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41 Cards in this Set
- Front
- Back
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What kind of fibers are barroreceptors?
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they are afferent sensory fibers.
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At what blood pressure are the barroreceptors activated?
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They are activated between 80 and 120 mmHg
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Once blood pressure information is received by the barroreceptors where is it than transmitted?
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The information is than sent to the Medullary cardiovascular control center.
-Than parasympathetic and sympathetic neurons are activated in order to oppose the chang in blood pressure and keep MAP constant. |
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What are two mechanisms that are effected by increasing Atrial Pressure?
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-There is a decrease in activity of Renin-Angiotensin-Aldosterone System (RAAS) which increases sodium excretion.
- Also a decrease in Kidney tubular reabsorption of Na+ (pressure natriuresis) |
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What are three mechanisms that are activated due to an increase in blood volume?
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-There is an increase in the activity of low pressure barroreceptors in the heart
-ADH secretion is decreased due to atrial strech -Also secretion of ANP (Atrial Natriuretic Peptide) increases. This is released when the atria expands due to increased plasma volume. |
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Describe the Atrial Natriuretic Peptide Pathway
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-Due to increases plasma volume ANP is secreted.
-Plasma ANP is than increased which will decrease plasma aldosterone. -The increase in plasma ANP and the decrease in plasma aldosterone will decrease Na reabsorption in the kidney tubules and cause afferent dilation; efferent constriction (thus increasing GFR) in the arterioles. -This will than lead to the increase in Na+ excretion and in turn cause Increase H2O excretion. |
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What is Circulatory Shock?
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This is defined as the decrease in MAP.
-Due to a decrease in CO or R. |
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What can be the cause of Hypovolemic Shock?
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Severe hemorrhage, Excessive vomiting, diarrhea, and polyuria
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What can be the cause of cardiogenic shock?
How about Vasogenic shock? |
-A weakened heart
-Septic shock and Anaphylaxis |
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What cells release renin?
What does renin do? |
The Juxtaglomerular cells.
-Renin constricts the afferent renal arterioles in an attempt to preserve blood volume. |
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How does the increase in renal sympathetic nerve activity lead to the increase in blood volume?
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This increase leads to increases in RAAS activity and ADH secretion which decreases the amount of Na+ and water excreted.
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What are some of the effects of the decreased regional blood flow?
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-a decrease in O2 and blood pH which activates peripheral chemoreceptors
-a decrease in pH of brain ECF which will activate central chemoreceptors. *This also has an effect of increasing respiration to increase oxygen. It also has a major vasoconstrictive effect on the renal tubules.* |
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Where is Angiotension Converting Enzyme (ACE) found in very high conc.?
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In lung tissue.
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How does Angiotension 2 affect the Adrenal cortex?
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It stimulates the release of Aldosterone which takes its affects on the renal distal tubules by causing the retention of salt and H2O.
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What are some of the properties of ADH?
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It is a potent vasoconstrictor and it inserts aquaporin channels into the collecting tubule to increase salt and water absorption.
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what is a water diuresis?
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A condition in which you are excreting water while absorbing Na+ ions.
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What are some of the effects of the decreased regional blood flow?
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-a decrease in O2 and blood pH which activates peripheral chemoreceptors
-a decrease in pH of brain ECF which will activate central chemoreceptors. *This also has an effect of increasing respiration to increase oxygen. It also has a major vasoconstrictive effect on the renal tubules.* |
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Where is Angiotension Converting Enzyme (ACE) found in very high conc.?
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In lung tissue.
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How does Angiotension 2 affect the Adrenal cortex?
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It stimulates the release of Aldosterone which takes its affects on the renal distal tubules by causing the retention of salt and H2O.
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What are some of the properties of ADH?
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It is a potent vasoconstrictor and it inserts aquaporin channels into the collecting tubule to increase salt and water absorption.
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what is a water diuresis?
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A condition in which you are excreting water while absorbing Na+ ions.
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What is a slow responce in compensating for blood loss?
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due to the decreased arterial pressure there will also be decreased capillary hydrostatic pressure
-In responce to this there will be fluid absorption from the interstitial compartment which will increase plasma volume. |
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What are the fluid shifts in the body after a Hemorrhage?
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Plasma volume is replaced to more than it was before hemorrhage, total blood volume is a little bit less than it was at start, and red blood cells are not replaced.
