Lecture 8 Flashcards
autonomic nervous system is stimulated by centers located in the _____,_____,______, and ________
spinal cord
brainstem
hypothalamus
portions of the cerebral cortex
the autonomic nervous system often operates by means of ______, which involves ________
visceral reflexes
subconscious sensory signals from visceral organs
in the autonomic nervous system, these visceral reflex loops can return an ______reflex motor response back to the visceral organ to control _____
involuntary
its activity
two major subdivisions of autonomic nervous system
sympathetic NS
parasympathetic NS
most organs receive intervention from _____NS
both sympathetic and parasympathetic
the autonomic NS receives input from the brainstem. this input including _____________________.
brainstem
-arterial pressure
-heart rate
-respiratory rate
the ______ and _____ also play a large role in regulating the activity of the autonomic NS
hypothalamus
cerebral cortex
parasympathetic located in the ______ and sympathetic in the _______
anterior of hypothalamus
posterior of hypothalamus
skeletal muscle stimulation requires _____ impulses per second to fire a muscle.
in contrast, the ANS only requires ___ impulses every ______.
Full activation of either Sympathetic or parasympathetic require _____ per second
50-500
1 every few seconds
10-20
autonomic tone
not a lot of impulses needed to activate
the sympathetic nervous system has the capability to simultaneously ______
dilate some arterioles and constrict others
what are some important nerves in the ANS
the vagus nerve (cranial nerve X)
role of the vagus nerve
important parasympathetic ton activity : GI peristalsis
cutting almost any sympathetic nerve to a specific organ will often result in significant ______ in less than ______ to that organ. this is how we know ____ muscle has some ability to control itself
vasodilation
less than a minute
smooth muscle
what is secreted into the bloodstream at all times to provide a baseline tone?
- epinephrine (0.2 mcg/kg/min)
- norepinephrine (0.05 mcg/kg/min)
what makes and secretes epinephrine and norepinephrine?
adrenal medulla
- adrenal gland is on top of kidneys
the baseline tone allows ______ to remain at normal levels even without direct ________ nerve activity
blood pressure
sympathetic
sensitivity to norepinephrine and ________ is unregulated after a ______ event, or trauma, causing super sensitivity. the response of _____ is magnified
acetylcholine
denervation
vasoconstriction
Within _______ seconds, HR can be doubled by the ANS
Within _______ seconds, Arterial Pressure can be doubled, or it can be lowered enough to cause ______
Sweating can begin within seconds
3-5 seconds
10-15 seconds
syncope
Stretch sensors in the bladder causes signals to be sent to the __________, which causes the bladder to contract, and the __________ to relax
Voluntary control may need to be exerted to prevent this.
sacral spinal cord
urinary sphincters
________ can send signals up, down, or out to the organs. to is located ______. this involves _____ synapse
sympathetic trunk ganglia
slightly in front of spinal cord on the sides
chemical
sympathetic NS’s general peripheral organization contains ___________ sympathetic ganglia that are interconnected with spinal nerves on each Side of the cord (bilateral)
2 paravertebral chains of ganglia
each paravertebral ganglia consist of _ ________
3 prevertebral ganglia
the 3 prevertebral ganglia lie ____ to the vertebral column and close to __________
anterior
large abdominal arteries