L1 Anatomical Planes And The Orbit

Question 1

what are the 3 anatomical planes?

Answer 1

1. sagittal
2. coronal (frontal)
3. transverse (horizontal)

Question 2

what is the sagittal plane?

Answer 2

• divides the eye into right/medial (closer to nose) and left/lateral (away from nose) parts
• vertical plane running from the anterior to posterior

Question 3

What is the coronal (frontal) plane?

Answer 3

• divides The Eye into anterior (front) and posterior (back) parts
• vertical plane from side to side

Question 4

What is the transverse (horizontal) plane?

Answer 4

• horizontal plane dividing the structure into superior (upper) and inferior (lower) parts

Question 5

What is the orbit made up of:

Answer 5

• made up of 7 bones
  1. Frontal
  2. Sphenoid
  3. Ethmoid
  4. Zygomatic
  5. Maxillary
  6. Palatine
  7. Lacrimal

Question 6

What are the 4 walls of the orbit?

Answer 6

1. Orbital roof
2. Medial wall
3. Inferior wall/orbit wall
4. Lateral wall

Question 7

What is the orbital roof?

Answer 7

• > made up of: (FS)
• frontal bone
• sphenoid bone

Question 8

What is the medial wall?

Answer 8

• > thinnest
• > made up of: (MLES)
• maxillary bone
• lacriminal bone
• ethnoid bone
• sphenoid bone

Question 9

What is the inferior wall/orbit wall? (MPZ)

Answer 9

-> weakest + thinnest

• > made up of:
• maxillary bone
• palatine bone
• zygomatic bone

Question 10

What is the lateral wall?

Answer 10

• > made up of: (SZ)
• sphenoid bone
• zygomatic bone

Question 11

What is the optic canal/optic foremen?

Answer 11

1. Optic nerve exits the eyeball from the optic foremen
2. Ophthalmic artery enters the eyeball through the optic foremen
3. The annulus of zinc, the origin of the 4 recti muscles, is right infront of the optic foremen
   (The 4 recti muscles are superior rectus, inferior rectus, medial rectus, lateral rectus

Question 12

What is the orbital fasciae?

Answer 12

-> consists of sheets of connective tissue that line and support the structures within the orbit

• > functions:
  1. Line and support the structures within the orbit
  2. Allows for easy eye rotation
• > 3 important parts of the fasciae
  1. Periorbita
  2. Orbital septum
  3. Bulbar fascia

Question 13

What is the periorbita

Answer 13

The layer of tissue surrounding the orbital walls

Question 14

What is the orbital septum

Answer 14

-> it is a membranous sheet that acts as the anterior boundary of the orbit

• > prevents the eyeball from dropping out
• prevents facial infections from entering the orbit
• rmb that orbital septum is a tissue, not a bone

Question 15

What is the fascia bulbi / tenon’s capsule/ bulbar sheath?

Answer 15

• a thin membrane that lines the eyeball

- > it covers the entire eye except at the cornea and optic nerve