Cranium and Vertebral Column Flashcards (Vocabulary)

Expert Station 3 (Cranium)

  • Ethmoid bone

    • Location: part of the anterior skull, between the nasal cavity and orbits; forms part of the cranial base and medial wall of orbits.

    • Key components related to this station:

    • Cribriform plate

    • Crista galli

    • Perpendicular plate

    • Significance: contributes to the nasal cavity structure and the nasal septum; cribriform plate contains olfactory foramina for CN I; crista galli provides attachment for falx cerebri.

  • Cribriform plate

    • Part of the ethmoid bone; perforated with numerous olfactory foramina.

    • Significance: allows passage of olfactory nerve fibers (CN I) from the nasal cavity to the olfactory bulbs.

  • Crista galli

    • A vertical (sagittal) projection of the ethmoid bone.

    • Significance: attachment point for the falx cerebri (dural reflections).

  • Perpendicular plate

    • Part of the ethmoid bone; forms the superior portion of the nasal septum.

    • Significance: articulates with the vomer to contribute to the nasal septum.

  • Vomer bone

    • A plow-shaped bone forming part of the nasal septum.

    • Significance: completes the posterior and inferior portion of the nasal septum, articulating with the perpendicular plate of the ethmoid.

  • Nasal septum

    • The partition dividing the nasal cavity into left and right sides.

    • Formation: composed of the perpendicular plate of the ethmoid and the vomer.

    • Significance: supports airway direction and mucosal distribution.

  • Zygomatic bones

    • Also known as cheekbones; form the prominence of the cheeks.

    • Significance: contribute to the lateral wall and orbit structure; articulate with the maxilla, temporal bone, frontal bone, and sphenoid.

  • Temporal bones

    • Location: lateral sides of the skull; contain auditory and vestibular apparatus.

    • Key features related to this station:

    • External acoustic (auditory) meatus

    • Internal acoustic (auditory) meatus

    • Mastoid process

    • Styloid process

    • Mandibular fossa

    • Carotid canal

    • Significance: housing for middle and inner ear; TMJ involvement via mandibular fossa; provides passage for major vessels and nerves.

  • External acoustic (auditory) meatus

    • Passage leading to the tympanic membrane (ear canal).

    • Significance: external ear canal for sound transmission to the eardrum.

  • Internal acoustic (auditory) meatus

    • Canal within the temporal bone.

    • Significance: transmits facial nerve (CN VII) and vestibulocochlear nerve (CN VIII) from the pons to the inner ear and face.

  • Mastoid process

    • Bony projection on the temporal bone posterior to the ear canal; contains air cells.

    • Significance: attachment for neck muscles; clinical note: mastoiditis risk in infections.

  • Styloid process

    • A slender projection from the temporal bone.

    • Significance: attachment for ligaments and muscles of the tongue and pharynx.

  • Mandibular fossa

    • Depression on the temporal bone just anterior to the external auditory meatus.

    • Significance: articulation site for the condyle of the mandible (forms part of the temporomandibular joint).

  • Carotid canal

    • Canal within the temporal bone.

    • Significance: transmits the internal carotid artery into the cranial cavity.

  • Shared feature: Jugular foramen (occipital and temporal bones)

    • Location: base of the skull, formed by parts of the occipital and temporal bones.

    • Significance: transmits the internal jugular vein and cranial nerves IX (glossopharyngeal), X (vagus), and XI (accessory).

  • Sphenoid bone

    • Central skull bone; spans across the middle of the cranial floor; keystone of the skull base.

    • Significance: contributes to the eye sockets and cranial openings; houses the sella turcica.

  • Superior orbital fissure

    • A slit between the lesser wing of the sphenoid and the frontal bone/orbit.

    • Significance: transmits CN III (oculomotor), CN IV (trochlear), CN VI (abducens), CN V1 (ophthalmic), and superior ophthalmic vessels.

  • Inferior orbital fissure

    • Gap between the maxilla and the sphenoid in the orbit.

    • Significance: transmits infraorbital nerve (V2) and vessels; also allows passage of other orbital structures.

  • Optic canal

    • Passage within the sphenoid bone.

    • Significance: transmits optic nerve (CN II) and ophthalmic artery.

  • Foramen rotundum

    • Opening in the sphenoid bone.

    • Significance: transmits the maxillary nerve (CN V2).

  • Foramen ovale

    • Opening in the sphenoid bone.

    • Significance: transmits the mandibular nerve (CN V3) and accessory meningeal artery; also carries other small branches.

  • Foramen spinosum

    • Opening in the sphenoid bone.

    • Significance: transmits the middle meningeal artery and the meningeal branch of the mandibular nerve.

  • Sella turcica

    • A saddle-shaped depression in the body of the sphenoid bone.

    • Significance: houses the pituitary gland (hypophysis).

Expert Station 4 (Vertebral Column, Thoracic Cage)

  • Intervertebral disc

    • Location: between adjacent vertebral bodies along the vertebral column.

    • Composition: annulus fibrosus (outer ring) and nucleus pulposus (inner gel-like core).

    • Function: provides cushioning and allows slight movement between vertebrae; distributes loads; contributes to height.

    • Clinical relevance: degeneration with age; disc herniation occurs when nucleus pulposus protrudes through a weakened annulus fibrosus, potentially compressing spinal nerves.