6-autonomic Flashcards
what are some autacoids
histamine, serotonin, adenosine, vasoactive peptides, lipid-derived mediators (leukotrienes & prostaglandins), cytokines
what are vasoactive peptides
involved in neuronal and vascular signalling
what are some physiological roles of histamine
immediate allergy and inflammation,
gastric secretion,
neurotransmitter
what are mast cells
mediators of inflammation with contact of antigen
where in the stomach are enterochromaffin like cells
fundus
how is stomach acid released
histamine released onto parietal cells
what cells in the stomach release histamine
enterochromaffin-like cells
what are some white blood cells that release histamine
basophil granules
what happens to mast cell when exposed to the appropriate antigen
degranulate (release granular contents, mostly histamine)
what does insect venom release
histaamine
what is the triple response of lewis
initial localized red spot, then bright red flare, then wheal
what causes the triple response of lewis
local vasodilation, axon reflexes (indirect vasodilation, causes spread), edema
what is neurogeneic inflammation / axon reflex
inflammation that requires the presence of nerve fibres
-nerve impulse double backs and sends signal out to periphery
what is released in the axon reflex
histamine, substance P, CGRP
what does CGRP and substance P stimulate
mast cells, so more histamine is released - positive feedback
what kind of G receptors for H1
Gq
what kind of G receptors for H2
Gs
what does H1 activation on endothelial cells do
NO release to cause vasodilation (similar to M3)
what are the effects of histamine on nerve endings
powerful stimulant - pain, itch, axon reflex, neurogenic inflammation
where is histamine a neurotransmitter
in tubermammillary nucleus of hypothalamus
what does histamine do to arousal
increase
what kind of interactions does histamine make
with glial cells
what does histamine do to blood flow
regulate cerebral and peripheral flow
what do antihistamines do to sleepiness
make you drowzy
what do histamines do to cardiovascular system
vasodilate! redness, warmth, headache
edema
tachycardia
what causes the vasodilation in the cardiovascular system
H1 nitric oxide mediated effects
what does histamine do to HR
reflex tachycardia
what is edema
seperation of endothelial cells, plasma proteins leak out and fluid follows
what does histamine do to respiratory system
bronchiolar constrictor
which H receptor causes bronchiolar constriction
H1
what does histamine do to gastric acid release
increase
which H receptor causes gastric acid release and where are they
H2 receptor on parietal cells
what do parietal cells do
release stomach acid
how does histamine compare to adrenaline
many of the effects are opposite
what is anaphylaxis
MASSIVE allergic response
what causes anaphylaxis (compounds)
histamine, but lots of other things - inflammatory soup (bradykinin, substance P, serotonin, prostaglandins, cytokines)
what are symptoms of anaphylaxis
hypotension, respiratory difficulty, hives, odema
why are antihistamines not super helpful with anaphylaxis
because there are many more mediators other than histamine
what is the best physiological antagonist to histamine
adrenaline
what kind of agonist or antagonist can impair mast cell degranulation
beta 2 agonists
what does cromolyn do
prevents mast cell degranulation and release of inflammatory mediators and histamine
-for asthma
what does nedocromil do
prevents mast cell degranulation and release of inflammatory mediators and histamine
-for asthma
what do older H1 antagonists do
produce sedation, some cause local anesthesia (block Na channel)
what do some older H1 antagonists have as off target effects
anticholinergic, alpha1 and serotonin receptor blocking effects (promiscous)
are H1 antagonists good for asthma or anaphylaxis
noooo
because it is an alpha1 blocker (i think thats why idk)
what are good clinical uses for H1 antagonists
hay fever (allergic rhinitis)
sleeping pills
motion sickness
why are some H1 antagonists drowzy and others arent
some can and cant get through the BBB
what is diphenhydramine
H1 antagonist,
benadryl, classic antihistamine sedative
what is dimenhydrinate
H1 antagonist,
gravol
anti-motionsicknes, sedative
what is loratidine
H1 antagonist,
claritin, non sedative antihistamine, seasonal rhinitis
what is the use for H2 antagonists
reduce acid secretion in stomach
what is ranitidine
H2 antagonist, reduce acid in stomach
what is adenosine
cardiac autacoid and neurotransmitter
what does adenosine do to lungs
bronchospasm!!!
what g protein receptor is A1
Gi
what g protein receptor is A2
Gs
what g protein receptor is A3
Gi
what does it mean when i say adenosine is a cardiac autacoid
released locally in heart
what does adenosine do to heart
slows heart rate and vasodilate
what is theophylline
(adenosine antagonist)
antagonizes bronchoconstrictor effect of adenosine
-used sometimes for asthma
what does caffeine do
antagonist to adenosine, CNS stimulant
what receptors do adenosine antagonists work at
A1, A2, A3
what do adenosine antagonists do to cAMP levels and how
increases it because it inhibits cyclic AMP phosphodiesterase
what happens when you combine beta agonists and adenosine antagonists (cAMP)
increase cAMP levels because beta agonists are Gs and adenosine antagonists inhibit cyclic AMP phosphodiesterase
what does salbutamol do and which receptors
b2 agonist, rescue inhaler (for asthma attacks)
what happens with repeated administration of salbutamol
b2 downregulation
what does ipratropium do and what kind of drug is it
muscarinic antagonist for COPD
how does ipratropium work
helps remove parasympathetic tone so that the lungs can dilate
what does montelukast do
antagonizes leukotriene B4 (prophylactic for asthma)
what do corticosteroids do
anti-inflammatory, for asthma
what does cromolyn do
prevents mast cell degranulation, for asthma
what are biologics and when are they used
interleukin 5 antibodies (to stop it from interacting with its receptor)
good for severe asthma
how are biologics given
subcutaneous injection WAHHH
