Topic 1: Anatomical planes & the Orbit

Question 1

what are the three anatomical planes?

Answer 1

Sagittal: vertical plane divides into left and right (medial and lateral) (half)

Coronal: vertical dividing the structure into anterior front and back posterior parts

horizontal plane: dividing the structure into top and bottom parts

Question 2

which plane divides the eyeball into similar sections?

Answer 2

horizontal and sagittal

Question 3

what are the 7 bones that make up the orbit?

Answer 3

1) Frontal
2) Sphenoid
3) Ethmoid
4) Zygomatic
5) Maxillary
6) Palatine
7) Lacrimal

Question 4

what is the orbit and what is its main function?

Answer 4

The orbit is a socket that the eye sits in.

Its main function would be to protect the eye from injury.

Question 5

what 2 bones does the superior wall contain

Answer 5

Mainly frontal bone and a small part of the sphenoid.

contains optic foramen!

Question 6

what 2 bones does the Lateral Wall contain? what is one property of this wall?

Answer 6

Thickest wall!!

Consists mainly of the Zygomatic and the greater wing of the sphenoid.

Question 7

what 4 bones does the medial Wall contain? what is one property of this wall?

Answer 7

Very thin wall that consists of the maxilla, lacrimal, ethmoidal and a small part of the lesser wing of sphenoid.

Question 8

what 3 bones does the inferior Wall contain? what is one property of this wall?

Answer 8

• The thinnest wall that consists of the maxilla, palatine and part of the zygomatic.

Question 9

what wall does blow out fracture affect? what happens in a blow out fracture?

Answer 9

inferior wall. Due to a blunt trauma, the inferior wall gives way and the orbital contents “fall down” into the cavity aka sinus

Question 10

what are the 2 functions of the orbital fasciae

Answer 10

Line & support the structures within the orbit.

Allow for easy rotation

Question 11

what are the 3 types of orbital fasciae u gotta know

Answer 11

Periorbita
Orbital septum
Bulbar Fascia (tenon’s capsule)

Question 12

what is the periorbita? what is its function?

Answer 12

layer of tissue surrounding the orbit. lines inner wall of orbit

Question 13

what is the orbital septum? what is its function?

Answer 13

located behind lids and acts as anterior boundary of the orbit. holds the eyeball in place

Question 14

what is the tenon’s capsule? what is its function?

Answer 14

It is a thin membrane that covers the sclera **but does not cover the cornea and optic nerve region

Question 15

what are sinuses? what are its functions?

Answer 15

they are hollow cavities that are filled with air in the skull.

they act as resonators for our voice to travel and reduce the weight of the skull

Question 16

what are the three things to know about the optic foramen?

Answer 16

1. the optic nerve exits here
2. opthalmic artery that supplies eyeball with blood and nutrients enters here
3. the annulus of zinn, which is the origin of the 4 recti eye muscles, is located right in front of the optic foramen