Term
| parasympathetic branch innervates: |
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Definition
cardiac and smooth muscle
gland cells
nerve terminals |
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Term
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Definition
sweat glands
cardiac and smooth muscle
gland cells
nerve terminals
renal vascular smooth muscle |
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Term
| somatic nerves innervate: |
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Definition
skeletal muscle
(nicotinic receptor --> ACh released) |
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Term
| _______ nerves carry impulses away from the CNS to the target organs |
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Definition
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Term
| _______ nerves have LONG preganglionic fibers |
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Definition
Parasympathetic!
leaves cranial & sacral areas of the spinal cord |
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Term
| ______ is released in postganglionic neurons of the SYMPATHETIC nervous system. |
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Definition
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Term
| ________ have SHORT preganglionic fibers |
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Definition
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Term
| Parasympathetic receptors: postsynaptic? effector? |
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Definition
postsynaptic: Nicotinic receptor
effector: muscarinic |
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Term
| ααααsympathetic receptors: postsynaptic? effector? |
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Definition
postsynaptic: nicotinic receptor
effector: (NE) α, β |
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Term
| ______ neurons exit the CNS from thoracolumbar region of the spinal cord |
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Definition
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Term
| _______ neurons exit the CNS from the craniosacral region |
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Definition
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Term
| Preganglionic nerves of both branches of the ANS release ______. |
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Definition
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Term
| Al neurons that release ACh are called ____. |
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Definition
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Term
| Neurons that release NE are called ___. |
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Definition
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Term
| How are sweat glands an exception to the neurotransmitter rule? |
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Definition
| They are sympathetically innervated; however, their postganglionic nerves are CHOLINERGIC (release ACh instead of NE) even though they are anatomically sympathetic (come out of the middle of the spinal cord) |
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Term
| Certain blood vessels in the kidney are innervated by ___1___ nerves that release __2__ instead of NE. |
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Definition
1) sympathetic
2) dopamine!
** Dopamine is a weak agonist on alpha and beta receptors, but also activates its own dopamine receptors in a more potent manner. ** |
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Term
| Example of autonomic nerves that are nonadrenergic and noncholinergic (NANC) |
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Definition
1) Coprus cavernosum of the penis is innervated by nerves that release NO. Release of NO acts on smooth muscle of the cavernosum, producing relaxation and engorgement with blood to produce an erection.
2) Other NANC neurons release a variety of peptide and non-peptide transmitters (not just NO). Found in: GI tract, lungs, urinary tract, and CNS |
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Term
| How is the adrenal gland an exception to the dual innervation rule? |
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Definition
Innervated exclusively by a preganglionic nerve but not a postganglionic nerve of the SYMPATHETIC nervous system.
Transmitter released: ACh
Enhanced release of ACh at adrenal medulla activates NICOTINIC receptors to increase secretion of EPI (adrenaline) by cromaffin cells into the bloodstream. |
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Term
| The vast majority ofsmall arteries and arterioles are innervated only by the ____ branch of the ANS. |
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Definition
SYMPATHETIC!
arterioles = ALPHA receptors!!!
Blood flow and BP are controlled by the sympathetic nervous system.
Parasypathetic may influence flow in certain vascular beds, such as corpus cavernosum, but otherwise has little to no effect on blood flow or BP. |
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Term
| Lungs (bronchi and bronchioles) are strongly innervated by the __1___ nervous system, but only weakly innervated by the ___2__ branch. |
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Definition
1) parasympathetic (ACh)
2) sympathetic
** SMC contraction cellular signal = Ca2+ moved inside by DAG, IP3** |
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Term
| How do the few blood vessels innervated by the parasympathetic n.s. respond to neurally-relased ACh? |
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Definition
Skeletal muscle, coronary arteries, corpus cavernosum...all respond LOCALLY by dilating due to release of NO from vascular endothelial cells.
But... injections of ACh and similar drugs cause systemic vasodilation because ALL endothelial cells have muscarinic receptors that are coupled to NO release.
