Neuroanatomy: Spinal Cord, Skull, Vertebral Column, and Clinical Correlates

Comprehensive vocabulary flashcards covering neuroanatomy lectures on the skull, cranial fossae, vertebral column, spinal cord gross anatomy, internal structure, ascending and descending tracts, and AI applications.

Central Nervous System (CNS)

The division of the nervous system consisting of the brain (forebrain, midbrain, and hindbrain) and the spinal cord.

Peripheral Nervous System (PNS)

The division of the nervous system consisting of $12$ pairs of cranial nerves that exit the skull through foramina and $31$ pairs of spinal nerves that exit the vertebral column through intervertebral foramina, along with their associated ganglia.

Forebrain (Prosencephalon)

The anterior part of the brain composed of the telencephalon (cerebrum) and the diencephalon (thalamus and hypothalamus).

Hindbrain (Rhombencephalon)

The posterior part of the brain comprising the cerebellum, pons, and medulla oblongata.

Diploë

The layer of spongy bone situated between the external and internal tables of compact bone in the skull bones.

Sutures

Immobile joints that unite the separate bones of the skull, held together by connective tissue termed sutural ligaments.

Bones of the Cranium

A group of $8$ bones enclosing the brain: $1$ frontal, $2$ parietal, $1$ occipital, $2$ temporal, $1$ sphenoid, and $1$ ethmoid.

Facial Bones

A group of $14$ bones comprising $2$ zygomatic, $2$ maxillae, $2$ nasal, $2$ lacrimal, $1$ vomer, $2$ palatine, $2$ inferior conchae, and $1$ mandible.

Anterior Cranial Fossa

The cranial fossa that lodges the frontal lobes of the cerebral hemispheres, bounded anteriorly by the frontal bone (with a midline crest for the falx cerebri) and posteriorly by the lesser wing of the sphenoid.

Middle Cranial Fossa

The cranial fossa consisting of a median raised part formed by the sphenoid body and expanded lateral parts lodging the temporal lobes, bounded posteriorly by the superior borders of the petrous temporal bones.

Posterior Cranial Fossa

The deepest cranial fossa that lodges the hindbrain (cerebellum, pons, and medulla oblongata), bounded anteriorly by the petrous temporal bone and posteriorly by the squamous occipital bone.

Pterion

The anatomical region on the lateral skull where the frontal, parietal, sphenoid (greater wing), and temporal bones meet, lying directly superficial to the middle meningeal artery.

Cribriform Plate Perforations

Openings located in the ethmoid bone within the anterior cranial fossa that transmit the olfactory nerves.

Optic Canal

An aperture within the lesser wing of the sphenoid bone that transmits the optic nerve and the ophthalmic artery.

Superior Orbital Fissure

A fissure between the lesser and greater wings of the sphenoid that transmits the lacrimal, frontal, trochlear, oculomotor, nasociliary, and abducent nerves, as well as the superior ophthalmic vein.

Foramen Rotundum

A circular canal within the greater wing of the sphenoid bone that transmits the maxillary division of the trigeminal nerve.

Foramen Ovale

An oval aperture in the greater wing of the sphenoid bone transmitting the mandibular division of the trigeminal nerve and the lesser petrosal nerve.

Foramen Spinosum

A small opening in the greater wing of the sphenoid bone that transmits the middle meningeal artery.

Foramen Lacerum

An irregular aperture situated between the petrous part of the temporal bone and the sphenoid bone that transmits the internal carotid artery.

Foramen Magnum

The large opening in the occipital bone that transmits the medulla oblongata, the spinal part of the accessory nerve, and the right and left vertebral arteries.

Hypoglossal Canal

A canal in the occipital bone that transmits the hypoglossal nerve.

Jugular Foramen

An opening located between the petrous temporal bone and the condylar part of the occipital bone transmitting the glossopharyngeal, vagus, and accessory nerves, and where the sigmoid sinus transitions into the internal jugular vein.

Internal Acoustic Meatus

A bony canal in the petrous part of the temporal bone that transmits the vestibulocochlear and facial nerves.

Anterior Fontanelle

A diamond-shaped, unossified membranous space in the neonatal skull between the two halves of the frontal bone and the two parietal bones, closing by $18$ months of age.

Posterior Fontanelle

A triangular membranous interval in the neonatal skull between the two parietal bones and the occipital bone, which closes by the end of the first year of life.

Vertebral Column

The central bony pillar composed of $33$ vertebrae ($7$ cervical, $12$ thoracic, $5$ lumbar, $5$ fused sacral, and $4$ coccygeal) that houses and protects the spinal cord.

Atlas (C1)

The first cervical vertebra, which lacks a body and a spinous process, articulating superiorly with the skull at the atlanto-occipital joint to allow nodding movements.

