Bones - The Skull

Question 1

What are the two subdivisions of the Skull and what do they represent?

Answer 1

• Neurocranium: The bony box that surrounds the brain

- Viscerocranium: Skeleton of the face

Question 2

What Bones can be seen from the Anterior View of the Skull and are they paired? (Mandible Removed) (4)

Answer 2

• Frontal Bone (unpaired bone)
• Maxilla (upper jaw: paired bone)
• Nasal Bones: nasal bridge where the two bones meet (paired bone)
• Zygomatic Bone: cheeks (paired bone)

Question 3

What Cavities can be seen from an Anterior view of the Skull? (2)

Answer 3

• The Orbital Cavity

- The Nasal Cavity

Question 4

What are the Openings visible in the Orbital Cavity from an Anterior view and what nerves pass through them? (3)

Answer 4

• The Superior Orbital Fissure (passage for Cranial Nerves III, IV, & VI)
• Optic Canal (passage for Cranial Nerve II)
• Inferior Orbital Fissure

Question 5

What is visible in the Nasal Cavity from an Anterior view? (2)

Answer 5

Visible 
- Conchae (bony shelves)
- Inferior Conchae
- Middle Conchae
Not Visible 
- Superior Conchae

Question 6

Describe the Mandible

Answer 6

• Single bone (unpaired)
• Lower Jaw
• Part of the Skull but not the Cranium (cranium is the skull without the mandible)

Question 7

Bones of the Skull visible from a Lateral view and are they single or paired? (8)

Answer 7

• Frontal Bone (single bone)
• Parietal Bone (paired bone)
• Occipital Bone (single bone)
• Lacrimal Bone (lacrimal duct passes through it to the nose)
• Temporal Bone (paired bone)
• Maxilla Bone (paired bone)
• Zygomatic Arch (union of temporal bone and zygomatic bone)
• Mandible

Question 8

What Features of the Temporal Bone can be seen from a Lateral view? (3)

Answer 8

• External Auditory Meatus
• Mastoid Process
• Styloid Process

Question 9

What Features of the Mandible can be seen from a Lateral view? (3)

Answer 9

• Ramus (body)
• Condylar (round shape): articulate with temporal bone in the temporomandibular joint (TMJ)
• Coronoid (triangular and sharp)

Question 10

What Bones can be seen from the Posterior view of the Skull? (3)

Answer 10

• Parietal bones (paired)
• Occipital bone (the bump is called the External Occipital Protuberance)
• Sutural Bones (solid in adults)

Question 11

What is the suture between the Occipital and Parietal Bone called?

Answer 11

Lambdoid Suture

Question 12

What is the Suture called between the two Parietal Bones?

Answer 12

Sagittal Suture

Question 13

What Bones are visible from a Superior view of the Skull? (3) and what is another name for the Superior view?

Answer 13

Bones Visible 
- Frontal Bone
- Parietal Bone
- Occipital Bone
Other Name
- Calvaria

Question 14

What Sutures are visible from the Superior view of the Skull and what bones do they fuse together? (3)

Answer 14

Sutures

• Sagittal Suture: the two parietal bones
• Lambdoid (L-Shaped): between the occipital and parietal bones
• Coronal Suture: between the Frontal and Parietal bones

Question 15

What is the name of the area where the Sagittal and Coronal Sutures meet? (in adults and in neonatal)

Answer 15

Adult
- Bregma
Neonate
- Anterior Fontanel (turns to bone at 12-18 months)

Question 16

What is the name of the area where the Lambdoid and Sagittal Sutures meet in adults and in neonatal?

Answer 16

Adult
- Lambda
Neonate
- Posterior Fontanel (ossifies in 6 months)

Question 17

What are the bones visible from an Inferior view of the Skull? (mandible Removed) (6)

Answer 17

Hard Palate 
- Maxillae
- Palatine
Other Bones
- Sphenoid 
- Temporal 
- Occipital 
- Vomer (single bone)

Question 18

What Bony Features are visible from an Inferior of the Skull? (Mandible Removed) (8)

Answer 18

• Choanae
• Pterygoid Process
• Occipital Condyles
• Zygomatic Arch
• Styloid Process
• Mastoid Process
• External Occipital Protuberance
• Median Palatine Suture

Question 19

What are the 3 identifiable Fossa’s of the Skull from the Superior view of the Cranial Cavity?

Answer 19

• Anterior Cranial Fossa
• Middle Cranial Fossa
• Posterior Cranial Fossa

Question 20

What Bones / Bony Features make up the Anterior Cranial Fossa? (5)

Answer 20

• Frontal Bone
• Sphenoid (lesser wing)
• Ethmoid Bone
  
  • Cribriform Plate
  • Crista Galli

Question 21

What Bones / Bony Features make up the Middle Cranial Fossa? (2)

Answer 21

• Sphenoid (lesser and Greater Wings)

- Temporal Bone

Question 22

What Bones / Bony Features make up the Posterior Cranial Fossa? (2)

Answer 22

• Temporal Bone

- Occipital Bone

Question 23

What are the Major Openings in the Base of the Skull and what passes through them? (12) (sorry need to know these)

Answer 23

Cribriform Plate of Ethmoid (2 openings on either side)
- Olfactory Foramina
- Cranial Nerve I: Olfactory Nerve
Hypophyseal Fossa (sella turcica) in the sphenoid bone
- Pituitary gland (hypophysis)
Optic Canal in Sphenoid Bone 
- Cranial Nerve II: Optic Nerve
Superior Orbital Fissure 
- Cranial Nerves III, IV, & VI
Foramen Rotundum 
- Second Branch of Cranial Nerve V
Foramen Ovale 
- Third Branch of Cranial Nerve V
Foramen Spinosum
- Middle Meningeal Artery
Foramen Lacerum
- Sealed with a layer of cartilage
Internal Acoustic Meatus 
- Cranial Nerve VIII
Jugular Foramen 
- Internal Jugular Vein
Hypoglossal Canal
- Cranial Nerve XII
Foramen Magnum
- Spinal Cord

Question 24

What is the Hardest Part of the Skull, what bone does it belong to, and where is it located? What does blood in the ear mean after a head injury?

Answer 24

Petrous

• Temporal Bone
• Embeds middle and inner ear
• Blood in-ear from head injury means the Petrous might be fractured