Chiasmatic groove

Groove whose anterior border is a ridge bounding the sphenoid bone

Chiasmatic groove
ethmoid bone. Upper surface. (Sulcus chiasmaticus labeled at center)
Base of the skull. Upper surface. (Sphenoid bone is yellow; chiasmatic groove labeled at center left, fourth from the top of the labels near the yellow region.)
Details
Identifiers
Latin	sulcus praechiasmaticus, sulcus chiasmaticus
TA98	A02.1.05.005
TA2	588
FMA	75760
Anatomical terms of bone [edit on Wikidata]

The chiasmatic groove (chiasmatic sulcus, optic groove, prechiasmatic sulcus) is a transverse^[1] groove upon the superior aspect of the body of sphenoid bone^[1]^[2]^: 509 within the middle cranial fossa.^[2]^: 508-509 It is bounded anteriorly by the sphenoidal limbus (a variably prominent ridge also representing the posterior boundary of the sphenoidal jugum^[3]), and posteriorly by the tuberculum sellae.^[1] The opening of each optic canal is placed at either lateral end of the chiasmatic sulcus. The optic chiasm is situated superior and quite posterior to the chiasmatic groove (and not against the groove as the name suggests).^[2]^: 509

References

^ ^a ^b ^c "chiasmatic sulcus". TheFreeDictionary.com. Retrieved 2023-08-01.
^ ^a ^b ^c Sinnatamby, Chummy S. (2011). Last's Anatomy (12th ed.). ISBN 978-0-7295-3752-0.
^ "limbus sphenoidalis". TheFreeDictionary.com. Retrieved 2023-08-01.

External links

figures/chapter_42/42-18.HTM: Basic Human Anatomy at Dartmouth Medical School
Anatomy image: skel/internal2 at Human Anatomy Lecture (Biology 129), Pennsylvania State University (#7)

Neurocranium of the skull

Occipital

Squamous part	external Inion/External occipital protuberance Occipital bun External occipital crest Nuchal lines Suprainiac fossa planes Occipital Nuchal internal Cruciform eminence Internal occipital protuberance 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 foramen Brow ridge Foramen 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