Skull anatomy

Question 1

What are the two groups of bones that comprise the skull?

Answer 1

Bones of the cranium and bones of the face

Question 2

What is the vault?

Answer 2

Upper cranium

Question 3

What is the upper cranium called?

Answer 3

Vault

Question 4

What is the floor?

Answer 4

Lower cranium/base of skull

Question 5

What is the lower cranium/base of skull called?

Answer 5

Floor

Question 6

Describe the structure of the bones of the skull?

Answer 6

External and internal tables of compact bone

Separated by a layer of spongy bone (ploie)

Question 7

What is the ploie?

Answer 7

Layer of spongy bone that separates the internal and external tables of skull bones

Question 8

List the three major sutures of the skull?

Answer 8

Coronal suture
Sagittal suture
Lambdoid suture

Question 9

Where does the coronal suture run?

Answer 9

Anterior of two sutures in coronal plane

Articulation between frontal and parietal bones

Question 10

Where does the sagittal suture run?

Answer 10

In the sagittal plane, between the left and right parietal bones

Question 11

Where does the lambdoid suture run?

Answer 11

Posterior of sutures in coronal plane

Articulation between parietal and occipital bones

Question 12

Describe the mobility of sutures?

Answer 12

They are immobile joints

Question 13

What is the point where the coronal and sagittal sutures meet called?

Answer 13

Bregma

Question 14

What is the point where the sagittal and lambdoid sutures meet called?

Answer 14

Lambda

Question 15

What is the pterion?

Answer 15

H shaped suture formation on lateral aspect of skull where the frontal, parietal, temporal and sphenoid bones meet

Question 16

Why can a fracture at the pterion be dangerous?

Answer 16

Thin bones at the pterion
Fracture easily
Middle meningeal artery lies here - sharp spike of bone can tear artery

Question 17

What are the two parts of the frontal bone?

Answer 17

Vertical and horizontal

Question 18

What facial structure does the vertical part of the frontal bone correspond to?

Answer 18

Forehead

Question 19

What structure does the horizontal part of the frontal bone contribute to?

Answer 19

Rooves of orbits

Question 20

What is the line of demarcation between the vertical and horizontal parts of the frontal bone called?

Answer 20

Supra-orbital margins

Question 21

What is the supra-orbital margin?

Answer 21

Line of demarcation between the horizontal and vertical parts of the frontal bone

Question 22

Describe the shape of the parietal bone?

Answer 22

Flat and rectangular

Moulded to brain shape

Question 23

Describe the shape of the occipital bone?

Answer 23

Flat

Moulded to the posterior aspect of the brain

Question 24

What is the extra feature on the occipital bone?

Answer 24

External occipital protuberance

Question 25

List the components of the temporal bone?

Answer 25

``` Squamous part Zygomatic process Mastoid process Styloid process Petrous part ```

Question 26

What is the forward projection of the temporal bone?

Answer 26

Zygomatic process

Question 27

Describe the zygomatic process of the temporal bone?

Answer 27

Projection that passes forward to articulate with zygoma

Question 28

What is the posterior projection of the temporal bone?

Answer 28

Mastoid process

Question 29

Describe the mastoid process of the temporal bone?

Answer 29

Posterior projection that is full of air cells

Question 30

What is the inferior projection of the temporal bone?

Answer 30

Styloid process

Question 31

Describe the styloid process of the temporal bone?

Answer 31

Deep, sharp, inferior projection

Question 32

What is the internal projection of the temporal bone?

Answer 32

Petrous part of temporal bone

Question 33

Describe the petrous part of the temporal bone?

Answer 33

Wedge shaped projection | Projects inward into cranium

Question 34

When can the sphenoid bone be seen fully?

Answer 34

When looking at the cranial base from above

Question 35

List the components of the sphenoid bone?

Answer 35

Body Greater wing Lesser wing

Question 36

What divides the greater and lesser wings of the sphenoid bone?

Answer 36

Superior orbital fissure

Question 37

What is the sella turcica?

Answer 37

'Turkish saddle' | Depression in body of sphenoid where pituitary gland sits

Question 38

Describe the size and position of the greater and lesser wings of the sphenoid bone?

Answer 38

Greater - large, posteroinferior | Lesser- small, anterosuperior

Question 39

Where does the pituitary gland sit?

Answer 39

In the body of sphenoid

Question 40

Where does the ethmoid bone sit?

Answer 40

Between eyes | within frontal bone

Question 41

What facial structures does the ethmoid bone contribute to?

Answer 41

Orbit | Nose

Question 42

Which part of the ethmoid bone can be seen in the cranium?

Answer 42

Cribiform plate

Question 43

What runs through the cribiform plate?

Answer 43

Olfactory nerves

Question 44

What is the crista galli?

Answer 44

Vertical plate of bone that sits up between cribiform plates

Question 45

Describe the initial pathway of the cranial nerves?

Answer 45

Emerge from inferior aspect of brain and exit through foraminae in cranium

Question 46

What are the three fossae in the cranial floor?

Answer 46

Anterior cranial fossa Middle cranial fossa Posterior cranial fossa

Question 47

Which part of the brain does the anterior cranial fossa come into contact with?

Answer 47

Supports frontal lobes

Question 48

Which bones make up the anterior cranial fossa?

Answer 48

Horizontal plates of frontal bone with intervening cribiform plate of ethmoid Lesser wings of sphenoid

Question 49

Which part of the brain does the middle cranial fossa come into contact with?

Answer 49

Supports temporal lobes

Question 50

Which bones make up the middle cranial fossa?

Answer 50

Body and greater wings of sphenoid | Petrous part of temporal bone

Question 51

Which part of the brain does the posterior cranial fossa come into contact with?

Answer 51

Supports occipital lobes and cerebellum

Question 52

Which bones make up the posterior cranial fossa?

Answer 52

Largely occipital bone

Question 53

Which foraminae lie in the anterior cranial fossa?

Answer 53

Cribiform plate

Question 54

Which foraminae lie in the middle cranial fossa?

Answer 54

``` Optic canal Superoir orbital fissure Foramen rotundum Foramen ovale Foramen spinosum (Foramen lacerum) ```

Question 55

Which foraminae lie in the posterior cranial fossa?

Answer 55

Internal auditory meatus Jugular foramen Hypoglossal canal Foramen magnum

Question 56

Which cranial foraminae communicate with the orbit?

Answer 56

Optic canal | Superior orbital fissure

Question 57

Where does the optic canal lie?

Answer 57

In anterior cranial fossa, between body of sphenoid and lesser wing