CPR Autonomics Flashcards
What is the pathway for Sympathetic stimulation (generally)?
Pre —> ACh —> Nic. Chol. R. On post ganglionic —> NE —> Alpha/beta Adrenergic Rs. On organs
(Pre - short, post - long)
What is the pathway for Parasympathetic stimulation (generally)?
Pre —> ach —> Nic. Chol. Rs. On post ganglionic —> ACh —> Musc. Chol. Rs. On organs
(Pre - long, post - short)
How are pre-ganglionic neurons of the Sympathetic NS activated?
Via hypothalamic nuclei receiving input from brainstem regulatory regions
How do pre=ganglionic fibers of the Sympathetic system leave the CNS?
From thoracic and lumbar regions of SC
Where do we find the synapse b/w most preganglionic axons and Postganglionic cells of the sympathetic system?
In sympathetic chain ganglia relaeasing ACh
Are all alpha and beta adrenergic receptors metabotropic?
Yes
What is the activation of ALpha 1 receptors assoc. w/?
Action on SM is almost always assoc. w/
Contraction of SM
What is the activation of alpha 2 rs. On vascular Sm assoc. w/?
Relaxation/dilation
Where are beta 1 receptors found?
On cardiac myocytes
Where are beta 2 receptors found?
What will they cause?
On smooth muscle
Cause relaxation
Where do pre-ganglionic axons that did not synapse in symapthetic chain go to?
To adrenal medulla to synapse on chromaffin cells of adrenal medulla
-ach —> Nic. CHol. Rs. —> release of epi
Where do preganglionic fibers of the Parasympathetic NS leave the CNS at ?
At cranial and sacral levels
Where is parasympathetic ganglia located?
On or Near target organs
What is M1, 3, and 5 receptors associated w/?
W/ IP3/DAG production and release of intracellular calcium stores
What is M2 and M4 associated w/?
Assoc. w/ Gi proteins and lead to
REDUCTION in cAMP
What is the PNS innervation of the
SA node?
Action and effect?
Cn 10 —> Musc. Rs. On SA
Decreases rate of depolarization
—> slows HR
What is the SNS innervation of the
SA node?
Action and effect?
From T1-T5 —> Beta 1 adrenergic
Increases rate of depolarization
—> increases HR
What is the PNS innervation to
AV node & ventricular conducting pathways (bundle of his, purkinje fibers)?
CN 10 —> Musc. Chol. Rs.
-decreases depolarization rate during phase 0 of slow AP
—> decreases conduction velocity thru AV node and ventricles
(could decrease ventricular rate if AV node is acting as heart pacemaker)
What is the SNS innervation to
AV node & ventricular conducting pathways (bundle of his, purkinje fibers)?
From T1-T5 —> Beta-1 Rs.
-increases rate of depolarization during phase 0
—> increases conduction velocity thru AV node
What is the PNS innervation of the Atrial and Ventricular myocytes?
Atrial myocytes: CN 10 —> Musc. Rs.
(Ventriuclar myocytes- debated)
-decreases Ca entry into myocyte
—> Decreases atrial contractility
(Could decrease ventricular contractility)
What is the SNS innervation of the Atrial and Ventricular myocytes?
From T1-T5 —> Beta 1 (beta-2 maybe)
Increases Ca conductance
—> increases myocyte contractility
Cardiac muscle pumps stronger
what is the major control over innervation of cerebral vasculature?
What ANS innervation will it have
Major control = local
-nueonral activity produces metabolites that vasodilates local blood vessels in proportion to metabolic need
ONLY HAS SNS !!!
What is the SNS innervation of the Cerebral Vasculature ?
Action and effect?
R.: alpha 1 rs
Contracts vascular smooth muscle
—> vasoconstriction of cerebral vasculature
When will SNS innervation to Cerebral Vasculature occur?
Does not occur under normal circumstances
- will only happen when SYSTEMIC BP BECOMES TOO HIGH and might damage the cerebral capillaries
- constructs small starters to decrease blood flow thru caps and protect them
What is the major control of blood flow to heart thru Coronary As.?
Based on local factors associated w/ metabolic need, rather than ANS
What is the PNS innervation of Coronary Blood vessels?
Action and effects?
CN 10 —> Musc. Chol. R.s
SM relaxation —> vasodilates and increases coronary blood flow
What is the overal effect of Vagal stimulation on the heart?
Decrease in metabolic activity
-thus, an increase in coronary blood flow may be overridden by decreased production of metabolites and constriction (local control factors)
What is the SNS innervation of the Coronary As.?
Action and effect?
T1-T5 —> alpha 1
SM contraction —> vasoconstriction and decrease in coronary blood flow
(Short lived though bc this will increase metabolic need and local factors will lead to a vasodilation that overcomes the sympathetic effect)
What is the SNS innervation of cutaneous vasculature?
Action and effect?
From multiple sources —> alpha-1
Contraction of vascular SM —> Vasoconstriction
How are sweat glands innervated by sympathetics?
Action and effect?
Sympathetic Muscarinic
relaxation of vascular SM
—> vasodilation and increase in primary sweat production
What is the SNS innervation of the Vasculature supplying S.M.?
Actions and effects?
Sympathetic - major influence
mult. Sources—> alpha & beta 2
Alpha1 = contracts vasc. Sm —> vasoconstriction of arteries supplying a m.
Beta 2 = relaxes vasc. Sm —> vasodilation of blood supply to a M.
What is the PNS innervation of Vasculature supplying Skel. M.?
—> Musc. Chol. Rs.
