Week 11 - Autonomic Nervous System (Parasympathetic and Sympathetic) Flashcards
What are the two divisions of the autonomic nervous sytem (ANS)?
parasympathetic and sympathetic
(enteric)
What does the ANS do?
responds to physiological demands without you being aware of it (involuntary)
What is the peripheral nervous system?
part of the nervous sytem that consists of all the neurons and ganglia outside of the brain and spinal cord
includes the somatic and autonomic nervous systems
What is the difference between the ANS and the SNS?
SNS is voluntary
ANS is involuntary
Which division of the ANS has short pre-ganglionic neurons?
sympathetic
Which division of the ANS has short postganglionic fibres?
parasympathetic
What receptor does acetylcholine activate on postganglionic fibres of the sympathetic nervous system?
nicotine acetylcholine receptors
What susbstance do postganglionic fibres of the sympathetic nervous system release when activated?
norepinephrine/noradrenaline
What receptors are activated on the peripheral target tissues when noradrenaline is released by postganglionic fibres of the sympathetic nervous system?
adrenergic receptors
What are the two exceptions of postganglionic cells of the symathetic nervous system?
sweat glands - release ACh
chromaffin cells of the adrenal medulla - noradrenaline is released directly into the blood (no postganglionic neurone)
What receptos are activated on peripheral target tissues when ACh is released by postganglionic neurones of the parasympathetic nervous system?
muscarinic acetylcholine receptors
What division of the ANS is described as having cranio-sacral outflow?
parasympathetic
the location of the preganglionic neuron cell bodies are
- cranial
- sacral spinal cord S2-S4
What are the four cranial nerves that are part of the PN?
oculomotor
facial
glossopharyngeal
vagus
At what vertebral level do the pelvic splanchnic nerves arise from?
S2-S4
What kind of outflow does the sympathetic nervous system have and what spinal cord segments does this arise from?
thoraco-lumbar outflow
T1 - L2
What is the alternative name for the submucosal plexus?
meissner plexus
myenteric - Auerbach plexus
What are exteroreceptive nerve endings?
superficially located nerve endings that respond to stimuli for pain, temperature and pressure
What are proprioceptive nerve endings?
nerve endings in muscles, tendons and joints that provide data for reflex adjustments of muscle action and for awareness of position and movement
Where are preganglionic parasympathetic neurons located?
CN III, VII, IX, X
S2-S4
What does the term visceral mean in neurobiology?
all the innervated smooth and cardiac muscle
innervation of secretory cells in all parts of the body
How does the efferent supply of smooth muscle cells differ from skeletal muscle cells?
somatic - connection between CNS and skeletal muscle consists of a single motor neuron
autonomic - succession of at least two neurons between CNS and smooth muscle
Give an example of where a noncholinergenic and nonadrenergic receptor might be found
in blood vessels, releases NO to cause dilation
What enzyme breaks down acetylcholine to terminate the action potential?
acetylcholinesterase
Where do the preganglionic axons of the sympathetic nervous system exit the spinal cord?
in the ventral nerve roots
