Autonomic Nervous System Flashcards
ANS overview
contains:
- motor neurons that control internal organs automatically
- sensory neurons from internal organs (whose cell bodies are in the DRG with somatic sensory neurons)
- 2 divisions
divisions of ANS
- sympathetic
- parasymphathetic
–> have opposite effects on the same organs
sympathetic NS overview
- aka thoracolumbar division
- important during emergency situations (fight or flight response)
- widespread targets
- purpose = to increase oxygen and glucose available for active muscular contraction
sympathetic NS influence on body
- increases heart rt + breathing rt
- dilates bronchi
- makes liver break down glucagon into blood glucose
- inhibits digestion (not urgent –> conserves energy)
neurotransmitter of sympathetic NS
norepinephrine
ganglia of sympathetic nervous system (4)
- sympathetic trunk ganglia
- celiac ganglion
- superiomesenteric ganglion
- inferior mesenteric ganglion
sympathetic trunk ganglia
- part of sympathetic NS
- located on both sides of spinal cord
- innervate effector organs in trunk/head/limbs
celiac ganglion
- largest ganglion of sympathetic NS
- innervates digestive tract
superiomesenteric ganglion
innervates small intestine and part of large intestine
inferior mesenteric ganglion
innervates large intestine, kidneys, bladder, sex organs
parasympathetic NS (in depth)
- aka craniosacral division, “housekeeper system”
- more specific targets than sympathetic NS
- promotes all internal responses of relaxed state
parasympathetic NS influence on body
- constricts pupil, helps lenses focus on nearby objects
- promotes digestion (stimulates gi tract muscles and digestive glands)
- slows heart rt
parasympathetic NS neurotransmitter
acetylcholine (ACh)
ganglia of parasympathetic NS (5)
- ciliary ganglion
- pterygopalatine ganglion
- submandibular ganglion
- otic ganglion
- intramural ganglia
ciliary ganglion
- part of parasympathetic NS
- associated with CN III
- targets intrinsic eye muscles to change pupil/lens
pterygopalatine ganglion
- part of parasympathetic NS
- associated with CN VII
- targets tear productions, nasal + salivary glands
submandibular ganglion
- part of parasympathetic NS
- associated with CN VII
- targets tear production, nasal + salivary glands
otic ganglion
- part of parasympathetic NS
- associated with CN IX
- targets parotid glands
intramural ganglia
- part of parasympathetic NS
- associated with CN X
- targets visceral organs of thoracic cavity
Preganglionic axon
motor neuron w/ cell body in spinal cord whose axon synapses on motor neuron outside spinal cord in an autonomic ganglion
postganglionic axon
axon of ganglionic neuron (located in autonomic ganglion) whose axon synapses on an effector organ in PNS
