Autonomic Nervous System Flashcards
Afferent neurons of the ANS respond to what stimuli?
Stretch, Glucose, PCO2, PO2, Osmolarity and pH, Temperature
What are the cells involved in a typical sympathetic nervous system pathway?
Preganglionic neuron, postganglionic neuron, target cell
What kind of neuron is the preganglionic neuron in a typical sympathetic nervous pathway? The postganglionic?
Cholinergic; Adrenergic
To what kind of cholinergic receptor will ACh bind on the postganglionic neuron in the sympathtic nervous system?
Nicotinic (N2); muscarinic at some sweat glands and vessels
To what kind of receptor will norepinephrine bind on the target cell?
Alpha- or beta- adrenergic receptors
What events occur upon binding of NE to an adrenergic receptor with an alpha-q subunit?
Phospholipase C converts PIP2 to IP3 and DAG; IP3 increases Ca++ cpncentration in the cytosol
The binding of NE to a receptor with what kind of alpha subunit will result in inhibition of adenylyl cyclase activity?
Alpha I
What events occur upon binding of NE to an adrenergic receptor with an alpha-s subunit?
Increased adenylyl cyclase activity and increased cAMP concentration
Where are adrenergic receptors with alpha-s subunits found?
Heart, smooth muscle and adipose muscle
What kind of neuron is the preganglionicneuron in a typical parasympathetic nervous pathway? The postsympathetic?
Cholinergic; Cholinergic
To what kind of receptor will ACh released by a parasympathetic postsynaptic neroun bind on the target cell?
Muscarinic receptor
What type of cholinergic receptor is a GPCR?
Muscarinic receptors
What are the 2 networks of the enteric nervous system? What do they each control
Myenteric (motility) and Submucosal(secretion)
What kind of neurons connect the motor and sensory components of the enteric nervous system?
Interneurons
What is the main neurotransmitter utilized by the enteric nervous system?
Acetylcholine
What are the functions of the enteric nervous system?
Monitors contents, coordinates functions and responds to changes in GI tract; monitors the stage of the lumen and gut wall; responds by activating intrinsic reflex
What neurotransmitter is antagonistic to ACh in the enteric nervous system?
Norepinephrine
What tissues receive solely SNS innervation?
Adrenal medulla, sweat glands, erector pili muscles, kidneys, blood vessels
What physiologic events occur during the fight or flight response?
Dilation of pupils, increase in heart rate bloop pressure and respiratory rate, decreased bloop floow to nonessential areas,, increased blood flow to essential organs, increased bronchodilation, increased respiratory rate, increased fuel mobilization
What is the SLUDD response? Which ANS system is it associated with?
Salivation, Lacrimation, Urinatinon, Digestion, Defectation; Parasympathetics
Where are baroreceptors located?
The carotid, aortic arch, right heart and pulmonary vessels
What is the autonomic nervous system response to low blood pressure? What physiologic events occur?
SNS activity increase, PSNS activity decrease; Increases BP and HR
How does the parasympathetic nervous system increase digestive proceses?
Increasing gut motility, sphicter relaxation, and acid/ enzyme secretion
What ANS nervous system has exclusive modulation over thermoregulation?
Sympathetics
What is the physiologic response to decreased temperature?
Shivering, piloerection, skin vasoconstriction, decreased sweating
What neurotramsitters mediate vasodilation of penile blood vessels by the parasympathetic nervous system?
ACh and Nitric Oxide
