AUTONOMIC NERVOUS SYSTEM Flashcards
what are the two functional divisions of the NS
Somatic part Visceral part (autonomic)
what does the somatic part innervate
skin and skeletal muscles
Peripheral distribution of the somatic NS is done by
spinal and cranial nerves
In the somatic part of the NS peripheral how many neurons typically connect the CNS with the organ
1
the somatic part of the NS is mainly involved in…
receiving impulses from external environment and responding accordingly
what does the visceral part of the NS innervate
internal organ sysetms, smooth muscles, and glandular tissues
the visceral (autonomic) part of the NS is mainly involved in…
receiving information from internal milieu and initiating appropriate response (homeostasis)
What is the peripheral distribution of the autonomic NS done by
sympathetic & parasympatheric system
How many neurons are there between the CNS and the target organ in the automic NS
2 neurons
3 characteristics of the sympathetic NS
- Fight or flight
- Catabolic
- mobilize energy stores
3 characteristics of the parasympathetic NS
- Rest and repose
- Anabolic
- Growth, tissue repair/maintenance
Sympathetic fibres arise from
lateral horn of the spinal at level of T1-L2 spinal segments
What are the two possible routes of the fibres of the sympathetic system
- Synapse at the para-vertebral ganglia and distribute to the thorax, head, & neck and limbs
- Bypass the para-vertebral ganglia, form the splanchnic nerves, synapse in pre-vertebral ganglia in the abdomen and supply the abdominal and pelvis organs
parasympathetic fibres arise from…
either the nuclei in brainstem or from lateral horn of the spinal cord at the level of S2–S4 spinal segments
The parasympathetic fibers arising from brainstem are distributed via ____
cranial nerves
What do the parasympathetic fibres arising from the brainstem supply
the head & neck and thorax, and most of the abdominal viscera down to left 1/3 of transverse colon
What do the parasympathetic fibers originating from the spinal cord supply
the remaining abdominal viscera and all of pelvic viscera
All parasympathetic fibers syynapse at a ….
visceral ganglia prior to supplying the target organ
Do parasympathetic fibres supply limbs?
no
Where are the 2 centers of the parasympathetic system
- brainstem
2. in lateral hornal of spinal cord segments S2-S4
where are the paravertebral ganglia? what occurs at tem
on either side of vertebral column
Some sympathetic fibres will choose to synapse here activaating secondary neurons
How does nerve impulse get from the para-vertebral ganglia to the target organ
postganglionic fibres
What occurs to the preganglionic fibres that bypass the paravertebral ganglion
head to the prevertebral ganglia
Where do you fing the pre-verteberal ganglia
in the abdomen
What are the sympathetic fibres which fail to synapse in the paravertebral ganglion called
splanchnic
What do splanchnic nerves supply
the pelvic and abdominal viscera. NOT thorax
In what spinal segments is a lateral horn present
in T1-L2 segments
What does lateral horn contain
sympathetic neurons
Where is the main center for sympathetic neurons in the body
lateral horns of T1-L2 segments
Which cranial nerves distribute parasympathetic fibres
3,7,9,10
All ganglion in the sympathetic system are located very closely to…
the target organ
What are two similarities of the sympathetic and parasympathetic systems
Similar in structure
- They both have ganglia
- Neither will directly reach an organ - must synapse in a ganglion first
what are 3 differences between the sympathetic and parasympathetic systems
- Sympathetic fibres can only synapse in either para-vertebral of pre-vertebral
- Parasympathetic fibres can only synapse in visceral ganglia
- Para-sympathetic system has longer preganglionic fibres and shorter post-ganglionic fibres
