Subarcuate fossa

The subarcuate fossa is a shallow^[1] depression upon the internal surface of the petrous part of the temporal bone^[2] forming the wall of the posterior cranial fossa. The fossa accommodates the flocculus of the cerebellum. It is situated lateral/posterior to the internal auditory meatus.^[1]

Subarcuate fossa
Left temporal bone. Inner surface. (Subarcuate fossa not labeled, but aquaeductus vestibuli labeled at lower right.)
Base of the skull. Upper surface. (Subarcuate fossa not labeled, but temporal bone is identified in pink, and "Eminentia arcuata" (i.e. arcuate eminence, corresponding to the superior semicircular canal) is labeled.)
Details
Identifiers
Latin	fossa subarcuata ossis temporalis
TA98	A02.1.06.034
TA2	672
FMA	56418
Anatomical terms of bone [edit on Wikidata]

Anatomy

The subarcuate fossa is situated posteriorly^[3]: 568 and superiorly^[3]: 737 between the opening of the vestibular aqueduct and opening of internal auditory meatus.^{[3]: 568, 737}

The surface of the subarcuate fossa is lined with dura mater and lodges the endolymphatic sac and duct, as well as a minute artery and vein;^[3]: 568 some veins from the mucosa of mastoid antrum enter the cranial cavity at the subarcuate fossa to drain at the superior petrosal sinus - they are remnants of larger subarcuate veins of childhood and represent a possible route of intracranial infectious spread.^[3]: 749

Other animals

It is extensive in most primates (except for great apes) and nearly all mammals. In these animals, the subarcuate fossa houses a part of the cerebellum, the petrosal lobe.^[4][5]