All bones of the Skull with the surface markings

Question 1

What are the Parts of the Frontal bone?

Answer 1

Parts of bone:
Frontal Squama, Supraorbital Notch, Supraorbital Foramina, Supraorbital Margin.
What the bone forms:
Forehead, most of the anterior portion of the cranial floor, and the roof of the orbit.
Deep in the frontal squama is the frontal Sinus.
Inferiorly to the frontal bone is the Coronal Suture.

Question 2

What are the parts of the Parietal bones?

Answer 2

Parts of the bone:
It articulates with the Occipital, temporal and frontal bones. This includes Coronal suture, the Squamous suture and the Lambdoid suture.
What it forms:
The parietal bone forms the greater portion of the sides of the cranium.
Inside the Cranial cavity there are many protrusions and depressions that accommodate blood vessel.

Question 3

What is the Zygomatic arch formed by?

Answer 3

The arch is formed by Zygomatic process of the temporal bone and the temporal process of the Zygomatic bone.

Question 4

Where is the Sutural bone located?

Answer 4

It is located posteriorly and inferiorly to the Parietal bones and superior to the Occipital bones.

Question 5

What is is the Zygomatic Process?

Answer 5

The Zygomatic process articulates with the Temporal process of the Zygomatic bone to form the Zygomatic arch.
Inferior- posterior of the Zygomatic arch is the Mandibular Fossa and Anterior to this is the a rounded elevation called the articular tubercle. Together they articulate with the mandible to form the Tempomandibular joint (TMJ).

Question 6

Where is the Mastoid Portion in the Skull?

Answer 6

This is located Posterior-Inferior to the External Auditory Meatus.
In an adult this portion of the bone contains several air cells. middle ear infections that go untreated can spread to the mastoid air cells and cause inflammation called (Mastoiditis).

Question 7

What is contained in the Mastoid Process?

Answer 7

In this portion of the Temporal bone there is a rounded projection called the Mastoid process that is the attachment point for many neck Muscles.

Question 8

Where is the Mandibular Fossa located?

Answer 8

This Surface marking is located in the Inferior-Posterior portion of the Zygomatic process and just posterior to the Articular Tubercle.

Question 9

What Major bones in the Skull are Joined by the Squamous suture, Lambdoid Suture and the Coronal suture?

Answer 9

The Parietal and temporal bones are joined by the Squamous.
Parietal and Occipital bones are joined by the Lambdoidal.
Parietal and Frontal bones are joined by the Coronal.

Question 10

Where is the Styloid Process located?

Answer 10

Located in the most Inferior portion of the Temporal bone it projects Inferiorly.
It serves as an attachment point for muscles and ligaments of the neck tongue.

Question 11

What is the Stylomastoid Foramen?

Answer 11

This is located between the Styloid process and the mastoid process.

Question 12

What does the Petrous portion of the Temporal bone contain?

Answer 12

This portion of the Temporal bone is a Triangular zone located between the Sphenoid and Occipital bone.
It houses internal and middle ear structures it also contains the Carotid Foramen.
Posterior to this is the Jugular Foreman.

Question 13

What does the Occipital Bone contain?

Answer 13

The Foramen Magnum in the Inferior portion of the bone
The External Occipital Protuberance (EOP) along with the Superior and inferior Nuchal lines.
The Occipital Condyles that help create the Atlanto-Occipital Joint.
Hypoglossal Canal

Question 14

What is the EOP used for?

Answer 14

It serves as a point of attachment for the Ligamentum Nuchae.
This extends from the EOP to the C7 vertebra.

Question 15

What are the Occipital Condyles?

Answer 15

Oval Process with Convex Surfaces on ethier side of the Foramen Magnum.
They articulate with Depressions on the C1 and form the Atlanto-Occipital joint.

Question 16

What does the Sphenoid bone contain?

Answer 16

Articulates with all the Cranial bones.
The space inside the Sphenoid body is called the Sphenoid Sinus which drains into the Nasal Cavity.

The Sella Turcica is an important portion of the bone containing Turberculum sellea, Hypophyseal Fossa, Dorsum Sellea.

The Greater and lesser wings lateral to the body.
Anterior to the Sella Turcica is the Optic foreman or canal.
The Superior Orbital fissure, The Pterygoid Process Foreman Oval and Lacerum.
Foreman Rotundum.

Question 17

Where is the Sella Turcica located and what is its purpose?

Answer 17

This is located on the Superior portion of the Sphenoid body and contains 3 parts called:
Terbeculum Sellea
Hypophyseal Fossa
Dorsum Sellea

Question 18

What is the Hypophyseal Fossa used for in the Sphenoid bone?

Answer 18

This is the location of the Pituitary Gland.

Question 19

Where are the Greater Wings of the Sphenoid bone located and what is their purpose?

Answer 19

Projecting Laterally from the Body they form the Anterolateral floor of the Cranium and the lateral wall of the skull just anterior to the Temporal bone.

Question 20

Where are the Lesser wings in the Cranium and what is their purpose?

Answer 20

Anterior-Superior to the Greater Wings:
They form part of the Cranium and posterior part of the Orbit.
And apart of the Sphenoid bone.

Question 21

What is the Foreman located Anterior to the Sella Turcica?

Answer 21

Optic Foreman or Canal.

Question 22

What and where are the Pterygoid Process?

Answer 22

It projects Inferiorly from the point where the Body and the Greater wings unite. They form the Lateral-Posterior region of the Nasal Cavity.

Some of the Muscles that move the Mandible attach at the base of the Lateral Pterygoid process.

Question 23

What is the Triangular Slit lateral to the body of the Sphenoid bone called?

Answer 23

Superior Orbital Fissure may also be seen through the Anterior view on Orbit diagrams.

Question 24

What are all the Foreman of the Sphenoid bone?

Answer 24

Foreman Rodundum, Oval, Spinosum, Lacerum, Optic.

Along with the Optic Fissure.

Question 25

What does the Ethmoid bone contain?

Answer 25

The Cribriform Plate, Crista Galli, Perpendicular plate, lateral mass, Ethmoidal Cells, Superior-medial nasal Conchae.

Question 26

Where is the Ethmoid located?

Answer 26

Anterior to the Sphenoid bone and Posterior to the Nasal bones. Medial to the Orbits.

Question 27

What does the Ethmoid bone form?

Answer 27

Forms the:

1. Part of the Anterior portion of the Cranial floor
2. The Medial wall of the Orbits
3. The Superior portion of the Nasal Septum
4. Most of the Superior side walls of the Nasal Cavity

Question 28

What does the Perpendicular plate form?

Answer 28

Forms the Superior portion of the Nasal septum.

Question 29

Where is the Cribriform plate located and what does it contain?

Answer 29

Located in the Anterior portion of the Cranial cavity it contains Olfactory Foreman and the Crista Galli that projects superiorly creating the attachment point for the membrane that separates the brain into left and right sides.

Question 30

What are the superior, Medial nasal concha and where are they located?

Answer 30

They are located in the inferior portion of the lateral masses of the Ethmoid bone.
The most proximal part is the Superior part and the Distal end of the conchae is the Medial portion.
Inferior to both of the Masses are a pair of Scroll like bones called Inferior Nasal Conchae separate from the Ethmoid bone.