Cranial Bones

Question 1

How many bones makes up the skull?

Answer 1

22
- 8 cranial
- 14 facial

Question 2

Name the 8 cranial bones

Answer 2

“Eight Osseous Parts Form The Skull”
Ethmoid
Occipital
Parietal (2)
Frontal
Temporal (2)
Sphenoid

Question 3

Where does the ethmoid bone sit?

Answer 3

Between the 2 orbits (eye sockets) and makes up the inner part of the orbits

Question 4

What does the ethmoid bone articulate with?

Answer 4

Frontal and sphenoid bones

Question 5

Name the 2 important features of the ethmoid bone?

Answer 5

• Cribriform plate - olfactory nerve passes
• Crista galli - attatchment of meninges (layers of brain)

Question 6

Where do you find the occipital bone?

Answer 6

Back of the skull

Question 7

What does the occipital bone protect?

Answer 7

cerebellum
Brain stem
Occipital lobe of the brain

Question 8

What are the important features of the occipital bone?

Answer 8

• most posterior cranial bone
• Foramen magnum- located at base of occipital bone. Brain stem travels through. connects brain to spinal cord. Where Spinal cord exits the skull
• Hypoglossal canals - cranial nerve xll (hypoglossal)

Question 9

What does the occipital bone articulate with?

Answer 9

Parietal
Temporal
Sphenoid
First cervical (neck)
Vertebra (“atlas”)

Question 10

Where do you find the parietal bone?

Answer 10

Two parietal bones - one located on either side of top of skull

Question 11

Where do you find the frontal bone?

Answer 11

“Forehead” - makes up top area of each orbits
Connects to parietal bone

Question 12

Where do you find the temporal bone?

Answer 12

Two. One located on either side of skull (near ears)

Question 13

What are the 3 parts of the temporal bone?

Answer 13

Squamous (flat)
- articulates with zygomatic bones
- articulate Fossa and articulate eminence link with the mandible

Tympanic (Ear)
- external auditory meatus (outer ear to ear drum)
- petrotympanic fissure (chords tympani nerve)

Peatrous (floor)
- mastoid process - air spaces (mastoid air cells) in ear cavity; site of attatchment of the sternocleidomastoid muscle
- Styloid process - attachment of tongue and pharyngeal muscles
- Jugular foramen - internal jugular vein and cranial nerves travel through here
- Carotid canal - internal carotid artery

Question 14

Name the 3 important sutures (joints)?

Answer 14

Coronal suture
Sagittarius suture
Lambdoidal suture

Question 15

Name the 4 paranasal sinuses?

Answer 15

Frontal
Ethmoid
Sphenoid
Maxillary

Question 16

Which of openings does the nerve go through in the sphenoid bone?

Answer 16

• superior orbital fissure
  -Foramen rotundum
• Foramen Ovale

Question 17

Where do you find the Sphenoid bone?

Answer 17

Spans width of cranial floor

Question 18

What does the sphenoid bone articulate with?

Answer 18

All other cranial bones and some facial bones

Question 19

Where does the pituitary gland sit? (Sphenoid bone)

Answer 19

Sella turcica

Question 20

Important features of the Sphenoid bone?

Answer 20

• Contains the sphenoidal sinuses
• pterygoid process - make up the pterygoid plates (lateral and medial) - attatchment of muscles of mastication (chewing)