Osteology of Skull and Spinal Cord
Major Foramina of the Skull
| Foramen | Vascular Contents | Nerve Contents |
|---|---|---|
| Supraorbital foramen | Supraorbital artery & vein | Supraorbital nerve |
| Infraorbital foramen | Infraorbital artery & vein | Infraorbital nerve |
| Superior orbital fissure | Superior ophthalmic vein | III – IV – V1 – VI |
| Inferior orbital fissure | Inferior ophthalmic veins, Infraorbital artery and vein | Zygomatic and Infraorbital branches of maxillary nerve (V2), Orbital branches of pterygopalatine ganglion |
| Optic canal | Ophthalmic artery | Optic nerve (II) |
| Foramen cecum | Emissary veins to superior sagittal sinus | |
| Cribriform plate | Olfactory nerve bundles (I) | |
| Foramen rotundum | Maxillary nerve (V2) | |
| Foramen ovale | Accessory meningeal artery | Mandibular nerve (V3) |
| Foramen spinosum | Middle meningeal artery | Meningeal branch of the mandibular nerve (V3) |
| Foramen lacerum | Internal carotid artery, artery of pterygoid canal | Nerve of pterygoid canal |
| Internal acoustic meatus | Labyrinthine artery | Facial nerve (VII), vestibulocochlear nerve (VIII) |
| Jugular foramen | Inferior petrosal sinus, sigmoid sinus | Glossopharyngeal nerve (IX), Vagus nerve (X), Accessory nerve (XI) |
| Hypoglossal canal | Hypoglossal nerve (XII) | |
| Foramen magnum | Anterior and posterior spinal arteries, vertebral arteries | Medulla oblongata, Hypoglossal nerve, Cervical components of accessory |
| Stylomastoid foramen | Stylomastoid artery | Facial nerve |
Important Spinal Ligaments
| Ligament | Function | Location |
|---|---|---|
| Anterior longitudinal ligament | Limits over-extension, supports the front of intervertebral discs | Whole spine |
| Posterior longitudinal ligament | Limits over-flexion, supports the back of intervertebral discs | Whole spine |
| Ligamentum flavum | Limits over-flexion | Whole spine |
| Supraspinous ligament | Limits over-flexion | Thoracic & Lumbar spine |
| Interspinous ligament | Limits over-flexion | Lumbar spine |
| Ligamentum nuchae | Limits over-flexion | Cervical spine |
| Alar ligament | Limits neck rotation & lateral flexion | Between Axis & occipital condyles of both sides |
| Transverse ligament | Secures the dense posteriorly | Between two lateral masses of axis |
Important Spinal Joints
| Joint | Location | Type |
|---|---|---|
| Intervertebral synovial joints | Between superior and inferior articular processes | Synovial joint |
| Medial atlanto-axial joint | Between dense (C2) and articular facet (C1), supported posteriorly by transverse ligament | Pivot synovial joint |
| Lateral atlanto-axial joint | Between inferior facet of C1 masses and superior facets of C2 | Plane synovial joint |