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9 Cards in this Set
- Front
- Back
What are the factors that affect BP?
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CO = SV x HR
Peripheral resistance (TPR): P / Q Blood volume MAP = CO x TPR |
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What is the long term regulation of BP?
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increase blood volume --> increase BP, increase venous P and VR --> increase EDV and SV --> increase CO --> increase AP --> increase urinary excretion of sodium and water --> lower plasma volume
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What is the regulation of blood volume by ADH?
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decrease in blood volume sensed by atria causes release of vasopressin from posterior pituitary
vasopressin: -potent vasoconstrictor --> increase TPR activating V1 receptors on arterioles -reabsorption of water --> activates V2 receptors stimuli for release: -increase plasma omsolarity detected by central osmoreceptors |
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What is the Renin-AT II-Aldosterone Axis?
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decrease in renal perfusion pressure causes release of renin from juxtaglomerular cells on afferent arteriole
-angiotensinogen --> angiotensin I in plasma by renin -angiotensin I --> angiotensin II by ACE in lung angiotensin II: -stimulates release of aldosterone and causes vasoconstriction of arterioles (increase TPR) -aldosterone increases reabsorption of salt, increase salt and water reabsorption increases BP and MAP |
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What is the regulation of BP by ANP?
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in atria of heart
stimuli: -response to an increase in atrial pressure ANP causes dilation of arterioles to decrease TPR inhibits renin release and causes excretion of water and salt by kidneys |
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What are some circulatory changes during exercise?
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Vascular resistance:
-decrease in blood vessels that supply skeletal muscles but increase in blood vessels that supply GI tract and skin -blood flow in brain stays SAME -increase ejection fraction -increase SV and CO -increase HR |
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What are the different types of circulatory shock?
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circulatory shock - inadequate tissue perfusion and/or inadequate oxygenation of tissues
Hypovolemic: cause: -loss of blood and loss of plasma (burns, severe vomiting, diarrhea) effects: -decrease circulating blood volume, decrease SV, CO, VR, arterial P -cold shock - pale and cold skin, hypotension and tachycardia compensation: -baroreceptor reflex (activation of SNS) -increase plasma and hemodilution (renin, ADH, capillary reabsorption) Cardiogenic: -insufficient CO despite adequate ventricular filling pressure causes: -MI -cardiac tamponade (excessive pericardial fluid) -arrythmia compensation and symtoms: -similar to hypovolemic Septic: -blood poisoning -most often by gram negative infection -LPSs released when cell wall degraded -LPS contains toxic FA with coat -after release of LPS, TNF and IL 1/6 are released -high LPS causes systemic vasodilation, diminished cardiac contractility, and endothelial injury Neurogenic: causes: -anasthesia -brain damage -fainting (syncope) due to cerebral ischemia types: organic: -pathological functional (vaso-vagal syncope): -psychogenic mechanisms: -fainting --> decrease SNS -vaso-vagal syncope ---> excitation of PSNS --> decrease HR --> decrease cerebral blood flow Anaphylactic: -Ag-AB mediated (histamine, serotonin) -lowers BP -increase capillary permeability |
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What happens in Hypertension?
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systolic > 140; diastolic > 90
-90-95 % = primary or essential hypertension: -idiopathic -increase NaCl uptake, increase ECF volume and CO, increase in peripheral resistance 5-10 % = secondary hypertension: -obstruction of renal blood flow -hypersecretion of aldosterone and Adr and NAdr |
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What is Essentail Hypertension and damaging effects?
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increase TPR always
most of the time - increase CO and HR chronic stress (SNS) and high Na+ intake act synergistically in development of hypertenson adaptive response is thickening of arterial wall --> atherosclerosis kidney not able to properly excrete Na+ and H2O Damaging effects: Heart Failure Kidney Disease Stroke Blood vessel damage (thickening of tunica media and acceleration of atherosclerosis and CAD) silent killer |