Skull Intro

Question 1

Cranium

Answer 1

The skeleton of the head aka the skull

Question 2

What are the two parts of the cranium?

Answer 2

neurocranium and the viscerocranium

Question 3

Neurocraniuma(description and contents)

Answer 3

The bony covering of the brain and the cranial meninges. Contains proximal part of the crainial nerves and the vasculature of the brain

Question 4

Calvaria

Answer 4

The dome like roof of the neurocranium

Question 5

Cranial base

Answer 5

The floor of the neurocranium

Question 6

Which bones make up the neurocranium and which ones come in pairs?

Answer 6

Frontal, Ethmoid, Sphenoid, Occipital, Temporal(pair), & Parietal(pair)
8 total bones

Question 7

How are the bones of the neurocranium formed?

Answer 7

• Intramembranous ossification of the head mesenchyme from the neural crest
• Endochondral ossification of cartilage(chondrocranium)

Question 8

What do the bones of the viscerocranium surround or comprise?

Answer 8

• The mouth(upper and lower jaw)
• The nose/nasal cavity
• most of the orbits

Question 9

What bones make up the viscerocranium and which come in pairs?

Answer 9

-mandible
-ethmoid
-Vomer
pairs:
-Maxillae
-Inferior nasal conchae
-zygomatic
-palatine
-lacrimal
-nasal

Question 10

How do the bones of the viscerocranium from

Answer 10

Develop in the mesenchyme of the embryonic pharyngeal arches

Question 11

What is considered anatomical position of the skull?

Answer 11

It is when the inferior margin of the orbital and the superior margin of the external acoustic meatus lie in the same horizontal plane.

Question 12

What is the plane that runs horizontally from the inferior margin of the orbit to the superior margin of the external acoustic meatus called?

Answer 12

The orbitometal or Frankfort plane

Question 13

what are the 4 bones visible from an anterior position?

Answer 13

Frontal, the right and left parietal, and the occipital

Question 14

Coronal suture

Answer 14

Separates the frontal bone anteriorly and the parietal bones posteriorly

Question 15

Sagittal suture

Answer 15

Separates the right and left parietal bones

Also called the inter parietal suture

Question 16

Bregma

Answer 16

The intersection of the sagittal and coronal suture

Question 17

Lambdoidal suture

Answer 17

separates the parietal and temporal bones from the occipital bone

Question 18

Lambda

Answer 18

Where the sagittal and lambdoidal suture intersect

Question 19

Frontal eminences(where and what to they signify)

Answer 19

The anterior corners of the forehead

They signify the initial site of ossification of the frontal bone

Question 20

Parietal eminences(where and what to they signify)

Answer 20

the more prominent postereolateral bulges

They signify the initial site of ossification of the parietal bone

Question 21

Describe frontal bone development.

Answer 21

The frontal bone develops from two memebranous ossification centers of the frontal eminences duing the seventh fetal week
At birth the right and left frontal bones are separated by a midline metopic, or interfrontal, suture.
It starts to fuse at age 1 then is obliterated at age 6, there maybe still some remnants left

Question 22

What shape does the zygomatic area form?

Answer 22

An arch

Question 23

What is the keystone of the zygomatic arch?

Answer 23

The zygomatic bone

Question 24

What are the 3 bones supporting the zygomatic arch and their position?

Answer 24

Maxilla, anteriorly
Frontal, superiorly
Temporal, posteriorly

Question 25

Zygomaticofacial foramen

Answer 25

Located centrally on the prominence of the zygomatic bone and transmits the zygomaticofacial vessels and nerve

Question 26

Superior wall of the orbit

Answer 26

Basically horizontal and formed by the orbital part of the frontal bone near the apex of the orbit it is made of the lesser wing of the sphenoid bone

Question 27

median wall of the orbit

Answer 27

primarily made of the ethmoid bone, with parts from the frontal, lacrimal, and palatine bones.

Question 28

inferior wall of the orbit

Answer 28

Formed mainly by the maxilla and partly by the zygomatic and palatine bones

Question 29

Inferior orbital fissure

Answer 29

partly separates the lateral and inferior wall of the orbit

Question 30

lateral wall of the orbit

Answer 30

formed by the frontal process of the zygomatic bone and the greater wing of the sphenoid bone. The lateral walls of the two orbits are perpendicular to each other

Question 31

Supraorbital notch or foramen

Answer 31

located directly above the medial third of the superior margin of the orbit Transmits the supraorbital vessels and nerves

Question 32

Infraorbital foramen

Answer 32

located 7-8mm below the midpoint of the inferior margin of the orbital. Communicates with the infra-orbital canal and groove in the floor of the orbit and transmits the infraorbital vessels and nerve

Question 33

List the apertures of the wall of the orbit.

Answer 33

- Superior orbital fissure - Inferior orbital fissure - Optic canal - Anterior and posterior ethmoidal foramen

Question 34

Structures running through the superior orbital fissure

Answer 34

CN-III,IV,VI,V1

Question 35

Structures running through the inferior orbital fissure

Answer 35

CN-V2 and the infraorbital vessels

Question 36

Structures running through the optic canal

Answer 36

CN-II and the Ophthalmic artery

Question 37

Structures running through the anterior and posterior ethmoidal foramen

Answer 37

Anterior and posterior ethmoid nerve, artery, and veins

Question 38

Bones of the anterior cranial fossa

Answer 38

Frontal, ethmoid and sphenoid bones

Question 39

Bones of the middle cranial fossa

Answer 39

Sphenoid, temporal, and parietal bones

Question 40

Bones of the posterior cranial fossa

Answer 40

Occipital, temporal and parietal bones

Question 41

What do the temporal line signify?

Answer 41

They represent the superior limit of the curved origin of the temporalis muscle

Question 42

Pterion

Answer 42

The H shaped junction of the frontal, greater wing of the sphenoid, parietal and temporalis bones