20.9 Flashcards
(15 cards)
The sympathetic nervous system is ___-___ (cranial/cervical/thoracic/lumbar/sacral?).
Thoraco-lumbar.
Start in thoracic and lumbar spinal cord.
The parasympathetic nervous system is ___-___ (cranial/cervical/thoracic/lumbar/sacral?).
Cranio-sacral.
Some nuclei in cranial system/brainstem, or from sacral spinal cord.
NO autonomic pathways start in the ___ cord or ___ enlargement.
Cervical cord or lumbar enlargement.
The more rostral the pathway starts, the more ___ the organ innervated (and v.v.).
Rostral
Sympathetic preganglionic neurons are ALL located in the ___-___ cord, from the intermediolateral cell column (T___ - L___).
Thoraco-lumbar cord.
From the intermediolateral cell column (T1 to L3).
Axons from SNS exit the cord via ___ roots (with ___ neurons) to sympathetic ganglia.
Ventral roots with motor neurons
Connections of symp. preganglionic neurons:
Sympathetic postganglionic neurons are in two types of ganglia:
Paravertebral ganglia (sympathetic chain) - primary source of vasoconstrictor neurons.
Prevertebral ganglia - primary source of neurons innervating non-vascular smooth muscle.
Note - preganglionic neurons also innervate the adrenal medulla - the sympathoadrenal system for release of NAd and Ad.
Parasympathetic preganglionic neurons are located in ___ or ___ spinal cord.
What are the nuclei in the brain stem, and from what levels of the spinal cord?
Brainstem or sacral spinal cord.
Brain stem nuclei:
- Edinger-Westphal nucleus - to ciliary ganglion to control sphincter pupillae and ciliary muscle.
- Salivatory nuclei - submandibular, sphenopalatine and otic ganglia.
- Dorsal motor nucleus of vagus and nucleus ambiguus - to microganglia.
Sacral spinal cord from intermediolateral cell column (S1 to S5).
Connections of parasymp. preganglionic neurons:
Sacral postganglionic neurons are in the ___ plexus i.e. the ___ ___ plexus.
Pelvic plexus, or inferior hypogastric plexus.
There are lots of sympathetic neurons in pelvic ganglia - i.e. mixed ganglia.
While the SNS and PNS use two fibre systems (pre and postganglionic fibres), the somatic motor system has no ___ in between. There is a neuron from the ___ ___ direct to muscle.
No ganglia in between
Neuron from spinal cord direct to muscle.
The major integrative centre for autonomic function is the ___ part of the ___ of ___ ___ (other names?) in the medulla! Second order neurons here receive input from ___ ___.
CAUDAL PART of nucleus of solitary tract (or nucleus tractus solitarius, or nucleus solitarus (remember - it was the nucleus for visceral afferents of CN 7/9/10)).
Receive input from VISCERAL AFFERENTS
The ___ (esp. the ___ nucleus of the ___) is most important for central coordination of autonomic output.
Hypothalamus esp. the paraventricular nucleus
The ___ compares information from sensory pathways, intrinsic sensory structures (e.g. osmoreceptors) and circulating hormones with set points.
Hypothalamus
Some autonomic reflexes occur ____ of the CNS.
Independently e.g. the enteric nervous system, gut does not depend on brain to start reflexes like peristalsis
Note that each SNS preganglionic neuron activates MANY ___ neurons -> causes mass activation and coordination, important for stress response.
Postganglionic
