Neurohumoral Control of CV System Flashcards
Which system outflows from thoracolumbar regions?
Sympathetic
Which system outflows from Craniosacral regions?
Parasympathetic
Whats the normal order of the higher brain centers?
Cerebral cortex–Hypothalamus—Pons—Medulla—Spinal cord
Which has significantly more innervation to blood vessels, sympathetic or parasympathetic?
Sympathetic
Which nerve is parasympathetic innervation to the heart?
CN X=Vagus Nerve
What parts of the heart to the vagus nerve innervate?
Upper portion of heart. SA/AV Node
What parts of the heart to the sympathetic innervations lead to?
Upper and lower portions of the heart. SA, AV, and ventricles of heart.
Describe parasympathetic ganglion from the vagus nerve:
Parasympathetic ganglion is very close to the heart (and also more identifiable).
Cardiac accelerators outflow from where?
T1-T4.
Describe the sympathetic ganglion from the cardiac accelerators:
The ganglion is very far from the heart.
Stem from the cortex that all cardiac accelerators run to.
Nervous system control of peripheral blood flow is mediated mostly by which system?
Sympathetic.
What are the three main components to nervous control of circulation?
Redistributing blood flow.
Increasing pumping activity of the heart.
Providing rapid control of blood pressure.
List the individual fight-or-flight responses:
Increased BP.
Increased blood flow to active muscles
(decreased blood flow to GI Tract and kidneys),
Increased rate of cellular metabolism throughout body,
Increase blood glucose concentration.
Increased glycolysis in liver and in muscle.
Increased muscle strength.
Increased mental activity.
Increased rate of blood coagulation.
What do the adrenal glands secrete?
Epinephrine 80%.
Norepinephrine 20%.
Sympathetic activation of the heart produces what 4 things?
Chronotropy=HR.
Inotropy=contractility.
Dromotropy=conduction velocity.
Lusitropy=relaxation
Beta 1 activation creates what?
Increased chronotropy and increased inotropy.
Alpha 2 activation creates what?
Inhibits transmitter release
Alpha 1 activation creates what?
Vasoconstriction.
Beta 2 activation creates what?
Vasodilation.
Bronchodilation.
Uterine relaxation.
Glycogenolysis.
What two receptors are the primary effect site of NE?
Alpha 1 and Beta 1.
What is an example of an Alpha 2 agonist?
Precedex and clonidine.
What part of the body does NE create vasodilation?
Particularly in muscle.
List the Catecholamine synthesis in order:
Tyrosine» Dopa» Dopamine» Secretory Granules» Norepinephrine» Epinephrine.
Drug affinity for Alpha 2?
Norepi > Epi
Drug affinity for Beta 1?
Epi > Norepi
Drug affinity for Beta 2?
Primarily Epi
Drug affinity for Alpha 1?
Norepi > Epi
How is lusitropy enhanced?
Phosporylation of phospholamban which enhances Ca++ uptake by the sarcoplasmic reticulum.
What two major components of heart function are altered with milrinone?
Lusitropy and contractility.
Beta 1 activation produces what in the heart?
Increase contractility, increased chronotropy, increased dromotropy, and increased lusitropy.
Explain what happens when NE binds to alpha 1 receptor on smooth muscle (vessels).?
NE binds to alpha 1 receptor and causes movement of Ca++ into cells which allows for smooth muscle contraction and vasoconstriction.
What receptor does acetlycholine bind to?
Cholinergic receptor.
What breaks down acetylcholine in the synapse?
Acetlycholinesterase
What two byproducts are left after acetylcholine is broken down by acetylcholinesterase?
Choline and Acetate.
What are the two types of cholinergic receptors?
Muscarinic and Nicotinic.
Muscarinic receptor location:
CNS. Post-ganglionic neurons. Cardiac tissue. Secretory glands. Smooth muscle.
Nicotinic receptor location:
CNS.
Autonomic ganglia.
Adrenal medulla.
Neuromuscular junction.
Why do you give both robinul and neostigmine?
Neostigmine increases acetylcholine (though its target is nicotinic, some of it activates muscarinic). Robinul combats the bad side effects that can be caused from muscarinic involvement (mostly cardiac tissue, but also secretory glands). Robinol blocks the acetylcholine at the muscarinic sites.
What causes the kidney to secrete renin?
Sympathetic stimulation.
Hypotension.
Decreased sodium delivery.
When Renin and Angiotensin act on ACE, and ultimately Angiotensis II, what symptoms will we see?
Cardiac and vascular hypertrophy.
System vasoconstriction.
Thirst.
Adrenal cortex will release aldosterone.
What will adrenal cortex release of aldosterone do?
Renal sodium and fluid retention, which increases blood volume, which increases CO, which increases arterial pressure.
What two drugs can be used to counteract the Renin-Angiotensin-Aldosterone System?
ARBs. (angiotensin receptor blockers) and and ACE inhibitors.
Where is vasopressin released from?
Pituitary gland
What 4 things are caused by vasopressin release?
- Vasoconstriction.
- Renal Fluid Reabsorption.
- Increased blood volume.
- Increased arterial pressure.
What can cause vasopressin release?
Sympathetic stimulation.
Decrease atrial receptor firing.
Angiotensin II.
What causes release of Atrial Natriuretic peptide?
Atrial Distension.
What does release of Atrial Natriuretic peptide cause?
Decreased SVR, CVP, CO, and Arterial BP. Blood volume
What does aldosterone do to blood volume, CO, and arterial BP?
Increase.
Increase.
Increase
What does vasopressin do to blood volume, CO, Arterial BP?
Increase.
Increase.
Increase
What does vagal activity do to blood volume, CO, arterial BP?
no Change.
Decrease.
Decrease.
What does angiotensin II do to blood volume, CO, Arterial BP?
Increase.
Increase.
Increase.
What does Atrial Natriuretic Peptide do to blood volume, CO, Arterial BP?
Decrease.
Decrease.
Decrease.
What direct effects does hypoxia have on the heart?
Decrease in contractility and Decrease in HR.
What indirect effects does hypoxia have?
Sympathetic nervous system activates:
Increase HR, contractility, SVR.
What direct effects does hypercarbia have on the heart?
Decrease Contractility.
What indirect effects does hypercarbia have?
Sympathetic nervous system activates:
Increase HR, contractility, and SVR.
With hypoxia and hypercarbia, the direct effects are (+/-) and indirect effects are (+/-)?
Direct effects are negative.
Indirect effects are positive.