Flashcards in PHARM A29: Introduction to Autonomics Deck (20):
What is the myelination status of autonomic nervous system nerves?
The preganglionic fiber is myelinated, while the postganglionic fiber is not
What is the sole criteria for distinguishing the sympathetic from the parasympathetic nervous system?
Location of the preganglionic cell body: SNS cell bodies are located in the thoracolumbar region and PSNS bodies are located in the cranial and sacral regions
What is the myelination status of motor nerves?
Are the preganglionic or postganglionic nerves longer in the SNS? In the PSNS?
In the SNS the postganglionic fibers are longer; in the PSNS the preganglionic fibers are longer
True or False: Sympathetic preganglionic fibers can activate multiple postganglionic fibers to create a diffuse response
Through what structure do sympathetic nerve fibers reach the sympathetic chain?
Following the entry of a SNS fiber into the sympathetic chain, what are the three routes that can be taken?
The fiber can 1) synapse at the same spinal cord level 2) ove up or down the chain to synapse at another spinal cord level or 3) exit the chain without synapsing and synapse on prevertebral ganglia
Through what structure can preganglionic SNS fibers exit the sympathetic chain?
What is the relative affinity of ACh for the nicotinic and muscarinic receptors?
Where are nicotinic cholinergic receptors found? Muscarinic?
At autonomic ganglia on postganglionic cell bodies and skeletal muscle ; some end/ target organs
What is the relative affinity of norepinephrine to alpha 1 and 2 and beta 1 adrenergic receptors? What is the relative threshold for activation by NE among the three?
Equal; B1 has a lower threshold than A1 and 2
What neurotransmitters are used at SNS and PSNS synapses?
PSNS- both synapses use ACh; SNS- preganglionic fiber is cholinergic, and post is adrenergic (except cholinergic going to sweat glands)
What is the difference between a junctional and extrajunctional receptor?
Junctional receptors are located very near nerve terminals, while extrajunctional receptors are not and so they require greater concentrations of release or a circulating substance
What branch of the autonomic nervous system generally sets the predominant tone for dual innervated organs?
What is miosis? What is the opposite?
Miosis is the parasympathetically stimulated pupillary constriction; Opposed by SNS stimulated mydriasis
What is the response of vasculature to muscarinic stimulation?
What is the effect of stimulating a B2 adrenergic receptor?
What is the effect of stimulating a B1 receptor?
Increased contractile force of the heart and heart rate
What is the effect of stimulating A1 or A2 adrenergic receptors?