-However the replacement of red blood cells (Erythrocytes) requires the release of hormone erythropoietin by the kidneys to stimulate erythropoiesis and/or whole blood transfusions. This process takes days to weeks. |
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What causes diastolic dysfunction?
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This is the consequence of prolonged hypertension (elevated MAP).
*This increases EDV and weakens the heart muscle* |
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What is the importance of the Left anterior descending branch of the heart?
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It is the major pathway for blood supply to the left ventricle.
*So if this is clogged you die* |
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So what is systolic dysfunction a consequence of?
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Is a consequence of damage to cardiac ventricular tissue resulting from decreased coronary blood flow. (i.e., a heart attack)
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What are some problems with the cardiovascular responces due to cardiac failure?
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1. the ventricles become engorged with blood, so much so that SV actually decreases
2. Edema than results from this |
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What is the cause of Edema?
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This is the result of the ventricular pressure being so high that the blood flow backs up due to decreases in SV. This causes the hydrostatic pressure on the venous side of the circulation to increase.
-This means that there is a prolonged period of filtration and what ever the lymphatic vessels cannot absorb stays in the interstitial space, resulting in Edema. |
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What is Pulmonary edema?
Why is this dangerous? |
This is when the left ventricle fails to pump as much blood as the right ventricle. This results in an increase in pulmonary capillary hydrostatic pressure gradient (thus causing an increase in net filtration pressure).
-B/c it increases the diffusion distance for oxygen!! your fucked! |
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In heart failure what is the disadvantage of the regulatory feedback mechanisms over the longterm?
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They are counterproductive and end up making things worse!!!
-ex. the increase in total peripheral resistance which makes a failing heart work harder. |
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The responses of the body to cardiac failure are nearly identical to what other type of physiological response?
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It is almost identical to the physiological responses invoked during hemorrhage, but the responses are sustained for longer periods of time due to sustained hypervolemia
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What is the function of the drug digitalis?
How does it take effect? |
Digitalis is a cardiac glycoside and it helps prevent heart failure by increasing contractility which prevents fluid buildup.
-It does this by poisoning the +Na+-K+ -ATPase pump. this decreases the amount of Na+ leaving the cell which slows down the rate of the Na/Ca exchanger. Thus increasing intracellular levels of Ca2+. |
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What are some treatments for Cardiac Failure?
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-Diuretics
-Cardiac inotropic drugs (ex. digitalis) -Inhibit ADH binding to receptors in kidney and vascular smooth muscle -Inhibit RAAS system (ACE inhibitors block formation of Angiotension 2 and Aldosterone) -Vasodilator drugs: organic nitrates |
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What is Anaphylaxis?
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It is an extreme allergic reaction.
-A type of allergic response classified as immediate hypersensitivity -Mediated predominately by IgE antibodies, mast cells, and basophils -rapid onset (within a few minutes) |
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What cells of the Immune system are primarily involved with the humoral immune responses?
The Cell-mediated immune responses? |
-B cells
-T cells |
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What are antibodies essentially?
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They are just the variable regions of B-cell receptors.
*The constant region just acts as an anchor* |
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What is the only way a T-cell can recognize an antigen?
Where are MHC 1 proteins found? Where are MHC 2 proteins found? |
If can be recognized if the antigen binds to MHC proteins.
-They are found on virtually all cells in the body except for red blood cells. -These are found only on the surface of macrophages, B-cells, and macrophage like dendritic cells. Collectively these are called APC cells (Antigen presenting cells) |
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Describe the interaction of T cells with MHC molecules.
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1. an antigen inside the cell associates with the MHC molecule and is transported to the cell surface.
2. Then the combination of MHC molecule and antigen is recognized by the helper T cell, alerting it to the infection. |
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Describe the T Helper cells Role in Anaphylaxis
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When the T helper cell binds to MHC on the B cell it releases cytokines (IL2) which stimulate the proliferation of plasma B cells and Memory B cells that differentiate into IgE-producing plasma cells.
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What is the problem with IgE receptors being in the cell membranes of mast cells and basophils?
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These cells contain secretory vesicles that release histamines and other inflammatory mediators when the IgE receptors are excited by antigens.
-This causes bronchial smooth muscle contraction (visceral smooth muscle contraction), vascular leakage (swelling), and Hypotension (shock) |
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What is angio-edema?
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This is the swelling of tissues around airways which eventually closes the throat.
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