Autonomic Nervous System Flashcards
What are the three types of autonomic ganglia in the body?
Sympathetic chain - located in sympathetic trunk
Prevertebral (Preaortic) - Located anterior to the lumbar vertebrae and abdominal aorta
Terminal Ganglia - located in the wall of an organ or adjacent to the organ
Where are the pre- and postganglionic neuronal cell bodies of the sympathetic system and what are its functions?
Preganglionic- lateral horns of spinal cord grey matter in the thoracolumbar region
Postganglionic - sympthatic chain
Readies body for stressful or emergency situations
Where are the pre- and postganglionic neuronal cell bodies of the parasympathetic system and what are its functions?
Preganglionic - CN nuclei 3,7,9,10 and sacral spinal cord
Postganglionic - Terminal ganglia
Activities that restore body resources and conserve energy (usually opposite of sympathetic functions)
What three structures are only innervated by sympathetics?
Sweat glands
Medulla of adrenal gland
Arrector pili muscle
*Dual innervation of mostly everything else
What organs are innervated by the vagus nerve?
All thoracic viscera and most of the guy
What organs are innervated by the sacral component of the parasympathetic system?
Distal part of the large bowel and urinary bladder
Travel there via the pelvic splanchnic nerve
What is the white rami communicans?
Structure through which preganglionic sympathetic axons leave the ventral rami of the thoracolumbar spinal cord
15 pairs
What are the two possible targets for preganglionic cell axons of the sympathetic system?
Postganglionic neuronal cell body at the same spinal level in the sympathetic chain
Or they can travel caudal or rostral in the sympathetic chain to synapse at a different spinal level
What is the structure and path of the postganglionic neuron in the sympathetic system?
Unmyelinated axon
Courses into a gray ramus communicans which joins the ventral ramus of a spinal nerve and travels to peripheral cutaneous structures
What are two ways cervical and upper thoracic sympathetic chain ganglia can reach their targets?
Form cardiac and pulmonary nerves that descend the neck into the thorax and innervate their respective organs
Leave cervical ganglia and form perivascular plexus on branches of carotid arteries to reach structures in the head and neck
What are the splanchnic nerves?
Sympathetic nerves (except for pelvic) that innervate preaortic ganglia located around the roots of the major arteries that branch from the abdominal aorta
What is the path of postganglionic fibers leaving the preaortic ganglia?
Form a perivascular plexus on the arterial branches of the aorta and are distributed to the abdominal-pelvic viscera
What is the pathway of visceral pain afferents?
Cell bodies located in dorsal root ganglia
Peripheral processes leave ventral rami via white rami communicans and enter sympathetic trunk
Continue traveling (without synapsing) through cardiac, pulmonary, and splanchnic nerves to innervate the viscera
Central processes innervate neurons in dorsal horn
