Cranial Fossa

Question 1

The artery that passes medial to Anterior clinoid process is …..

Answer 1

ICA

Question 2

Structures passing through optic canal are ……. & …….

Answer 2

• Optic nerve (CN II)
• Ophthalmic artery

Question 3

Attachments of falx cerebri are ……. , ……. , …….

Answer 3

• Crista gali of ethmoid bone
• Frontal crest
• Margins of sagittal sulcus

Question 4

Structures passing through superior orbital fissure

Answer 4

• CN III (sup. & Inf. divisions)
• CN lV
• Branches of CN V1:
  → Lacrimal n.
  → Frontal n.
  → Nasociliary n.
• CN Vl
• Superior & inferior ophthalmic veins

Question 5

Nerves passing through superior orbital fissure (Outside the tendinous ring)

Answer 5

• CN IV
• Lacrimal n.
• Frontal n.

Question 6

Nerves passing through superior orbital fissure (Inside the tendinous ring)

Answer 6

• CN III (sup. & Inf. divisions)
• Nasociliary n.
• CN Vl

Question 7

Foramen Rotandum leads to ……. fossa & transmits …….

Answer 7

• Pterygopalatine fossa
• Maxillary nerve (CN V2)

Question 8

Foramen Ovale leads to ……. fossa
& transmits ……. , ……. , ……. , ……. , ……

Answer 8

Infratemporal fossa

• Mandibular n. (CN V3)
• Motor root of CN V
• Accessory meningeal artery
• Lesser petrosal n.
• Emissiary vein (Connects cavernous
  sinus & pterygoid venous plexus)

Question 9

Foramen Spinosum leads to ……. fossa
& transmits ……. & …….

Answer 9

Infratemporal fossa

• MMA (from maxillary a.)
• Nervus spinosus (from CN V3 trunk)

Question 10

Anterior cranial fossa lodges …….
Middle cranial fossa lodges …….
Posterior cranial fossa lodges …….

Answer 10

• Frontal lobe
• Temporal lobe
• Cerebellum

Question 11

Clivus is formed by ……. & …….

Answer 11

Part of body of sphenoid
Part of occipital bone (Basilar part)

Question 12

Clivus is related to ……. , ……. , …….

Answer 12

• Pons
• Basilar artery
• Basilar venous plexus

Question 13

Foramen Magnum transmits

Answer 13

• Meninges
• Lower part of medulla
• Tonsil of cerebellum
• Spinal root of CN Xl
• Arteries
  → Vertebral a.
  → Anterior spinal a.
  → Posterior spinal a.
• Ligaments
  → Apical ligament of dens
  → Tectorial membrane

Question 14

Internal acoustic meatus transmits

Answer 14

• CN Vll
• CN Vlll
• Labyrinthine artery (from basilar)

Question 15

Jugular foramen transmits

Answer 15

Anteromedial compartment:
- Inf. petrosal sinus

Intermediate compartment:
- CN IX
- CN X
- CN XI

Posterolateral compartment:
- IJV

Question 16

Attachments of falx cerebri

Answer 16

Anteriorly (apex):
- Crista gali of ethmoid bone
- Frontal crest

Superiorly:
Margins of sagittal sulcus

Posteriorly (base):
Upper surface of tentorium cerebelli

Question 17

Attachments of tentorium cerebelli

Answer 17

Attached border:
- Margins of transvers sulcus
- Upper border of petrous bone

Free border:
Two anterior clinoid processes

Question 18

Attachments of falx cerebelli

Answer 18

Superiorly (base):
Tentorium cerebelli

Inferiorly (apex):
Margins of foramen Magnum

Posteriorly:
Internal occipital crest

Question 19

Blood supply of Dura

Answer 19

Ant cranial fossa
- Ant. ethmoidal (Ophthalmic ← ICA)
- Post. ethmoidal. (Ophthalmic ← ICA)
- MMA (Maxillary)

Middle cranial fossa
- MMA (Maxillary)
- Accessory meningeal a. (Maxillary)
- Ascending pharyngeal a. (ECA)

Posterior cranial fossa
- Ascending pharyngeal a. (ECA)
- Occipital a. (ECA)
- Vertebral a. (1st part of subclavian)

Question 20

Nerve supply of Dura

Answer 20

Anterior cranial fossa
- Ant. Ethmoidal n. (Mainly)
- Maxillary n.

Middle cranial fossa
- Ant. ½ → Maxillary n.
- Post ½ → Mandibular n.

Posterior cranial fossa
- Meningeal branches from CN 10 & 12
- Recurrent branches from C1,2,3 ns.