2) Osteology of the H&N

Question 1

What are the bones that make up the cranium?

Answer 1

Calvaria:
Frontal
Parietal (2)
Occipital
Ethmoid

Cranial base:
Sphenoid
Temporal (2)

Question 2

What do the bones of the calvaria (vault of skull) consist of?

Answer 2

2 layers of compact bone

separated by a layer of bone marrow (Diploe)

Question 3

What do the bones of the cranial base articulate with?

Answer 3

Atlas (C1)
Facial skeletion
Mandible

Question 4

Name the 3 sutures that join the bones of the cranium

Answer 4

Coronal
Sagittal
Lamboidal

Question 5

Name 5 sites the skull is prone to fracture

Answer 5

Foramen magnum
Anterior cranial fossa
Middle cranial fossa (weakest)
Posterior cranial fossa
Squamous temporal bone & inner parts of Sphenoid wing

Question 6

Describe some of the symptoms of skull fractures

Answer 6

Bleeding from wound, ear, nose, around eyes
bruising, draining of CSF from ears/nose
swelling, confusion, convulsions, drowsiness & lots more

Question 7

Name 7 types of skull fracture

Answer 7

Depressed
Linear Calvarial
Comminuted
Contrecoup (counterblow)
Simple
Compound
Basal Skull

Question 8

What is a depressed fracture?

Answer 8

Severe, localised blow
localised indentation
fragment of bone may compress or injure underlying brain

Question 9

What is a linear calvarial fracture?

Answer 9

Trauma to Calvaria

Results in radiating linear fractures away from point of impact in 2 or more directions

Question 10

What is a comminuted fracture?

Answer 10

The bone is broken into several pieces

Question 11

What is a contrecoup (counterblow) fracture?

Answer 11

No fracture occurs at point of impact

Fracture occurs at opposite side of cranium

Question 12

What is a simple fracture?

Answer 12

Break in the bone without damage to the skin

Question 13

What is a compound fracture?

Answer 13

Break in, or loss of, skin & splintering of the bone

+ brain injury & bleeding

Question 14

What is a basal skull fracture?

Answer 14

Fracture of base of skull

Presents with Battle’s sign (ecchymosis -bruising - of the mastoid process of the temporal bone)

Question 15

What is the Pterion?

Answer 15

H-shaped junction of 4 bones
lateral aspect of skull
thinnest part of calvaria

Bone fragments from fracture may rupture middle meningeal artery > extradural haemorrhage

Question 16

Which 4 bones make up the pterion?

Answer 16

Frontal
Parietal
Sphenoidal (greater wing)
Temporal

Question 17

How might infection spread from the scalp to the skull?

Answer 17

Superficial veins of the scalp > Emissary veins > Diploic veins > Intracranial venous sinuses

May cause osteomyelitis

Question 18

Name the foramen of the calvaria (6)

Answer 18

Foramen magnum
Foramen ovale
Foramen spinosum
Foramen lacerum
Carotid canal
Jugular foramen

Question 19

Name the 9 bones that make up the facial skeleton

Answer 19

Frontal
Zygomatic (2)
Maxilla (2)
Palatine (2)
Nasal (2)
Lacrimal (2)
Inferior concha (2)
Vomer
Mandible

Question 20

What is the function of the Frontal bone?

Answer 20

Forms the skeleton of the forehead
Part of the floor of the cranial cavity
Roof of the orbit

Just above orbital margin is a sharp bony ridge - Supraciliary Arch

Question 21

What is the function of the Zygomatic bones?

Answer 21

Cheek bones

Lie on inferolateral sides of the orbit

Question 22

What is the function of the Maxillae?

Answer 22

Makes up large part of upper facial skeleton

Form upper jaw (fixed to cranial base)

Question 23

What is the function of the Mandible?

Answer 23

Movable as it articulates with the cranial base

TMJ

Question 24

Name some common facial fractures

Answer 24

Car accidents, fistfights, falls
commonly involve nasal bones

Maxillofacial fractures - massive facial trauma
hard blow to lower jaw, fracture of neck of mandible (TMJ dislocation)

Question 25

What is a ‘black eye’

Answer 25

Skin bruising around the orbit

tissue fluid and blood accumulate in surrounding connective tissue

Question 26

What can cause profuse bleeding to the face?

Answer 26

Trauma/blow to supraciliary arches causing laceration of skin

Question 27

What is malar flush?

Answer 27

Redness of skin covering the zygomatic bones

Associated with mitral stenosis