Relaxes vasc. Sm —> vasodilates vasc. Supplying Sk.M.
How does PNS innervation affect NO?
May increase nitric oxide release from vascular endothelium
—> produces vasodilation
What is the ANS innervation to Splanchnic vessels?
Sympathetic only
What is the SNS innervation of Splanchnic vessels?
Action and effect?
T5-L2 —> celiac/superior Mesenteric/inferior Mesenteric ganglion —> alpha-1
Contracts Vasc. SM —> Vasoconstriciton of splanchnic blood cells
How do you achieve vasodilation of splanchnic blood cells?
Occurs when sympathetic activity is decreased
And local controls are allowed to exert their influence
(I.e. presence of food in GI —> activates intrinsic nerve plexus of the intestine)
What is the SNS of veins?
Action and effect?
Symp = primary source
—> ALpha 1, alpha 2 and beta 2
Alpha 1: contracts venous SM —> increases return of blood to heart
Alpha 2 and Beta 2: relaxes venous SM —> dilation of veins, slows return of blood to heart
What will the ANS innervate re: lungs?
Innervates SM and mucus glands of the airways
How is blood flow tot he lungs divided?
Into 2 parts
- Bronchial circulation
- Alveolar (pulmonary) circulation
What is bronchial circulation?
Provides o2, removes metabolites to airways that are too thick to get oxygen from air in lungs
Arteries = high oxygen, low CO2
What is Alveolar Circulation?
Blood is being sent to lungs for gas exchange
What controls blood flow to alveoli?
Dictated primarily by local conditions in the alveoli, specifically CO2 and O2 levels
What is the PNS innervation of Pulmonary Vasculature?
Action and effect?
Nucleus ambiguus —> CN 10 —> Muscarinic chol.
(W/ highest amt. of innervation at extra-pulmonary as. And lowest closest to alveoli)
Directly: produces No and releases it from endothelial cells
Indirectly: via No, relaxes vasc. SM
—> vasodilation
What is the caveat for vasodilation pulmonary vasculature?
SM must already be contracted
Implies that this is not necessarily important under normal resting conditions
What is the SNS innervation to the Pulmonary vasculature?
First 5 thoracic ganglia —> alpha 1 and beta 1 and 2
(Will not innervate acinar vessels)
Alpha 1: contracts vasc. SM —> vasoconstriction large pulmonary vessels
Beta 1 and 2 —> vasodilation of large pulm. Vessels
Why is SNS innervation of Pulmonary vasculature important?
Helps maintain Basal Tone in PUlm. A.
Will be activated by mechanoreceptors that detect distension of pulmonary a. Or large airways (or by exposure to cold air or hypoxia-high altitude)
What is the PNS innervation of Upper airways (nasal mucosa) ?
Action and effect?
Trigeminal N. —> sphenopalatine ganglion —> Musc. Chol.
Vasodilation and increased secretion —> Increased mucus secretion
What is the SNS innervation for Upper Airways(nasal mucosa)?
Superior cervical ganglia via CN 7 —> Alpha-1
Has no direct influence on glands
Contracts SM —> vasoconstricts and reduces mucus secretion
What is the PNS innervatio of the Lower airways (trachea and large airways) ?
Action and effect?
Cn 10 —> Musc. Chol.
Contracts bronchial SM and increases synthesis of mucus
—> bronchoconstriction and increased mucus secretion
What is the SNS innervation of Lower Airways (trachea and large airways)?
T1-T5 —> Beta 2
Relaxes bronchial SM
—> Bronchodilator
What is kidney vasculature primarily dictated by?
By ANS
What is the major function of the kidney?
Remove metabolic waste products from the blood
How much blood does the kidney receive per minute?
~2% of blodo pumped by heart / min.
What is the nephron?
Function unit of kidney
What are the parts of a Nephron?
- Bowman’s capsule/space
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule and collecting duct
What is the purpose of Bowman’s capsule/space?
Initial filtration to provide raw material to make urine out of
What is the role of the Proximal convoluted tubule?
Move everything that was filtered into Bowman’s space back to blood via process of reabsorption
&
Move things that need to go into urine via process of secretion
What is the purpose of the Loop of Henle?
Prepares to concentrate urine
Concentrates interstitium and creates gradient that can be used to reabsorb water
What is the role of the Distal convoluted tubule and collecting duct?
Uses hormones to control water and sodium
Fine tunes concentrate
What is the role of the Renal artery?
Supplies blood to the kidney
What vascular components of the kidney are heavily innervated by the SNS?
Afferent and efferent artierole
What is the role of the afferent arteriole?
Controls blood flow INTO the glomerular capillaries
What is the role of the Efferent arterioles?
Controls blood flow OUT of glomerular capillaries
What else does the SNS innervate in the Kidneys? Why?
Will innervate the Juxtaglomerular apparatus to secrete renin
-when BV/BP decreases
What is the SNS innervation on REnal vasculature?
Via alpha-adrenergic fibers
Contracts Vasc. SM —> vasoconstricts Renal A. , afferent arteirole, and efferent arteriole
Results in decreased blood flow to kidney, decreased urine production, and preserved BP to rest of the body
What is the SNS innervation of the Juxtaglomerular Apparatus?
—> granule cells of afferent arterioles —> beta -1 Rs.
-increases release of Renin
What will increased release of Renin lead to?
Leads to
-increased production of angiotensin
—> increases release of aldosterone
—> increased reabsorption of Na and release of ADH
—> ADH will reabsorb water
—> increased production of angiotensin II
==increased blood volume
