Autonomous Nervous System Flashcards
Where does smooth muscle come from?
From the splanchnic/visceral layer of lateral mesoderm.
What is the main difference between the somatic and the autonomous nervous system?
Somatic - 1 motor nueron
Autonomic - 2 motor neurons
Where are sympathetic preganglionic visceromotor nuerons located?
At the lateral horn / intermediolateral.
T1 to L2
In lenght how are the preganglionic and postganglionic fibers in the sympathetic system?
Preganglionic fibers are short
Postganglionic are long.
What is the motto of the sympathetic system?
Fight or Flight
What does the sympathetic trunk/chain innervate?
The dermis (sweat glands, arrector pili muscle and blood vessels) and the Thoracic visera (lungs, heart…).
What does the preaortic single ganglia innervate?
The abdominal and pelvic cavities.
What is innervated ONLY by the sympathetic smooth muscle?
The dermal smooth muscle (blood vessels, arrector pili muscle and sweat glands).
With what type of nerves go the sympathetic nerves that are going to innervate the smooth muscle?
With the spinal nerves.
What do the postganglionic fibers that innervate the Thoracic Viscera form?
The Cardiac Nerves
What type of nerves form the preganglionic nerves that innervate the abdominal cavities?
Splanchnic Nerves
In lenght how are the preganglionic and postganglionic fibers in the parasympathetic system?
Preganglionic fibers are long.
Postganglionic fibers are short.
What do the nerves of the parasympathetic system from the brainstem innervate?
The thoracic and abdominal viscera (2/3 of TC).
What do the the nerves of the parasympathetic system from S2-S4 innervate?
The rest of the GI tract and the pelvic viscera.
With what fibers does pain travel with?
With sympathetic fibers and reach the CNS first through the white communicating rami and then through the dorsal root (propia de las sensory fibers).
What type of pain travels with the PS system?
Pelvic Pain
Whith what fibers does distention travel with?
With Parasympathetic fibers. Enter the CNS at the brainstem and sacral level.
What nerve follows the distention info from the the thoracic, abdominal and the distal third of the TC?
The Vagus Nerve
With what nerve travels the distention info. from pelvic viscera?
With the pelvic splanchnic nerves.
What do all preganglionic fibers release?
All release Acetylcholine (Ach).
What will the second neurotransmitter released in the sympathetic system?
Which is the exception?
NorEpinephrine or Epinephrine (Adrenaline)
Glands and Blood Vessels in Skeletal Muscle release Ach.
What gland releases Adrenaline directly into the blood?
Adrenal Glands/Medulla
Innervated by Preganglionic Sympathetic Neurons
What releases the postganglionic fiber of the parasympathetic system?
Ach
Which is the mechanism of Muscarinic and Nicotinic receptors for Ach?
Two different mechanisms
Muscarinic - G protein mechanism
Nicotinic - Ligand gated ion channels
Which is the mechanism of Adrenergic receptors?
Alpha and Beta are both G protein coupled
Which Adrenergic Receptor is in charge of the heart?
Beta 1
Which Adrenergic Receptor is in charge of Bronchial, bladder…?
Beta 2
Which is the predominant tone in the heart?
The parasympathetic tone.
Which is the predominant tone in the blood vessels?
The Sympathetic Tone
Normally, the blood vessels are contracted.
Which type of receptor is present in the heart?
Beta 1
Which type of receptor is present in the vascular smooth muscles?
Alpha 1
