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

2024
Views:

278

Pages:

3
Author:

Mariam A. A.

ANS ● ● ● ● ● ● Visceral motor system Not under conscious control by the brain Regulated by the hypothalamus and reticular formation of the brainstem Separate from the somatic NS In the medulla of the brainstem, nuclei will send the signal down the spinal cord to the particular nerves that will drive the action Major targets = visceral organs of thoracic and abdominal cavities including blood vessels, hairs and sweat glands ANS function ● Homeostasis ● Control of glands, cardiac and smooth muscle ● Regulation through parasympathetic (rest and relaxation) and sympathetic divisions (fight or flight that counteracts the parasympathetic) ● If they innervate both = have opposing roles ANS visceral reflex arc ● ● ● ● ● ● ● Reflex arc through the spinal cord Stimulus Receptor in the organ Sensory neuron goes into the spinal cord and to a specific part of the spinal cord (dorsal horn where the ANS nervous cells sit) Goes out through visceral efferent Goes to a ganglion (group of cell bodies in the PNS) where it synapses to another neuron which goes to the organ ANS is not instantaneous e.g. can take longer to digest food doesn’t need to happen straight away ANS plexuses ● NOT the same as somatic (lumbosacral/brachial) plexuses (because it joins para and sympathetic rather than joining of the different spinal levels) ● Mix para and sympathetic inputs to the same organ ● Mix fibres together and have a single nerve that goes to that organ with both para and sympathetic so that each organ receives both ● Sympathetic comes from the thoracolumbar region ● Para come from the brain through the vagus nerve and the sacrum ○ Thorax, lungs, heart and gastrointestinal system gets input from the vagus nerve Why is the site for CSF sampling and epidurals at the lumbar vertebrae? ● CSF is continuous throughout the vertebral region and there shouldn’t be any abnormalities with the CSF throughout ● Means that its circulating properly throughout the CNS ● ● ● ● ● ● ● ● Spinous process vertebral are short Able to get an open space to put the needle Spinous processes that were horizontal can be flexed Everything below is less likely to put the needle into the spinal cord itself Epidural = anaesthetic (this space has veins and adipose tissue but no CSF) Put in the lumbar region to numb the muscles down, only put the anaesthetic on the nerves that will innervate the region that you want to numb If you do it higher = will affect breathing How do lumbar punctures and epidurals differ in terms of the depth of the needle? ○ One takes something out = longer needle (need to get to the subarachnoid space) ○ One puts something in = upon the dura ○ Epidural means upon the dura = more superficial depth of the needle ○ Epidural just bathe the nerves in the anaesthetic Cross section of a spinal cord ● The dorsal root ganglion is on the dorsal side