MEDICAL GROSS ANATOMY

2008

HEAD AND NECK

 

PASSAGEWAYS IN THE SKULL
 

 

Anterior Aspect of the Skull

Supraorbital foramen (notch)

Infraorbital foramen

Mental foramen

Zygomaticofacial foramen

 

Lateral Aspect of the Skull

Mandibular Notch

 

Posterior Aspect of the Skull

Mastoid emissary foramen (variable and inconstant)

Condylar canal (an inconstant emissary foramen)

 

Vertical Aspect of the Skull

Bregma (site of anterior fontanelle)

Lambda (site of posterior fontanelle)

Parietal emissary foramen (inconstant)

 

Inferior Aspect of the Skull

Incisive fossa

Greater palatine foramen

Lesser palatine foramen (foramina)

**Palatovaginal canal

Foramen ovale

Foramen spinosum

*Groove for the pharyngotympanic tube (auditory, Eustachian tube)

Foramen lacerum (Not a passageway, landmark only!)

Carotid canal (cervical, external, inferior entrance)

Tympanic canaliculus

Jugular fossa (leading upward to jugular foramen)

**Mastoid canaliculus

**Tympanomastoid fissure

Stylomastoid foramen

**Posterior and anterior canaliculi for the chorda tympani

**Petrotympanic fissure

Hypoglossal canal

Foramen magnum

Condylar canal

Mastoid emissary foramen


 

Internal Aspect of the Skull Base

Anterior Cranial Fossa

Groove for the superior sagittal sinus

Foramen cecum

Cribriform plate and foramina for olfactory nerves

**Foramina for the anterior ethmoidal nerve

Middle Cranial Fossa

Optic canal (cranial entrance)

Chiasmatic groove

Superior orbital fissure

Foramen rotundum

Foramen ovale

*Trigeminal fossa (for the trigeminal ganglion)

Foramen spinosum

Grooves for middle meningeal vessels

Carotid groove (on body of the sphenoid)

**Pterygoid (Vidian) canal (posterior entrance)

Carotid canal (cranial, internal, superior entrance)

Foramen lacerum (Not a passageway, landmark only!)

*Hiatus and groove for the greater petrosal nerve

*Hiatus and groove for the lesser petrosal nerve

Posterior Cranial Fossa

*Groove for the superior petrosal sinus

*Groove for the inferior petrosal sinus

Internal auditory (acoustic) meatus (and entrance to the Facial canal)

Foramen magnum

Hypoglossal canal

Condylar canal

Jugular foramen

Groove for the sigmoid sinus

Groove for the transverse sinus

Confluence of the sinuses

Groove for the occipital sinus

Groove for the superior sagittal sinus

 

Mandible

Outer Aspect

Mental foramen

Mandibular notch

Inner Aspect

Mandibular foramen

Mylohyoid groove


 

Orbit

medial wall

Nasolacrimal fossa and canal

Anterior ethmoidal foramen

Posterior ethmoidal foramen

apex

Optic canal (orbital entrance)

lateral wall

Superior orbital fissure

Inferior orbital fissure

Zygomatico-orbital foramen (foramina)

floor

Infraorbital groove and canal

 

Paranasal Air Sinuses

Frontal

Maxillary

Ethmoidal (anterior, middle and posterior ethmoid air cells)

Sphenoidal

 

Nasal Cavity

roof

Cribriform plate and foramina for olfactory nerves

*Foramen for anterior ethmoidal nerve (nasal entrance)

lateral wall (intact)

Nasal meati – superior, middle, inferior

Sphenopalatine foramen

lateral wall (conchae removed)

Frontonasal duct

Infundibulum

Hiatus semilunaris

Ethmoidal bulla

Maxillary hiatus

Nasolacrimal canal

medial wall

Grooves for olfactory nerves

Groove for the nasopalatine nerve

floor

Incisive canal

anterior wall

Anterior nasal aperture

posterior wall

Entrance of the sphenoidal sinus (above)

Posterior nasal aperture, or choana (below)


 

Temporal Fossa

anterior wall

*Zygomaticotemporal foramen

medial wall

Pterion (related to intracranial position of the middle meningeal vessels)

 

Infratemporal Fossa

lateral wall

Mandibular notch

Mandibular foramen

Mylohyoid groove

anterior wall

*Posterior superior alveolar grooves and foramina

medial wall

Pterygomaxillary fissure

roof

Foramen ovale

Foramen spinosum

*Petrotympanic fissure

*Groove for the pharyngotympanic tube (auditory, Eustachian tube)

 

Pterygopalatine Fossa

lateral wall

Pterygomaxillary fissure

medial wall

*Sphenopalatine foramen

**Palatovaginal canal

posterior wall

**Pterygoid (Vidian) canal

anterior wall

Inferior orbital fissure

roof

Foramen rotundum

floor

Greater palatine canal

 

*/** Structures that are elusive (*) or obscure (**).  These will be demonstrated during the scheduled skull presentations.  Look for them on your own, but donŐt hang up over it.  Come to the Faculty for help and/or sign up for a small-group session.

 

A number of emissary foramina have been listed, even though most are variable or inconstant.  Find one of these in your skull and understand that they represent direct communications between intracranial dural venous sinuses and veins of the scalp.