper eyelid?

  1. Levator palpebrae superioris
  2. Superior tarsal (Müller's*) muscle

*Do not confuse with orbitalis muscle (also known as Müller's muscle)

18

Which muscle is primarily responsible for:

a) Gently closing eyes

b) Screwing up eyes

a) Orbicularis oculi (palpebral aspect) - Gently closing eyes

b) Orbicularis oculi (orbital aspect) - Screwing up eyes

19

Which cranial nerve innervates the orbicularis oculi?

Facial nerve

(CN VII)

20

Which structure covers the iris?

Cornea

21

What is the limbus?

Corneal/scleral junction

22

Which glands are responsbile for tear production?

Lacrimal

23

Where does lacrimal fluid drain within the eye?

Puncta (inferior and superior)

24

What is the conjunctival fornix?

Loose arching folds connecting the conjunctival membrane lining the inside of the eyelid with the conjunctival membrane covering the eyeball

25

The conjunctiva does not cover which part of the eye?

Cornea

26

What is the pathway of lacrimal fluid drainage?

  1. Lacrimal puncta
  2. Canaliculi
  3. Lacrimal sac
  4. Nasolacrimal duct
  5. Nasal cavity

27

What is the approximate diameter of the eye?

25mm

28

What are the 3 main layers of the eye?

  1. Fbrous layer
  2. Vascular layer (uvea)
  3. Inner layer (retina)

29

The fibrous layer of the eye is comprised of which two main components?

  1. Sclera
  2. Cornea

30

The vascular layer (uvea) of the eye is comprised of which 3 parts?

  1. Iris
  2. Ciliary body
  3. Choroid