QS Study

The middle cranial fossa is located, centrally in the cranial floor. It is a butterfly-shaped depression of the skull base, which is narrow in the middle and wider laterally.

The boundary of middle cranial fossa –

(A) Anteriorly:

  1. Posterior border of the lesser wing of sphenoid.
  2. Anterior clinoid process.
  3. Anterior margin of sulcus chiasmatic.

(B) Posteriorly:

  1. Superior border of petrous temporal bone.
  2. The dorsum sellae of the sphenoid.

(C) Laterally:

  1. Greater wing of the sphenoid.
  2. An anteroinferior angle of the parietal bone.
  3. The squamous temporal bone.

(D) Floor: The floor is formed by the body and greater wing of the sphenoid, and the squamous and petrous parts of the temporal bone.

(i) Median area: Body of the sphenoid.

(ii) Lateral area:

  • Greater wing of sphenoid.
  • Petrous temporal bone.
  • Squamous temporal bone.

Boundary of Middle Cranial Fossa

Fig: Boundary of Middle Cranial Fossa

Important structures in middle cranial fossa

(A) In Median area

  1. The sulcus chiasmatic (optic groove).
  2. The optic canal.
  3. The sella turcica.
  4. The tuberculum sellae.
  5. The hypophysial fossa.
  6. The dorsum sellae.

(B) In lateral area –

  1. The superior orbital fissure.
  2. The groove for the middle meningeal vessel.
  3. The trigeminal impression.
  4. The hiatus & groove for greater petrosal nerve.
  5. The hiatus & groove for lesser petrosal nerve.
  6. Arcuate eminence.
  7. The tegmen tympani.

Foramina lying in the middle cranial fossa

  • The foramen rotundum.
  • The foramen ovale.
  • The foramen spinosum.
  • The foramen lacerum.
  • The emissary sphenoidal foramen.
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