University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

388

Pages:

3
Author:

Mariam A.

Autonomic nervous system  Preganglionic neurons are located in the intermediolateral column of the sacral segments of the spinal cord; postganglionic neurons are located external to the spinal cord.  Not just motor (sympathetic or parasympathetic); there are afferent axons from the viscera that enter the spinal cord via the dorsal roots, or enter the brain via the cranial nerves. These also synapse on sympathetic (in the thoraco-lumbar segments) or parasympathetic (in the sacral segments) motor neurons and are engaged in spinal autonomic reflexes. Visceral sensory axons synapse on interneurons within the dorsal horn, which can activate sympathetic neurons.    o In spinal cord injury, this spinal reflex can lead to dramatic increases in sympathetic vasoconstriction. o Resultant increase in arterial pressure can lead to autonomic dysreflexia. Somatic afferents also synapse on interneurons within the dorsal horn, which can activate sympathetic neurons within the intermediolateral horn. o Can also lead to autonomic dysreflexia. Conclusions  Interneurons and motoneurons are located within the grey matter of the ventral horn.  Preganglionic sympathetic and parasympathetic neurons are located in the intermediolateral horn of the spinal cord.  Somatosensory system includes specialised stretch receptors in the muscle – the muscle spindles – which are unique in having their own motor innervation.   Muscle spindles are muscle length receptors. Golgi tendon organs, located in series with muscles, sense active muscle force.