Exploration of the spinal cord and meninges in situ
Cervical spinal cord; denticulate ligaments
The arachnoid membrane has been cut away. Between nearly every group of cervical posterior roots small accessory filaments appear, such as the one seen at 17. This one divides and contributes fibers to two cervical nerves. In other instances, however, two filaments from neighboring posterior roots (e.g., right 4th and 5th roots) join to form a single strand which then passes out with one of the nerves. These filaments were not present in lower parts of the spinal cord.
Cerebellar tonsil
Medulla oblongata
Margin of foramen magnum
Vertebral artery and posterior inferior cerebellar artery
Suboccipital nerve
Posterior arch of atlas (cut across)
Dorsal root cervical nerve II
Inferior oblique capitis muscle
Greater occipital nerve
Third occipital nerve
Muscular branch of cervical nerve III
Splenius capitis muscle
Posterior median sulcus
Posterior intermedian sulcus
Posterior lateral sulcus
Dorsal root cervical nerve VI
Accessory filament of posterior root which bifurcates