Foramen rotundum

Foramen rotundum of Sphenoid
Sphenoid bone. Upper surface. (Foramen rotundum labeled at center left)
Base of the skull. Upper surface. Sphenoid is yellow, and arrows indicate the foramen rotundum.)
Details
Identifiers
Latin	foramen rotundum ossis sphenoidalis
TA	A02.1.05.035
FMA	53154
*Anatomical terms of bone* [edit on Wikidata]

The foramen rotundum is a circular hole in the sphenoid bone that connects the middle cranial fossa and the pterygopalatine fossa.

Structure

The foramen rotundum is one of the several circular apertures (the foramina) located in the base of the skull, in the anterior and medial part of the sphenoid bone.

The mean area of the foramina rotunda is not considerable, which may suggest that they play a minor role in the dynamics of blood circulation in the venous system of the head.^[1]

Development

The foramen rotundum evolves in shape throughout the fetal period, and from birth to adolescence. It achieves a perfect ring-shaped formation in the fetus after the 4th fetal month. It is mostly oval-shaped in the fetal period, and round-shaped after birth (generally speaking). After birth, the rotundum is about 2.5 mm and in 15- to 17-year olds about 3 mm in length. The average diameter of the foramen rotundum in adults is 3.55 mm. This was according to a developmental study published in The Hokkaido Journal of Medical Science on the foramen ovale, the foramen spinosum and the foramen rotundum, and according to a study about the postnatal enlargement of the foramina rotundum, ovale and spinosum and their topographical changes published in the Anatomischer Anzeiger.^[2]^[3]

Function

The maxillary branch (V₂) of the trigeminal nerve (CN V) passes through and exits the skull via the pterygopalatine fossa and the foramen rotundum.

History

Etymology

Foramen is the Latin term designating a hole-like opening. It derives from the Latin forare meaning to bore or perforate. Here, the opening is round as indicated by the Latin rotundum meaning round.

Additional images

Horizontal section of nasal and orbital cavities.
Medial wall of left orbit. The lowest label among those at upper right of the image reads Probe in foramen rotundum.
Foramen rotundum
Labeled image of interior skull base.

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

↑ Reymond J, Charuta A, Wysocki J (2005). "The morphology and morphometry of the foramina of the greater wing of the human sphenoid bone". Folia Morphologica. 64 (3): 188–93. PMID 16228954.
↑ Yanagi S (1987). "Developmental studies on the foramen rotundum, foramen ovale and foramen spinosum of the human sphenoid bone". The Hokkaido Journal of Medical Science. 62 (3): 485–96. PMID 3610040.
↑ Lang J, Maier R, Schafhauser O (1984). "Postnatal enlargement of the foramina rotundum, ovale et spinosum and their topographical changes". Anatomischer Anzeiger. 156 (5): 351–87. PMID 6486466.

External links

Anatomy photo:22:os-0905 at the SUNY Downstate Medical Center
cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (V)
Superior view of the base of the skull at winona.edu

The neurocranium of the skull

Occipital

Squamous part	external Inion/External occipital protuberance External occipital crest Nuchal lines planes Occipital Nuchal internal Cruciform eminence Internal occipital protuberance Sagittal sulcus Internal occipital crest Groove for transverse sinus

Lateral parts	Condyle Condyloid fossa Condylar canal Hypoglossal canal jugular Jugular process Jugular tubercle

Basilar part	Pharyngeal tubercle Clivus

Other	Foramen magnum Basion Opisthion

Parietal

Frontal

Squamous part	Frontal suture Frontal eminence external Superciliary arches Glabella foramina Supraorbital Cecum Zygomatic process internal Sagittal sulcus Frontal crest

Orbital part	Ethmoidal notch Fossa for lacrimal gland Trochlear fovea Frontal sinus Frontonasal duct

Temporal

Squamous part	Articular tubercle Suprameatal triangle Mandibular fossa Petrotympanic fissure Zygomatic process

Mastoid part	Mastoid foramen Mastoid process (Mastoid cells) Mastoid notch Occipital groove Sigmoid sulcus Mastoid antrum (Aditus)

Petrous part	Carotid canal Facial canal Hiatus Internal auditory meatus Cochlear aqueduct Stylomastoid foramen fossae Subarcuate fossa Jugular fossa canaliculi Inferior tympanic Mastoid Styloid process Petrosquamous suture (note: ossicles in petrous part, but not part of temporal bone)

Tympanic part	Suprameatal spine

Sphenoid

Surfaces	Superior surface: Sella turcica Dorsum sellae Tuberculum sellae Hypophysial fossa Posterior clinoid processes Ethmoidal spine Chiasmatic groove Middle clinoid process Petrosal process Clivus Lateral surface: Carotid groove Sphenoidal lingula Anterior surface: Sphenoidal sinuses

Great wings	foramina Rotundum Ovale Vesalii Spinosum Spine Infratemporal crest Sulcus of auditory tube

Small wings	Superior orbital fissure Anterior clinoid process Optic canal

Pterygoid processes	fossae Pterygoid Scaphoid pterygoid plates Lateral Medial Pterygoid canal Hamulus

Other	Body Sphenoidal conchae

Ethmoid

Plates	Cribriform plate Crista galli Olfactory foramina Perpendicular plate

Surfaces	Lateral surface Orbital lamina Uncinate process Medial surface Supreme nasal concha Superior nasal concha Superior meatus Middle nasal concha Middle meatus

Labyrinth	Ethmoid sinus ethmoidal foramina Posterior Anterior

Foramina of the skull (and canals, fissures, meatus, and hiatus)

Anterior cranial fossa

to Orbit:	ethmoidal foramina anterior posterior

to Nasal cavity:	olfactory foramina (CN-I) foramen cecum

Middle cranial fossa

to Orbit:	optic canal (CN-II) superior orbital fissure (CN-III,IV,V1,VI)

to Pterygopalatine fossa:	foramen rotundum (CN-V2) pterygoid canal

to Infratemporal fossa:	foramen ovale (CN-V3) foramen spinosum/carotid canal

other:	foramen lacerum hiatus for greater petrosal nerve hiatus for lesser petrosal nerve sphenoidal emissary foramen

Posterior cranial fossa

internal auditory meatus/facial canal/stylomastoid foramen (CN-VII,VIII)
jugular foramen (CN-IX,X,XI)
foramen magnum (CN-XI)
hypoglossal canal (CN-XII)
condylar canal
mastoid foramen

Orbit

to Nasal cavity:	nasolacrimal canal

to face:	supraorbital notch foramen infraorbital foramen groove zygomatic foramen -facial -temporal

to Pterygopalatine fossa:	inferior orbital fissure

other:	Inferior orbital fissure Fossa for lacrimal sac

Pterygopalatine fossa

to Nasal cavity:	sphenopalatine foramen

to Oral cavity:	greater palatine canal foramen lesser palatine canals foramina

to Infratemporal fossa:	pterygomaxillary fissure

to Nasopharynx:	palatovaginal canal

to oral cavity:	incisive canals incisive foramen

to nasal cavity:	Foramen vomerinum Meatus vomerinus Fissura vomerina Hiatus vomerinus

Other

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