The Skull

Question 1

How many bones make up the skull?

What types of joints connect these bones?

Answer 1

22 bones

These are connected by fibrous sutures - a type of joint that is not moveable

The temporomandibular joints are synovial and moveable

Question 2

Label the visible bones of the skull

Answer 2

Question 3

What 2 bones make up the nasal septum?

Answer 3

ethmoid and vomer

Question 4

Why is there only an inferior nasal concha?

Answer 4

The superior and middle conchae are part of the ethmoid bone

Question 5

What are the 4 paranasal sinuses?

Answer 5

1. Frontal sinuses
2. Ethmoidal cells
3. Maxillary sinuses
4. Sphenoidal sinus

Question 6

Label the paranasal sinuses

Answer 6

Question 7

What are the functions of the paranasal sinuses?

Answer 7

1. To lighten the weight of the skull
2. Drainage into specific areas of the nasal cavity
3. Humidify the air

Question 8

What are the meatuses?

what drains into them?

Answer 8

an opening for the passage of air, located underneath the corresponding concha

superior meatus:

• ethmoidal and sphenoidal sinuses drain here

middle meatus:

• maxillary and frontal sinuses drain here

inferior meatus:

• nasolacrimal duct drains here

Question 9

Label the bones of the skull from a lateral view

Answer 9

Question 10

Label the important features of the skull

Answer 10

Question 11

What is significant about the mastoid process?

Answer 11

It is a site for muscle attachment

the sternocleidomastoid muscle attaches here

Question 12

What is the pterion?

why is it clinically significant?

Answer 12

The area where the following bones meet:

1. Frontal
2. Temporal
3. Sphenoid
4. Parietal

The skull is particularly thin at this point and it overlies the middle meningeal artery

Question 13

What can a fracture of the pterion lead to?

Answer 13

fracture here can lacerate the middle meningeal artery (anterior branch), resulting in a extradural haematoma.

Question 14

Label the bones and sutures of the posterior skull

Answer 14

Sagittal suture:

• Between the 2 parietal bones of the skull

Lambdoid suture:

• connects parietal bones with occipital bone

Question 15

What are some significant differences in the skull of a newborn?

Answer 15

The bones have not properly fused together

the spaces between them are fontanelles

Question 16

What is the purpose of fontanelles?

Answer 16

They allow for growth of the brain after birth

they allow for the skull to deform during birth

Question 17

Why is there no mastoid process on the newborn skull?

Answer 17

The mastoid process develops as the sternocleidomastoid muscle develops and begins to be used

Question 18

Label the following fossae and features of the skull

Answer 18

Question 19

Which cranial nerves pass through the structures listed?

Answer 19

Question 20

What are the contents of the 3 cranial fossae?

Answer 20

Anterior cranial fossa:

• Frontal lobe

Middle cranial fossa:

• Temporal lobe

Posterior cranial fossa:

• cerebellum and brainstem

Question 21

Label the following features of the skull

Answer 21

Question 22

Which bones make up the hard palate?

Answer 22

maxilla and palatine bones