Autonomic Pharmacology Flashcards
What are the three divisions of the peripheral nervous system?
sympathetic
Parasympathetic
Enteric
What neuron type innervates muscles?
Alpha motor neurons
Sympathetic preganglionic fibers are
(LONG/SHORT) compared to sympathetic post-ganglionic fibers?
short
Parasympathetic ganglia cells are clustered where?
Within the walls of organs
Which are longer in the parasympathetic system: pre or post-synaptic ganglia?
Presynaptic
What is the one exception to the two neuron organization of the ANS?
adrenal medulla
The response to a stimulus in the somatic nervous system is always (excitatory/inhibitory)?
Excitatory
True or false: responses to a stimulus in the ANS can either be excitatory or inhibitory
True
What are the fibers that comprise the autonomic ganglia?
B fibers
Why is visceral pain usually dull, and poorly localized?
A preganglionic
axon diverges to an average of 8 – 9 post ganglionic neurons
The cell bodies of the preganglionic neurons of the sympathetic pathway are housed where?
In the intermediolateral columns or some ganglia of CNs
The intermediolateral columns run from where to where?
T1-L3,4
There are generally three places that house postganglionic neurons in the sympathetic pathway. What are they?
paravertebral ganglia
Specialized ganglia
Straight to organ
What are the two divisions of the parasympathetic division of the ANS?
Cranio-sacral
Which CNs are a part of the cranial outflow of ANS?
III
VII
IX
X
parasympathetic fibers destined for the pelvic and abdominal viscera emerge from the spinal cord in a bundle of nerves known as what?
the nervi erigentes
What is the ENS division of the ANS?
runs in the layers of the GI tract
What is the myenteric or Auerbach’s plexus?
lies between the external longitudinal and the deeper circular
smooth muscle layer
What does the myenteric/auerbach’s plexus control?
GI motility
The submucosal or Meissner’s plexus lies between what two parts of the GI tract?
between the circular muscularis mucosae
What does submucosal/Meissner’s plexus control?
Ion and fluid movements
What is CN III ganglion?
ciliary
What are CN VII’s two ganglions?
sphenopalatine
Submaxillary
What is CN IX’s ganglion?
otic
True or false: most organs receive both sympathetic and parasympathetic innervation
True
What are the three major organs that do not receive dual innervation from the ANS?
Liver
Kidneys
Adrenal glands
All somatic nerves release what neurotransmitter?
ACh
All preganglionic fibers in the ANS release what neurotransmitter?
ACh
Parasympathetic, postganglionic fibers release what neurotransmitter?
ACh
Sympathetic postganglionic fibers release what neurotransmitter?
Adrenergic
What is the one sympathetic fiber that releases ACh?
Sweat glands
What are cotransmitters?
Neurons release more than one transmitter, each of which interact with specific
receptors and produces effects, often both pre- and post-synaptically.
True or false: hair follicles and thermoregulatory sweat glands only receive sympathetic innervation
True
True or false: ALL preganglionic fibers release ACh
True
What is secreted from the adrenal medulla?
Epi
NE
Muscarinic receptors use what neurotransmitter?
ACh
Renal vasculature uses what neurotransmitter?
Dopaminergic
Nicotinic receptors are found where? What neurotransmitter do they use?
On all postganglionic cell body
ACh
What are homotropic interactions?
Sympathetic neurons neurotransmitter affects itself, to decrease release
What are heterotropic interactions?
One division of the ANS blocks the effects of the other, by synapsing on the bouton
What is the effect of blocking an autoreceptor on a neuron?
Blocks the inhibitory action of the neurotransmitter that is released
Sustained blocking of ganglionic transmission results in what?
Increases sensitivity of organs
Long term blockade of postsynaptic receptors leads to what changes?
INcrease receptors
What are the three mechanisms by which increased ganglionic sensitivity can be effected?
Proliferation of receptors
Loss of removal mechs
Increased post-junctional response
Why is it bad to quickly withdraw beta blockers?
Can lead to hypersensitive BP rebound
What is a neuromodulator?
Substance that affects the secretion of other neurotransmitters
What are the benefits of cotransmission?
Have a longer lasting neurotransmitter to work farther from the site of release
Can change which neurotransmitters release based on stimulation
What is the transporter for choline at presynaptic nerve terminals? What are the drugs that inhibits this transporter?
CHT (choline transporter)
Hemicholiniums
What is the transporter for ACh into vesicles? What is the drug that impedes this?
VAT (vesicle associated transporter)
Vesamicol
What is the toxin that affects the presynaptic bouton for ACh?
Botulinum toxin
What is the MOA of botulinum toxin?
blocks SNARES and SNAPS
What are the drugs that inhibit acetylcholinesterases?
Neostigmine
What is the cation that is needed for neurotransmitter release? What protein does this interact with to cause neurotransmitter release?
Ca
synaptotagmin
What type of proteins are involved in muscarinic receptors?
G-coupled protein receptors
How do nicotinic receptors work?
Allow Na to rush into the cell
What receptor: sphincter muscle of the eye?
M3
What receptor: radial (dilator) muscle of the eye
Alpha 1
What receptor: ciliary muscle of the eye
M3, beta2
What receptor: ciliary body epithelium of the eye?
a2, b1, b2
What are the two second messengers for G-coupled proteins?
Phospholipase C
adenylyl cyclase
Which promotes the active form of G proteins: GDP or GTP?
GTP
Where are M2 receptors found?
In the heart
What are the primary neurotransmitter receptors in the heart?
M2
What is the effect of adenylyl cyclase?
Increases cAMP
What is the effect of phospholipase C?
Increases intracellular Ca via IP3
What part of the eye secretes aqueous humor?
Ciliary body epithelium
What is the part of the eye that drains the aqueous humor?
Canal of schlemm
What happens to the eye and the canal of schlemm when you constrict the ciliary muscle?
Opens the canal
M3 activation contracts the ciliary muscle, to allow for what to happen to vision?
Near vision accomodation
What are the G proteins that are associated with M2 receptors?
Gi
What is the function of gi proteins?
Inhibit adenylate cyclase
What is the effect of M2 stimulation on the SA node?
Decreased heart rate
What is the effect of M2 stimulation on the AV node?
Decreased conduction velocity
What is the effect of M2 stimulation on the atrial muscle?
Decreased atrial contraction
What is the effect of M2 stimulation on the ventricular muscle?
Decreased ventricular contraction
What are the receptors found in the bronchioles?
M3
What are the receptors found in the bronchiolar submucosal glands?
M3
M1 uses which type of G protein?
Gq–PIP
M2 uses which type of G protein?
Gi
M3 uses which type of G protein?
Gq–PIP
What disease should you never use M3 activators for?
Asthma
What is the effect of M3 receptors in the stomach?
Motility/cramps
What is the effect of M1/M3 receptors in glands?
Secretion
What is the effect of M3 receptor activation in the intestines?
Contraction/diarrhea
What is the effect of M3 activation in the stomach?
Increased HCl secretion
Histamine causes what side effect?
Increased acid production in the stomach
What is the effect of stimulating M1 receptors on histamine ECL cells?
Increased histamine, leading to increased HCl secretion
What is the role of M1 in secretion of HCl in the stomach?
Stimulates histamine cells
What is the role of M2 in secretion of HCl in the stomach?
Increases parietal cell HCl secretion
What is the effect of M3 on the detrusor?
Contracts, causing urination
What is the effect of M3 on the trigone/sphincter?
Relaxation, allowing for urination