Flashcards in ANS 2 Deck (23)
1. low BP leads to relative increase in sympathetic output
2. High BP leads to relative increase in parasympathetic output
Humoral response to low blood pressure: controlled by?
release of hormones via the pituitary
vasoconstriction, which acts on kidneys to increase water retention
where is vasopressin released from
Low blood pressure causes ____ to be releases from kidneys
what does renin do?
activates angiotensiongen (from liver) to angiotensin I, which can be activated to angiotensin II
angiotensin II functions
1. constricts blood vessels
2. acts on kidney to increase water retention
3. activated neurons in subfornical organ
Opposing effects of _____ enable homeostasis
sympathetic and parasympathetic divisions
____ coordinates ANS and humoral responses
the preganglionic neurons of the parasympathetic nervous system are located in ___
brainstem nuclei and in the sacral spinal cord.
Parasympathetic preganglionic neurons are characterized by?
long axons, use acetylcholine as a neurotransmitter, and innervate postganglionic neurons located in ganglia near or in the effector organ.
The parasympathetic, preganglionic fibers exit the brainstem in?
cranial nerves III (oculomotor), VII (facial), IX (glossopharyngeal), and X (vagus).
The parasympathetic, postganglionic neurons
1. use acetylcholine as a neurotransmitter.
2. Due to their location in or near the effector organ, they are characterized by short axons.
The axons from the preganglionic neurons in the sacral portion of the parasympathetic system travel in the?
splanchnic nerves to innervate ganglia associated with the colon, rectum, urinary bladder, and genital organs.
This portion of the system functions to control "emptying", e.g. urination, defecation, and erection.
Increased parasympathetic output results in?
decreased heart rate and force of contraction.
parasympathetic output may result in some small amount of
but most vasodilation is controlled by decreased sympathetic output.
There are two types of cholinergic receptors to which ACh binds and elicits a cholinergic response?
1. nicotinic (stimulated by nicotine)
2. muscarinic (stimulated by muscarine)
nicotinic receptors are present in the?
cell body of postganglionic neurons of the autonomic ganglia
muscarinic receptors are present on the ?
effector cells of cardiac muscle, smooth muscle, and glands
The nicotinic receptor is a?
ligand-gated, non-selective cation channel.
α1 CV related action of agonist
vasoconstriction in skin