sensitive neuron

Where are sensitive neurons mostly situated?

Posterior horns; form nuclei; axons form ascending tracts.

Posterior marginal nucleus (Waldeyer zone) – key features

Rexed lamina II; spongy aspect; axons enter substantia gelatinosa of Rolando.

Substantia gelatinosa of Rolando – key features

Rexed lamina II

well represented in cervical and lumbar regions

continues in medulla oblongata as nucleus of spinal tract of trigeminal nerve.

Nucleus proprius – key features

Rexed laminae III and IV; connections with substantia gelatinosa of Rolando.

Thoracic nucleus of Clarke – key features

Rexed lamina VII

dorsal intermediate substance (medial base of posterior horn)

receives unconscious proprioception from inferior limbs and lower trunk.

Visceral nucleus – key features

Rexed lamina VII

lateral to thoracic nucleus

dorsal to intermediolateral nucleus.

Lateral cervical nucleus – key features

Lateral horn near posterior cord

found at C1–C2.

Anterior and posterior commissural nuclei – location

Rexed lamina X.

Anterior commissural nucleus – location

Medial border of anterior horn of intermediate gray matter.

Posterior commissural nucleus – location

Posterior border of intermediate gray matter.

Where are efferent (motor) neurons found?

Anterior and lateral horns.

What do axons of efferent neurons form?

Ventral roots of spinal nerves.

Number of efferent neurons

About 80,000–160,000.

What nuclei do efferent neuron cell bodies form?

Visceromotor and somatomotor nuclei.