Spinal cord - structure of gray and white matter, cross section (draw scheme)

The spinal cord runs through the spinal canal, it stretches for levels C1-L1 (epiconus). Its main functions are to relay sensory information from the body to the brain and motor information to the body to coordinate voluntary and involuntary movements. In addition, it plays a big part in controlling reflexes and autonomic functions of the body.

The spinal cord is divided into spinal segments. There are a total of 31 pairs of nerves; 8 cervical, 12 thoracic, 5 lumbar, and 1 coccygeal.

Structure of the spinal cord

White matter

Consists of myelinated neuron fibers (axons). The main parts are; Anterior, posterior, and lateral funiculus, anterior commissure, anterior media fissure and Posterior median sulcus.

• Anterior funiculus is located between the anterior median fissure and the anterolateral sulcus
• Lateral funiculus is located between the anterolateral and posterolateral sulci
• Posterior funiculus is located between the posterior median sulcus and the posterolateral sulci.

The posterior funiculus is divided by the posterior intermediate sulcus forming the gracile fasciculus for sensory information from the lower half of the body and the cuneate fasciculus from the upper half.

All the funiculus contain motor and sensory tracts that run upwards and downwards.

Motor and descending tracts (efferent) include the Pyramidal tracts

1. Lateral corticospinal tract
2. Anterior corticospinal tract

And the Extrapyramidal tracts:

1. Rubrospinal tract
2. Reticulospinal tracts
3. Olivospinal tracts
4. Vestibulospinal tracts

Sensory and ascending tracts (afferent) include the Dorsal column medial lemniscus system

1. Gracile Fasciculus
2. Cuneate fasciculus

Spinocerebellar tracts

1. Posterior spinocerebellar tract
2. Anterior spinocerebellar tract

Anterolateral System

1. Lateral spinothalamic tract
2. Anterior spinothalamic tract

And Spino-olivary fibers

Gray matter

Consists of neuronal cell bodies, neuropil (dendrites of unmyelinated axons), and glial cells. The main parts include the anterior, lateral, and posterior horn, intermediate column, and central zone

• Anterior horn contains somatomotor neurons (alpha + gamma): that transmit signals from the brain to the skeletal muscles for voluntary movements.

• Lateral horn contains visceromotor neurons (autonomic motor neurons): innervates smooth, cardiac muscle and glands of the internal organs. Regulate body functions such as heart rate, respiration, and secretions.

• Posterior horn contains somatosensory neurons: Transmits mechanical, thermal, and chemical external signals from the body to the CNS such as pain, temperature, touch, proprioception etc.

• Intermediate column contains viscerosensory neurons and transmits signals from the internal organs to the CNS.

https://www.wikiskripta.eu/w/Medulla_spinalis#Anatomie_m%C3%ADchy