Spinal Cord Anatomy Quiz

Spinal Meninges

• The spinal dura is pierced segmentally by the anterior and posterior roots of the spinal nerves as they exit the cord.
• The subarachnoid space is between the arachnoid and pia mater and is filled with cerebrospinal fluid (CSF).
• The pia mater is vascular and lines the anterior median sulcus, and is prolonged over the spinal nerve roots, blending with their epineurium.
• The filum terminale is a projection of the pia mater below the apex of conus medullaris, attached to the back of the coccyx.

Dentate Ligaments

• The dentate ligaments are special folds of the spinal pia mater that pierce the arachnoid to attach to the inner side of the dura.
• There are 18-24 dentate ligaments throughout the length of the spinal cord.
• The first dentate ligament lies above the foramen magnum between the vertebral artery and the spinal root of the accessory nerve (cranial nerve 11).

Blood Supply

• The spinal cord is supplied by branches of the vertebral and segmental arteries.
• The vertebral artery gives rise to anterior and posterior spinal arteries.

White Matter (Spinal Cord Tracts)

• The white matter of the spinal cord surrounds the grey matter and is made of axons.
• The bulk of the white matter is divided into three regions: anterior funiculus, posterior funiculus, and lateral funiculus.
• Each of these funiculi contains specific tracts.

Anterior Funiculus

• Ascending tract: anterior spinothalamic tract
• Descending tracts: anterior corticospinal tract, vestibulo-spinal tract, tecto-spinal tract, and reticulo-spinal tract

Lateral Funiculus

• Ascending tracts: posterior spinocerebellar tract, anterior spinocerebellar tract, lateral spinothalamic tract, and spino-tectal tract
• Descending tracts: lateral corticospinal tract, rubrospinal tract, and olivo-spinal tract

Posterior Funiculus

• Ascending tracts: gracile fasciculus and cuneate fasciculus

Spinal Nerves

• Spinal nerves are grouped in correspondence to the cord segments as: Cervical (C1-C8), Thoracic (T1-T12), Lumbar (L1-L5), Sacral (S1-S5), and Coccygeal (Co1).
• There are a total of 31 pairs of spinal nerves.

Cross Section

• The spinal cord has four surfaces: anterior, posterior, and two lateral surfaces.
• There are specific grooves that can be seen on these cord surfaces, including fissures and sulci.

Grey Matter

• The grey matter is the butterfly-shaped (H-shaped) central part of the spinal cord.
• It is comprised of neuronal cell bodies and is divided into anterior, posterior, and lateral horns (regions).
• The anterior (ventral) horn contains the cell bodies from which the axons of the anterior roots of the spinal nerves exit the cord.