Synonyms
Medical: Substantia alba spinalis CNS, spinal cord, spinal nerve tract, brain, nerve cell, spinal ganglia, gray matter spinal cord
Introduction
This text tries to present the very complex interrelationships in the spinal cord in an understandable way. Due to the complexity of the topic it is aimed at medical students, doctors and very interested laymen.
Declaration
Tractus spinothalamicus anterior and lateralis (dorsal thalamic pathways) These two pathways are located in the anterior strand of the white spinal cord substance. They lead first from the spinal ganglion to the not very distant strand cells in the posterior horn of the spinal cord. The strand cells thus form the second neuron of this pathway. This neuron then sends its extensions to the thalamus as a long, ascending (afferent) pathway – this long pathway is the actual tractus, i.e. “train” – and short connections to segments located somewhat further down, which are involved in reflex mechanisms. 1 + 2 Spinal cord – Medulla spinalis
- Grey spinal cord substance – Substantia grisea
- White spinal cord substance – Substantia alba
- Anterior root – Radix anterior
- Posterior root – Radix posterior
- Spinal ganglion – Ganglion sensorium
- Spinal nerve – N. spinalis
- Periosteum – periosteum
- Epidural space – Spatium epidurale
- Hard spinal cord skin – Dura mater spinalis
- Subdural cleft -Spatium subdural
- Cobweb skin – Arachnoidea mater spinalis
- Cerebral fluid space – Spatium subarachnoideum
- Spinous process – Processus spinosus
- Vertebral bodies – Foramen vertebrale
- Transverse process – Processus costiformis
- Transverse process hole – Foramen transversarium
Function
The long ascending fibers, in contrast to the rear strand, already change to the opposite side here: they cross in the so-called commissura alba of the spinal cord. This ultimately means that if the spinal cord is damaged on the left side, the right half of the body is affected by the loss of function. In the case of the dorsal thalamic tract (tractus spinothalamicus), this is the sensation of pain, temperature and coarse pressure (in the sense of bruising, etc.
), which is collectively referred to as protopathic sensitivity. The lateral (lateral) of the two tracts preferentially conducts the pain and temperature stimuli and the anterior (anterior) coarse touch and pressure stimuli. In the medulla oblongata, the two pathways are attached to each other and run together via the thalamus, which contains the third neuron, to the cerebral cortex (more precisely: to the postcentral gyrus), where conscious perception takes place.
Here lies the 4th and last neuron. The “pain pathway”, the tractus spinothalamicus lateralis, obtains the information it transmits to the brain from small cells in the spinal ganglion, whose leading extensions (dendrites) are located in the skin and mucous membranes as specialized sensory cells, so-called nociceptors. Of the pain-conducting fibers there are slow (C-fibers) and fast (A-δ fibers).
- Dendrites
- Cell Body
- Axon
- Nucleus
There are direct contacts from the ascending tract to nucleus groups distributed in the brain stem, which are known as Formatio reticularis (= (“net-like formations”) due to their distribution. These connections lead to increased alertness and alertness level and to stimulation of the cardiovascular and respiratory systems. The body signals us in this way: Man, watch out – please avoid further tissue damage! Further connections into the limbic system, which is responsible for emotional evaluation, ensure that we remember the hot stove as negative.
