Orbit Bones (M1)

Question 1

2 parts of the skull

Answer 1

1. cranium
2. face

Question 2

where do bones meet

Answer 2

sutures

Question 3

define sinuses

Answer 3

air-filled cavities within bones

Question 4

what does the frontal bone form

Answer 4

anterior portion of the cranium, anterior floor, and superior part of the face

Question 5

what does parietal bone form

Answer 5

roof and lateral sides (right and left)

Question 6

what does temporal bone form

Answer 6

floor and lateral sides (right and left)
ears!

Question 7

what does occipital bone form

Answer 7

posterior portion of the cranium and posterior floor.
foramen magnum found!
doesn’t contribute to orbit

Question 8

what does the sphenoid bone form

Answer 8

floor

Question 9

3 portions of sphenoid bone

Answer 9

body of sphenoid:
- houses pituitary gland in a depression called sella turcica
lesser wings of sphenoid:
- project from anterior aspect of body
greater wings of sphenoid:
- project from lateral aspect of body

Question 10

4 parts of ethmoid bone

Answer 10

vertical (perpendicular) plate:
- forms nasal septum
horizontal (cribiform) plate:
- olfactory nerves pass through the plate
labyrinths (x2):
- house ethmoidal sinuses

Question 11

what are the bones of the face and what do they form

Answer 11

1. frontal bone: forehead and orbital roof
2. palatine bone: extends from hard palate at back of mouth to orbital floor
3. lacrimal bone: medial wall of orbit
4. nasal bone: bridge of nose
5. inferior conchae: lateral wall of nasal cavity
6. vomer: posterior part of nasal septum
7. zygomatic bone: lateral part of cheekbone and lateral wall and floor of orbit
8. maxillary bone: upper jaw, cheek, hard palate, lateral wall of nasal cavity, floor of orbit
9. mandible: movable lower jaw

Question 12

what does the orbit contain

Answer 12

globe, connective tissue, extraocular muscles, orbital nerves, blood vessels, and fat

Question 13

what is the orbit shaped like

Answer 13

4-sided pyramid w apex posteriorly and base anteriorly.
apex is most posterior portion of orbit and located slightly nasal

Question 14

what bones form the orbit

Answer 14

1. frontal
2. palatine
3. lacrimal
4. zygomatic
5. maxillary
6. sphenoid
7. ethmoid

Question 15

what is the roof formed by

Answer 15

frontal and sphenoid (lesser wing) bones.
majority is frontal bone

Question 16

what is the floor formed by

Answer 16

palatine, zygomatic, and maxillary bones

Question 17

what is the weakest wall in orbit

Answer 17

floor
- groove/canal in maxillary bone
- air-filled sinus beneath floor

Question 18

what is the medial wall formed by

Answer 18

ethmoid, maxillary, lacrimal, and sphenoid (body) bones.
majority is ethmoid bone

Question 19

what is the thinnest wall in orbit

Answer 19

ethmoid

Question 20

what is the lateral wall formed by

Answer 20

zygomatic and sphenoid (greater wing) bones

Question 21

what is the strongest area in the orbit

Answer 21

lateral orbital rim (margin).
most exposed to possible injury

Question 22

what is the purpose of the paranasal sinuses

Answer 22

reduce weight of skull and filter the air we breathe

Question 23

what are the paranasal sinuses

Answer 23

maxillary: inferior to orbits; largest.
sphenoid: posterior and medial to orbits.
ethmoid: medial to orbits.
frontal: superior to orbits

Question 24

sinusitis

Answer 24

air cavities become infected.
infection can spread through thin sinus cavity walls to orbit