ANS Con't - Sympathetic (Adrenergic) Flashcards
Constrict pupils =
M3
(PNS)
Stimulate salivation =
M3
(PNS)
Slow HR =
M2
(PNS)
Constrict airways =
M3
(PNS)
Stimulate activity of stomach =
M3
(PNS)
Stimulate activity of intestine =
M3
(PNS)
Contract bladder =
M3
(PNS)
Dilate pupils =
a1
(SNS)
Inhibit salivation =
B
(SNS)
Increase HR =
B1
(SNS)
Relax airways =
B2
(SNS)
Inhibit activity of stomach =
B2
(SNS)
Stimulate release of glucose
Inhibit gallbladder =
B2
(SNS)
Inhibit activity of intestine =
B2
(SNS)
Secrete EPI & NE =
nicotinic
Relax bladder =
B2
(SNS)
Promote ejaculation & vaginal contraction =
a1
(SNS)
Effect of symp & parasymp on eyes:
- Pupillary opening
- Pupillary opening
- symp. - radial muscle of iris; contraction (a1), midriasis
- para - circular muscle of iris; contraction (M3), miosis
Effect of symp & parasymp on eyes:
- Lens focusing
parasymp - ciliary muscle; contraction (M3), near vision
Effect of parasym on:
Gastrointestinal glands, salivary glands, lacrimal glands, nasal glands (GLANDS)
• Effect from M3 muscarinic stimulation
– Watery secretory product
(increase water secretions)
Effect of sym on:
Gastrointestinal glands, salivary glands, lacrimal glands, nasal glands (GLANDS)
• Effect from B adrenergic stimulation – Secretion of protein: enzyme and mucus
• Effect from a adrenergic stimulation – Vasoconstriction➔decrease water
decrease and concentrate secretion
(decrease water secretions, therefore if wanna control runny nose, you’ll activate SNS to dry nose)
(cause a thicker secretion)
Effect of sym on:
Systemic blood vessels (Vasular smooth muscle)
- Skin, splanchnic vessels –> contraction (a1)
- vessels in skeletal muscle –> relaxation (muscarinic)
Effect of parasym on:
Systemic blood vessels (Vasular smooth muscle)
- Endothelial cells - release EDRF (M3)
NE mainly stimulate…
a1 receptors (in vessels)
- increase BP markedly
E has higher affinity for…
B receptor (in cardiac muscle)
- increase HR & contractility
- less effect on mean arterial pressure
Effect of sym on:
GI smooth muscle
- GI smooth muscle –> relaxation (B2)
- GI sphincter –> contraction (a1) (used for drugs that’ll cause nasal drip inhibition & decrease BP)
Effect of parasym on:
GI smooth muscle
- GI smooth muscle –> contraction (M3)
- GI sphinter –> relaxation
How does the baroreceptor reflex work?
(When: heart failure, hypovolemia, hemorrhage, postural changes)
- decrease BP
- carotid sinus/aortic arch decrease firing rate of afferents
- cardiovascular centre
- increase symp. nerve activity & decrease parasymp nerve activity
- increase HR, increase SV, arteriolar constriction
- return BP back towards normal
What is the result of the heart & arteriole (BP or arteriole constriction) systems always working in conjugation?
if give a drug that decrease BP, it’ll cause rxn of heart to increase HR to try to return to normal of if you give a drug that decrease HR SV, you’ll cause arteriole constriction b/c its trying to return BP back & therefore give lower amounts & then ramp it up b/c have to consider rxn of other system
What is Denervation supersensitivity?
Destruction of sympathetic or parasympathetic nerves
– Decrease function
– Chemical adaptation of organ, hence, increase intrinsic tone
Increase response to external neurotransmitter of organs denervated
– Up regulation of cholinergic and adrenergic receptors in end organs
Adrenergic receptors
There are at least 4 types: a1, a2, b1 & b2
– Effector organs: cardiac muscle, smooth muscle and glands
– All respond to both Norepinephrine (NE) and Epinephrine (E)
•NE: a>b
•E: b>a
Functions of Adrenergic Receptor Subtypes
Alpha1
– Vasoconstriction (medical: nasal
decongestant, increase BP (trauma, shock),
– Pupil dilation (Medical: eye exams)
– Inhibits uterine contraction in pregnancy (Medical: Delay birth, side effect)
– Ejaculation (Medical: None yet- drugs in development)
– Contraction of bladder neck and prostate (Medical: Negative side effect)
Functions of Adrenergic Receptor Subtypes
Alpha2
– Located in presynaptic junction
– Inhibits NT release, thus inhibiting sympathetic (adrenergic) activation
(inhibits its own system/NT release; only on certain system (so won’t act. everywhere)
- used for changes in BP, & changes in bladder & prostate activity
- act. of a2 will inhibit
Alpha2 responses
Though it inhibits adrenergic activation, its
not complete nor perfectly opposite of 1
Functions of Adrenergic Receptor Subtypes
Beta1
– Kidney
• Renin release
causes vasoconstriction
– Heart:
• Increases
– Heart rate (tachycardia)
– Force of contraction (increase workload of heart to increase BF)
– Velocity of conduction in AV node (ability of heart to beat faster)
Functions of Adrenergic Receptor Subtypes:
Beta2 & Dopamine
Beta2 (lungs, metabolism & uterinary contraction)
– Bronchial dilation
– Relaxation of uterine muscle
– Vasodilation
– Glycogenolysis
– Glucagon release
(increase glucose into blood)
• Dopamine
– Dilates renal blood vessels *
If you activate ___, you’re helping the lungs to breath. How?
B2
- but if you’re given a drug that activates B2, it’s gonna activate B1 & a1, so you’ll get increase BP, increase HR (therefore not specific but we can use an inhaler)
a1-
Increases vasoconstriction, pupil dilation, relaxes uterine contraction, contraction of bladder and prostate neck, ejaculation (increase BP)
a2-
Cardiac vasoconstriction, Inhibits NE brain release, Inhibits insulin release
B1 -
Increases HR and contraction, Renin release
B2 -
Lung bronchi dilation, relax uterus, vasodilation, Glucose release
a1
2nd messengers, distribution, agonist & antagonist
IP3, DAG
blood vessels, GI sphincter
agonist: pseudophedrine (taken to dry your nose)
antagonist: prazosin (inhibits a1 (good to decrease BP or contraction of bladder neck)
a2
2nd messengers, distribution, agonist & antagonist
decrease cAMP
presynaptic terminal
agonist: clonidine (act. a2 which inhib a1, which lower BP)
b1
2nd messengers, distribution, agonist & antagonist
increase cAMP
heart (to make it beat harder)
agonist: isoproterenol, dobutamine
- act B1, which increase HR & SV (caffeine, nic, etc. any stimulates do this as well)
antagonist: propanolol
- decrease heart activity
B2
2nd messengers, distribution, agonist & antagonist
increase cAMP
airway, GI urogenital
agonist: isoproterenol, terbutaline
- act. B2, help lungs, increase cAMP
antagonist: propanolol
- inibit B2
