Foramens of Cranial Fossae

Foramens of Cranial Fossae-

  • Anterior cranial fossa:
    1. Foramen caecum– emissary vein to superior sagittal sinus.
    2. Anterior ethmoidal foramen– Anterior ethmoidal artery, vein & nerve.
    3. Foramina of Cribriform plate– Olfactory nerve (CN I)
    4. Posterior ethmoidal foramen– Posterior ethmoidal artery, vein & nerve
  • Middle cranial fossa:
    1. Optic canal– Optic Nerve ( CN II), Ophthalmic artery.
    2. Superior Orbital Fissure– Occulomotor Nerve (CN III), Trochlear Nerve (CN IV), Lacrimal, Frontal & Nasocilliary branches of Ophthalmic Nerve (CN V₁), Abducent Nerve (CN VI), Superior Ophthalmic Vein)
    3. Foramen rotundum– Maxillary Nerve (CN V₂)
    4. Foramen ovale– Mandibular Nerve (CN V₃), Accessory Meningeal artery, Lesser Petrosal Nerve
    5. Foramen spinosum– Middle meningeal artery & vein, Meningeal branch of Mandibular Nerve
    6. Foramen lacerum– in this foramen, the greater petrosal nerve joins with the deep petrosal nerve to form the nerve of the pterygoid canal which along with artery of pterygoid canal pass through it. Foramen lacerum is a portal of entry into cranium for tumours (e,g. Nasopharyngeal Ca, Juvenile angiofibroma, Adenoid cystic Ca, Malignant melanoma & Lymphoma)
    7. Carotid canal– Internal carotid artery with its nerve plexus
  • Posterior cranial fossa:
    1. Internal acoustic meatus– Facial Nerve (CN VII), Vetibulocochlear Nerve (CN VIII), Labrynthine artery
    2. Jugular foramen– Inferior petrosal sinus, Glossopharyngeal Nerve (CN IX), Vagus Nerve (CN X), Accessory Nerve (CN XI), Sigmoid sinus, Posterior meningeal artery
    3. Hypoglossal canal– Hypoglossal Nerve (CN XII)
    4. Foramen magnum– Medulla oblongata, Meninges, Vertebral arteries & venous plexuses, Meningeal branches of vertebral arteries, Spinal root of accessory nerve