Foramina, fissures, and fossa

Question 1

Foramen (pl: foramina)

Answer 1

Hole or opening in bone

• allows the entrance and exit of nerves/vessels in and out of the orbit.
• Optic foramen/canal, supraorbital foramen (hole in frontal bone), supratrochlear foramen, infraorbital foramen (hole in maxillary bone)

Question 2

Fissure

Answer 2

Long, narrow opening in bone
Allows entrance and exit of nerves and vessels in and out of the orbit
Superior orbital fissure, inferior orbital fissure (in maxillary bone on floor)

Question 3

Fossa

Answer 3

Shallow depression in bone.
Anatomical structures are positioned in fossa.
Lacrimal fossax2

Question 4

Foramen that lies between the lesser wing and body of the sphenoid

Answer 4

Optic foramen (optic canal)

Question 5

Where is the optic canal/foramen located

Answer 5

Lies between the lesser wing and body of sphenoid
At the orbital apex (posterior), slightly nasal
Opening between the orbit and cranial cavity.

Question 6

Tendinous ring or annulus of zinn

Answer 6

Lies anterior to the optic canal. Lies anterior to the INFERIOR part of the supraorbital fissure. Band of connective tissue that is the origin for four of the extra ocular muscles.

Question 7

What passes through the optic canal and annulus of zinn

Answer 7

CN 2 and the ophthalmic ARTERY

Question 8

Where does the superior orbital fissure (supraorbital fissure) lie

Answer 8

Lies between the greater and lesser wings of the sphenoid. It is in the inferior part of the the apex (slightly nasal and posterior).

Question 9

Nerves that pass through the inferior part of the superior orbital fissure and THROUGH the annulus of Zinn

Answer 9

Superior and inferior division of the oculomotor nerve (CN III), nasociliary nerve (CN V1) and the abducens nerve (CNV1)

Superior to inferior- S.A.N.I
S uperior branch of oculomotor nerve III
A bducens nerve (VI AKA 6)
N asociliary nerve (CN V1)
I inferior branch of oculomotor nerve III

Question 10

Three divisions of the trigeminal (CN V AKA 5) nerve

Answer 10

V1- Ophthalmic 
- Frontal nerve (supraorbital and supratrochlear nerves that exit through the supraorbital notch/foramen and supratrochlear notch/foramen) 
-Lacrimal nerve
-Nasociliary nerve
V2- Maxillary 
- Zygomatic nerve
- Infraorbital nerve, artery, and vein
V3- Mandibular

Question 11

Nerves and vessels that pass through the superior orbital fissure and ABOVE the annulus of zinn.

Answer 11

(Superior to inferior)

Lacrimal Nerve (CN V1) 
Frontal nerve (CN V1)  
Trochlear nerve (CN IV AKA 4) 
Superior ophthalmic VEIN

Question 12

common tendinous ring is __ to the optic canal and ___ to the superior orbital fissure

Answer 12

Anterior to the optic canal and anterior to the inferior portion of the superior orbital fissure.

Question 13

__

C

Answer 13

With

Question 14

Where is the inferior orbital fissure (infraorbital fissure) located and what passes through it

Answer 14

Lies between the floor of the orbit and the lateral wall. Inferior to the tendinous ring. Nerves and vessels pass through including the:

Inferior ophthalmic VEIN
Zygomatic nerve (CN V2)
Infraorbital nerve (CN V2) artery and vein. 

V2= apart of the maxillary division of the trigeminal nerve (nerve #5)

Question 15

Where do nerves and vessels pass through after exiting the infraorbital fissure

Answer 15

Continue through the infraorbital groove/canal and out the infraorbital foramen

Question 16

Lacrimal fossa

Answer 16

Depends on what lacrimal structure you are looking for. There are 2 lacrimal fossa.

1 located in the temporal portion of the frontal bone. Holds the lacrimal GLAND.

The other is located medially, separated from the orbit by the orbital septum (anterior and medial to the orbit) an is where the lacrimal sac sits.

Question 17

Where does the lacrimal gland sit

Answer 17

In the lacrimal fossa, which is located in in the temporal portion of the frontal bone.

Question 18

Where does the lacrimal sac sit

Answer 18

The lacrimal sac sits in the lacrimal fossa that is located medially and anterior to the orbit. This lacrimal fossa and the lacrimal sac are technically not apart of the orbit. This prevents infection from the sac from spreading to the orbit.

Question 19

How does the lacrimal fossa/sac extend into the nasal cavity

Answer 19

The nasolacrimal canal (which holds the nasolacrimal duct) is in the maxillary bone and extends from the fossa to open in the nasal cavity

Question 20

Which bones form the posterior and anterior lacrimal crests of the lacrimal fossa

Answer 20

The lacrimal bone forms the posterior crest and the frontal process of the maxillary bone forms the anterior crest. This is where the lacrimal sac will sit, outside of the orbit

Question 21

How is the lacrimal sac and fossa separated from the orbit

Answer 21

It is separated medially and anteriorly by the orbital septum, which is a sheet of dense connective tissue. Prevents disease from spreading.

Question 22

Another word for sulcus

Answer 22

Fossa

Question 23

Another word for fossa

Answer 23

Sulcus

Question 24

What are the 2 foramens/notches located superior to the orbit

Answer 24

Supraorbital foramen/notch and more medially, the supratrochlear foramen/notch. Both are openings between the orbit and facial surface.

Question 25

What passes through the supraorbital foramen/notch

Answer 25

Supraorbital nerve (CN V1), artery and vein pass through

This nerve is apart of the ophthalmic division and considered a frontal nerve.

Question 26

What passes through the supratrochlear foramen/notch

Answer 26

Supratrochlear nerve (CN V1) artery and vein pass through.

This nerve is apart of the ophthalmic division and considered a frontal nerve.

Question 27

What passes through the infraorbital foramen

Answer 27

Infraorbital nerve (CN V2) artery and vein. Pass through the inferior orbital fissure, then down the infraorbital groove and out through the infraorbital foramen.