Head: Internal Skull

Question 1

Anterior Cranial Fossa

Answer 1

• Frontal lobes sit here

Question 2

Anterior Cranial Fossa is formed by

Answer 2

• Frontal bone
• Ethmoid bone
• Sphenoid bone

Question 3

Orbital Plate of Frontal Bone

Answer 3

• Forms the roof of the orbit

Question 4

Ethmoid Bone structures

Answer 4

• Cribiform plate

- Crista galli

Question 5

Sphenoid Bone structures

Answer 5

• Body and lesser wings

- Anterior clinoid process

Question 6

Crista Galli

Answer 6

• Attachment of cranial dura mater (falx cerebri)

Question 7

Openings of the Anterior Cranial Fossa

Answer 7

• Foramina of cribriform plate

- Foramen cecum

Question 8

Foramina of Cribriform Plate

Answer 8

• Passage of bipolar neurons of olfactory nerve (CN I)

Question 9

Foramen Cecum

Answer 9

• Emissary vein from nasal cavity draining to cranial sinuses (not always present)

Question 10

Middle Cranial Fossa

Answer 10

• Temporal lobes of the brain are found here

Question 11

Middle Cranial Fossa formed by

Answer 11

• Temporal bone
• Sphenoid bone
• Sella turcica

Question 12

Posterior boundary of Middle Cranial Fossa

Answer 12

• Crest of the petrous ridge (temporal bone)

- Dorsum sellae

Question 13

Sella Turcica contains

Answer 13

• Tuberculum sellae
• Hypophyseal fossa: houses pituitary gland
• Dorsum sellae
• Posterior clinoid process: dural attachment

Question 14

Hypophyseal Fossa

Answer 14

• Houses pituitary gland

Question 15

Posterior Clinoid Process

Answer 15

• Dural attachment

Question 16

Openings in Middle Cranial Fossa

Answer 16

• Superior orbital fissure
• Foramen rotundum
• Foramen ovale
• Foramen spinosum
• opening for carotid canal
• Foramen lacerum
• Optic canal
• Groove for greater petrosal nerve
• Groove for lesser petrosal nerve

Question 17

Superior Orbital Fissure

Answer 17

• Communicates with orbit

Question 18

Foramen Rotundum

Answer 18

• Communicates with pterygopalatine fossa

Question 19

Foramen Ovale

Answer 19

• Communicates with infratemporal fossa

Question 20

Foramen Spinosum

Answer 20

• Communicates with infratemporal fossa

Question 21

Foramen Lacerum

Answer 21

• Typically closed by cartilage
• Small meningeal vessels pass through
• Internal carotid and some nerves pass horizontally across

Question 22

Optic Canal

Answer 22

• Communicates with orbit

Question 23

Posterior Cranial Fossa

Answer 23

• Deepest cranial fossa

- Houses the cerebellum, pons, and medulla

Question 24

Posterior Cranial Fossa Contains

Answer 24

• Dorsum sellae
• Crest of petrous ridge separate from middle cranial fossa
• Clivus
• Internal occipital protuberance
• Internal occipital crestgroove for transverse and sigmoid sinuses

Question 25

Openings in Posterior Cranial Fossa

Answer 25

- Foramen magnum - Hypoglossal canal - Jugular foramen - Internal acoustic meatus