Skull

Question 1

Cranium

- protects brain and sensory organs

Answer 1

Formed of two parts:-

• Neurocranium
• Visceocranium

Question 2

Neurocranium

• formed of a skull cap (CALVARIA),
• a cranial base (BASICRANIUM)
• an intercranial region (inner surface of base of skull)

Answer 2

formed of 8 bones :-
singular bones - Frontal, Ethmoidal , Occipital
paired bones - Temporal, Parietal

Question 3

Viscerocranium

- comprises the FACIAL BONES in the anterior part of the cranium

Answer 3

Singular bones: -
- Mandible and Vomer
Paired:-
- Maxilla, Inferior Nasal Conchae*, Zygomatic, Palatine, Nasal and Lacrimal
*called turbinates in some textbooks

Question 4

Mandible

Answer 4

Only movable joint of the cranium
articulates with the cranial base : TMJ
- temporomandibular joint

Question 5

What bones make up the NASAL SEPTUM?

*important exam question

Answer 5

• Perpendicular plate of the ETHMOID BONE

- VOMER

Question 6

Pterion

Answer 6

Susceptible to fractures

• weak point of the skull
• located two finger breadths superior and lateral to the edge of the orbit

Question 7

Frontal bone

Answer 7

forms part of the TOP OF THE HEAD

also forms the ROOF OF THE ORBITS

Question 8

Parietal bones

Answer 8

form lateral walls and roof of the cranium

divided approx mid sagitally

Question 9

Occipital bone

Answer 9

Posterior region of the skull

Question 10

Temporal bones

Answer 10

Form the INFERIOR LATERAL WALLS and part of the floor of the cranium

Question 11

Sphenoid bone

- most complex bone in the body

Answer 11

shaped like a BUTTERFLY
unites the cranial and facial bones
Articulates with every other cranial bone and also the palatine bones, zygomatic bones, maxillae and vomer

Question 12

Ethmoid bone

Answer 12

• positioned between the orbits
• forms the anteromedial floor of the cranium, roof of the nasal cavity, part of the medial wall of each orbit and part of the nasal septum

Question 13

Maxilla bone

Answer 13

Forms central part of the facial skeleton

Two unite to form the upper jaw

Question 14

Palatine bones

Answer 14

Small bones, distinct L shape

Form part of the hard palate, nasal cavity and eye orbit

Question 15

Zygomatic bones

A.K.A Cheek bones

Answer 15

form lateral wall of each orbit and the cheeks

Question 16

Lacrimal bone

Answer 16

SMALLEST BONES IN THE SKULL
Form part of the medial wall of each orbit
Have a groove that provides a passageway for the tear duct, which drains into the nasal cavity

Question 17

Nasal bones

*often fractures by blows to the nose

Answer 17

Forms bridge of the nose

Lateral side articulates with the medial edge of the maxilla.

Question 18

Vomer bone

Answer 18

Forms interior posterior part of the nasal septum.
Articulates along midline with both the MAXILLAE and the PALATINE bones
“Wings” articulate superiorly with the sphenoid bone and the perpendicular plate of the Ethmoid bone
- forming together the bony NASAL SEPTUM

Question 19

Inferior Nasal Conchae Bone

Answer 19

located in the lateral wall of the nasal cavity
help create turbulence in inhaled air
has superior and middle counterparts that are part of the ethmoid bone

Question 20

Mandible bone

Answer 20

Forms the entire lower jaw

Supports the lower teeth and provides attachment for the muscle of MASTICATION.

Question 21

Rhinorrhae

Answer 21

CSF leaking out after fracture of the nose

Question 22

Skull air sinuses

• 4 main pairs of cavities in skull
• contains air and mucus which drains through them and out of the nose

Answer 22

• Frontal
• Ethmoid
• Sphenoid
• Maxillary (largest one)

Question 23

Sutures

Answer 23

FIBROUS JOINTS (synarthroses) between bones of the skull, become increasingly immobile and ossified with age.
Everyone has a different suture pattern

Question 24

Bregma point

Lambda point

Answer 24

Bregma - crossover of coronal and sagittal suture

Lambda- crossover of sagittal and lambdoid suture

Question 25

Occipital condyle

Answer 25

Articulates with the Atlas

*skull articulates with the cervical spine via the Occipital Condyle

Question 26

Movements of the Cervical Spine

Answer 26

• Flexion
• Extension
• Lateral flexion (side-to-side)
• Rotation

Question 27

Cervical spine

Answer 27

Top 7 cervical vertebrae provide support for the neck structures