Craniovertebral Joints and the Pterygopalatine Fossa

Craniovertebral Joints

atlanto-occipital joints – synovial articulations of the two occipital condyles and the superior articular facets of atlas

allows for nodding of head

atlanto-axial joints – synovial joints; two between the superior facets of axis and the inferior facets of atlas, one between the dens of axis and the anterior arch of atlas

allows rotation of the skull/atlas on axis as in shaking head ‘no’

Ligaments

anterior occipital membrane – a continuation of the anterior longitudinal ligament; from anterior arch of atlas to anterior margin of foramen magnum; outermost anterior ligament

tectorial membrane – a continuation of the posterior longitudinal ligament; attaches to the anterior margin of the foramen magnum; lies deep to the anterior occipital membrane

posterior occipital membrane – a continuation of the ligamentum flavum; from posterior arch of atlas to posterior margin of foramen magnum; is pierced by the vertebral artery before it enters the skull

cruciform ligament – attaches the axis to the atlas and the skull; has three parts

(1) transverse ligament of the dens – passes from the inside of the anterior arch of the atlas, around the dens, to attach to the inside of the anterior arch on the other side

(2) superior longitudinal bands – pass from the transverse ligament to the occipital bone

(3) inferior longitudinal bands – pass from the transverse ligament to the body of axis

dura mater –continuous from cranial cavity; runs through foramen magnum and is just deep to tectorial membrane; below C2, dura separates from posterior longitudinal ligament to form a sub-dural space filled with fat and a venous plexus

Pterygopalatine Fossa

boundries:

superior: greater wing of the sphendoid bone, but also opens into the inferior orbital fissure

inferior: pyramidal process of palatine bone; closed except for the palatine foramina

lateral: open to the infratemporal fossa

medial: vertical plate of the palatine bone

posterior: pterygoid process of the sphenoid

anterior: maxilla

contents: maxillary nerve (V²), pterygopalatine ganglion, third part of maxillary a

communications: the fossa communicates with many other area of the skull; the table sumarizes the communications, what’s on the other side, and what runs through the communication

This opening...	communicates with...	and carries...
pterygomaxillary fissure	infratemporal fossa	maxillary artery
sphenopalatine foramen	nasal cavity	nasopalatine artery and branches of V2
posterior superior alveolar foramen	thin wall of maxillary sinus	posterior superior alveolar branches of maxillary artery and of V2
inferior orbital fissure	orbit	inferior orbital artery and nerve (and zygomatic branches)
palatine canal(s)	oral cavity (on palate)	greater and lesser palatine arteries and nerves
foramen rotundum	middle cranial fossa	maxillary nerve (V2)
pterygoid canal (Vidian canal)	foramen lacerum	Vidian nerve
pharyngeal canal	vault of nasopharynx	small artery and branch of V2