Axis (C2)

The second cervical vertebra, characterized by the tooth-like odontoid process (dens) that acts as a pivot for rotation of the head.

Vertebra Prominens (C7)

The seventh cervical vertebra, characterized by a long, non-bifid, clinically palpable spinous process.

Anulus Fibrosus

The peripheral fibrocartilaginous portion of an intervertebral disc that is firmly attached to adjacent vertebral bodies and longitudinal ligaments.

Nucleus Pulposus

The central, ovoid mass of gelatinous material within an intervertebral disc that is held under pressure and situated slightly closer to the posterior margin.

Anterior Longitudinal Ligament

A wide, strong ligamentous band extending continuously along the anterior and lateral surfaces of the vertebral bodies and discs from the skull to the sacrum.

Posterior Longitudinal Ligament

A weak, narrow ligamentous band running along the posterior surfaces of the vertebral bodies and intervertebral discs inside the vertebral canal.

Ligamentum Flavum

A specialized elastic ligament connecting the laminae of adjacent vertebrae.

Ligamentum Nuchae

A thick, fibroelastic midline septum formed by expansion of the supraspinous and interspinous ligaments in the cervical region.

Spinal Cord Inferior Termination Level

The lower anatomical boundary of the spinal cord, ending at the lower border of the first lumbar vertebra ($L1$) in adults and at the upper border of the third lumbar vertebra ($L3$) in young children.

Conus Medullaris

The tapering, conical lower end of the spinal cord located at the level of $L1$ in adults.

Filum Terminale

A slender prolongation of the pia mater extending downward from the apex of the conus medullaris to attach to the posterior surface of the coccyx.

Cervical and Lumbar Enlargements

Fusiform enlargements of the spinal cord that give origin to the brachial plexus ($C3-T2$) and the lumbosacral plexus ($L1-S3$), respectively.

Great Anterior Medullary Artery of Adamkiewicz

A major feeder or segmental artery providing significant arterial blood supply to the lower two-thirds of the spinal cord.

Spinal Cord Gray Matter

An inner H-shaped core composed of anterior and posterior gray columns joined by a thin gray commissure enclosing the central canal, with lateral columns present in thoracic and upper lumbar segments.

Spinal Cord Segments to Vertebral Numbers Rule (Lower Thoracic 7-9)

The anatomical rule stating that to determine the underlying spinal cord segment from the lower thoracic spinous processes ($T7-T9$), one adds $3$.

Fasciculus Gracilis and Fasciculus Cuneatus

Ascending tracts in the posterior white column that convey discriminative touch, vibratory sense, and conscious muscle-joint sense ipsilaterally to the medulla oblongata.

Lateral Spinothalamic Tract

An ascending spinal pathway that transmits pain and temperature impulses; second-order neurons in the substantia gelatinosa decussate within one segment to ascend to the thalamus via the spinal lemniscus.

Anterior Spinothalamic Tract

An ascending sensory pathway that conveys light (crude) touch and pressure sensations, decussating obliquely across several segments before ascending in the anterolateral funiculus.

Nucleus Dorsalis (Clarke's Column)

A group of second-order relay neurons in the posterior gray column that gives rise to the posterior and anterior spinocerebellar tracts.

Cuneocerebellar Tract

A pathway originating in the nucleus cuneatus whose fibers (posterior external arcuate fibers) enter the cerebellum through the inferior cerebellar peduncle to convey unconscious muscle-joint sense.

Corticospinal Tracts

Major descending motor pathways originating from pyramidal cells in layer $5$ of the cerebral cortex that descend through the internal capsule and brainstem, decussating in the medulla into lateral and anterior corticospinal tracts.

Rubrospinal Tract

A descending motor pathway originating in the red nucleus of the midbrain tegmentum that facilitates flexor muscle tone and inhibits extensor (antigravity) muscle tone.

Vestibulospinal Tract

A descending motor tract originating from vestibular nuclei in the pons and medulla that facilitates extensor muscles and inhibits flexor muscles to help maintain balance.

Tectospinal Tract

A descending pathway arising from the superior colliculus of the midbrain that mediates reflex postural movements in response to visual stimuli.

Reticulospinal Tracts

Descending brainstem pathways (pontine and medullary) originating from the reticular formation that mediate hypothalamic control of sympathetic and sacral parasympathetic outflow.

Reflex Arc

The basic anatomical pathway underlying an involuntary response to a stimulus, composed of a receptor organ, an afferent neuron, an effector neuron, and an effector organ.

Prolapsed Intervertebral Disc

A clinical lesion occurring when the softer nucleus pulposus herniates through tears in the anulus fibrosus, commonly impinging on adjacent exiting spinal nerve roots.

Artificial Intelligence in Neuroscience

Computational applications encompassing neuroimaging segmentation, brain mapping, disease detection, neurosurgical planning, and research that use neuroanatomical knowledge to interpret neurological data.