Autonomic Nervous System Flashcards
What is the main function of the autonomic nervous system?
involuntary control of smooth and cardiac muscles + glands
What are the major differences between the somatic and autonomic nervous system?
effectors: somatic - skeletal muscle, ANS - smooth, cardiac, and glands
efferent pathway: somatic - single, heavily myelinated axon that extends from CNS to effector
Efferent pathway:
ANS - 2 neuron chain and synapses at ganglion peripheral to CNS
pregang - lightly myelinated axon vs postgang - unmyelinated axon that extends to effector
Target Organ responses to Neurotransmitters:
pregang = ACh and post gang = NE (sympa) and parasympa = ACh
effect is excitatory or inhibitory based on neurotransmitter and receptor on organ
Which neurotransmitters are pregang and postgang?
Pregang is always Ach, post-sympa is NE(norepinephrine) and post-parasympa is always ACh
How does the nervous system regulate: the heart, stomach, and bronchi?
Heart: Sympa + and Para -
Stomach: Sympa - and Para +
Bronchi: Sympa + (relax) and Para -
How does the nervous system regulate: Gallbladder/Liver, Bladder, Rectum
Gallbladder/Liver:
Sympa - stimulates glucose from liver and NE secretion E from kidney
Para - stimulates gallbladder
Bladder: sympa - relaxes and Para contracts
Rectum: sympa - contracts rectum and Para relaxes
How does the anatomy of para and sympa differ in: site of origin, length of fibers, location of ganglia
site of origin: para - craniosacral and sympa - thoracolumbar
length: sympa - long and para - short
location: sympa - close to spinal cord (lateral) and para - close to organs
What are the general functions of the sympathetic division?
diffuse action to multiple body organs
one nerve can split and innervate many
one pregang can synapse with many post-gang
sympa stimulation of adrenal medulla can innervate many organs with NE and E from kidneys
What is the general function of the parasympathetic division?
gang located in or around target organs
ratio of pregang to postgang is smaller than sympa
no equivalent to adrenal release
What is the sympathetic trunk?
allows nerves fibers to travel to spinal nerves inferiorly and superiorly from base of skull to coccyx
In the sympathetic Division pathway, what’s the difference between motor and nerve in function/location?
ventral efferent (motor) and dorsal afferent (nerve)
What is the difference between the efferent pathways: somatic vs autonomic?
efferent pathway: somatic - single, heavily myelinated axon that extends from CNS to effector
Efferent pathway:
ANS - 2 neuron chain and synapses at ganglion peripheral to CNS
pregang - lightly myelinated axon vs postgang - unmyelinated axon that extends to effector