However...if endothelium is removed from blood vessels, they will CONSTRICT (contract) in response to ACh bc of the action of ACh to stimulate M-1 receptors on the exposed smooth muscle |
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Term
| Skeletal muscles are innervate by __1__ nerves which release __2__ and activate __3__ receptors. |
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Definition
1) somatomotor nerves
2) ACh
3) nicotinic
**Nm = nicotinic receptors of the somatomotor nervous system found on skeletal muscle.** |
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Term
| A cholinergic junction illustrates: |
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Definition
1) synapses in all autonomic ganglia (sym & parasym)
2) the "synapse" btwn sym. preganglionic neurons & adrenomedullary cromaffin cells
3) parasym. neuroeffector junction
**↑ action potential frequency
↑ Ca2
↑ACh
Acetyl cholinesterase inhibitor = nerve gas |
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Term
| What is the noradrenergic neuroeffector junction? |
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Definition
junction between sympathetic postganglionic neuron and an effetor cell
Tyrosine -> L-Dopa -> Dopamine
DβH converts Dopamine to NE
(pg. 16) |
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Term
| Epinephrine can do two things: |
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Definition
1) stimulate alpha-1 to produce constriction (i.e. arterioles)
2) stimulate beta-2 to produce dilation
**Think of fight or flight response: You want to ↑ blood flow in the limbs but shunt blood flow in middle body (gut and gland) |
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Term
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Definition
agonist drug that imitates effects of the sym. nervous system and thus acts like either NE or EPI
includes alpha and beta adrenoceptor agonists |
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Term
|
Definition
breakdown of glycogen to glucose
mainly in liver and skeletal muscle |
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Term
|
Definition
| specialized cells near the glomeruli in the kidney that secrete the enzyme renin into the bloodstream in response to neural and other influences |
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Term
| relative potencies of NE (from postgang. neurons) and EPI (in blood from adr. medullary cromaffin cells) on different receptor subtypes |
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Definition
alpha-1: NE>EPI
alpha-2: NE>>>>>EPI
beta-1: NE<EPI
beta-2: NE<<<<<EPI |
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Term
List the primary alpha-1 receptor mediated effects
(NE, EPI, and alpha agonist drugs) |
|
Definition
CONSTRICTION OF:
arteriolar smooth mucle
genitourinary smooth muscle
radial muscle of eye
RELAXATION OF: intestinal smooth muscle
INCREASED GLYCOGENOLYSIS in liver |
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|
Term
|
Definition
Alpha-1 SELECTIVE:
phenylephrine, methoxamine, mephentermine, metaraminol, tetrahydrozoline, naphazoline, mitodrine
NONSELECTIVE (w. some Beta activity):
dobutamine, ephedrine, pseudoephedrine, phenylpropanolamine
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Term
| Therapeutic uses of alpha agonist drugs: |
|
Definition
- nasal decongestion (orally & topical in nasal sprays)
- local anesthetic preparations
- ocular anti-redness preparations
- hypersensitivity & anaphylaxis: (epinephrine = DOC) |
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Term
| adverse effects of alpha agonist drugs |
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Definition
exteme elevation in BP
cerebrovascular accident
myocardial necrosis & infarction |
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Term
Predominantly BETA-2 mediated effects
(EPI or β agonist drugs) |
|
Definition
RELAXATION OF:
arteriolar smooth muscle
bronchiolar smooth muscle
intestinal smooth muscle
uterine smooth muscle
ciliary muscle of eye
spleen capsule
INCREASED K+ UPTAKE in skeletal muscle
INCREASED INSULIN SECRETION in pancreatic islet beta cells |
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Term
Predominantly BETA-1 mediated effects
(EPI, NE, or β agonist drugs) |
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Definition
HEART SA Node: ↑HR (positive chronotropic effect)
HEART AV Node: ↑conduction velocity (pos. dromotropic effect)
HEART His-Purkinje cells: ↑conduction velocity & automaticity
HEART Atrial Muscle: ↑contractile force (pos. inotropic effect)
HEART Ventrical muscle: ↑contractile force
KIDNEY juxtaglomerular cells: ↑renin secretion |
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Term
|
Definition
Beta-2 Selective:
tertbutaline, metaproterenol, albuterol, isoetharine, perbuterol, fenoterol, salmeterol, ritodrine
Nonselective:
isoproterenol (no α activity), dobutamine, ephedrine, pseudophedrine, phenylpropanolamine (some α activity) |
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Term
| therapeutic uses of beta agonist drugs |
|
Definition
- anaphylactic shock (EPI = DOC)
- cardiogenic shock (low cardiac output, BP, or both); β agonists or fenoldopam
- Bronchospasm
- Cardiac Arrest (with alpha agonists)
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|
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Term
| Adverse effects of beta agonist drugs |
|
Definition
severe tachycardia & cardiac arrhythmias, angina pectoris, cardiac, necrosis and damage
skeletal muscle tremors |
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Term
|
Definition
- neurotransmitter in brain and in autonomic neurons going to kidney
- activates its own receptors (D-1 and D-2) as well as alpha and beta adrenoceptors
- used to improve renal blood flow in conditions of shock (very low BP)
- Fenoldopam: Seceltive D-1 receptor agonist, also used in treating shock. |
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Term
| Prazosin vs. Phentolamine |
|
Definition
Prazosin:
- newer. Selective alpha-1 blocker.
- Causes vasodilation; bronchodilation for anaphylaxis
Phentolamine:
- older drug; nonselective a-1 and a-2 blocker.
- Inhibits NE to inhibit its own release, resulting in STIMULATION = more NE!
- more severe effects than prazosin |
|
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Term
| common adverses effects of alpha blockers |
|
Definition
fluid retention
tachycardia (BP↓, HR↑) |
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Term
| Phenylephrine is a(n) ____ drug that causes ____. |
|
Definition
Alpha agonist
vasoconstriction of arteriolar smooth muscle
decreased blood flow |
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Term
| EPI stimulates ___ receptors and produces ____. |
|
Definition
Alpha-1, beta-1, beta-2
vasoconstriction, decr. blood flow (a1)
positive inotropy (ventric. cardiomyocyte), ↑CO (B1)
bronchodilation (bron. sm. muscle), ↑air flow (B2) |
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Term
| NE stimulates ____ receptors and causes ____. |
|
Definition
alpha-1, alpha-2, beta-1
vasoconstriction, decr. blood flow (a1)
inhibits NE to inhibit own release (a2)
bronchodilation, ↑air flow (b2) |
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Term
|
Definition
B-1 agonist
causes positive inotropy (ventricular cardiomyocyte)
increased cardiac output |
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|
Term
|
Definition
nonselective beta agonist
positive inotrophy (vent. cardiomyocyte), ↑ CO (B!)
bronchodilation, ↑ air flow (B2) |
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|
Term
|
Definition
B-2 agonist used to treat asthma
effector: bronchiolar smooth muscle
signal: cAMP
causes: relaxation; therefore, opening airways
bronchodialtion, ↑ air flow |
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Term
Fenoldopam is useful for the treatment of ____.
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|
Definition
cardiogenic and hypervolemic shock (severely reduced CO)
dopamine/fenoldopam have ability to selectively dilate renal blood vessels and ↑ renal blood flow
renal vasodilation helps maintain perfusion of kidneys when systemic BP or CO is very low |
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Term
| What is the rationale for the therapeutic effects of alpha agonists on nasal decongestion? |
|
Definition
congestion is caused by dilation of blood vessels, engorging & swelling mucosa of nasal passages
activation of alpha adrenoceptors on vascular s.m. in the vessels of the nasal mucosa causes blood vessels to constrict, counteracting the effect of vasodilation, and opening up nasal passages. |
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Term
| What is the therapeutic effect of alpha agonists used for local anesthetic preparations? |
|
Definition
produce local vasoconstriction and restriction of systemic absorption, which has 2 major effects:
1) ↑duration & magnitude of anesthetic effect
2) decreases systemic toxicity of local anesthetic |
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Term
| What is the rationale for therapeutic effect of alpha agonists used for ocular anti-redness? |
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Definition
| Redness in the whites of the eyes is caused by vasodilation of the surface blood vessels, which is counteracted by vasoconstriction effects of alpha agonists |
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Term
| What is the rationale for therapeutic effects of alpha agonists on anaphylactic shock? |
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Definition
Anaphylaxis is a mix of very low BP and constriction of upper airways produced by antigen-induced release of histamine
EPI counteracts low BP by producing systemic vasoconstriction (a1) and the bronchoconstriction by relaxing s.m. around airways (b2)
EPI also impedes release of histamine from mast cells (Beta effect) |
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|
Term
What are the rationales for adverse
effects of alpha agonists? |
|
Definition
Extreme elevation in BP: usually caused by overdose; extreme effect of vasoconstriction
Cerebrovascular accident: vasoconst. of cerebral blood vessels
myocardial necrosis/infarction: extreme vasoconstr. of coronary microvessels |
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