Term
| Transmural Blood Pressure |
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Definition
Pressire Inside - Pressure Outside
Pi>Po cause vasodilation
Pi<Po cause visoconstriction=The "BP" we measure with a cuff |
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Term
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Definition
P1 - P2
Difference in pressure along the length of a vessel
Responsible for blood flow in vascular system
P1>P2 always in healthy individuals |
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Term
| Mean Arterial Pressure (MAP) |
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Definition
Diastolic pressure - 1/3 x (systolic - diastolic)
Used for P1 when using Aorta of artery with changing pressure |
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Term
| Normal Heart Pressures (mmHg) of RA, RV, LA, LV, Aorta, Pulmonary Artery |
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Definition
| Right Atrium: -4 to 4 Right Ventricle: 25/0 Pulmonary Artery: 25/8 Left Atrium: 7 Left Ventricle: 120/0 Aorta: 120/80 |
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Term
| Systemic and pulmonary system driving pressures |
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Definition
ΔP systemic circulation = Mean Arterial Pressure – Right Atrial Pressure
ΔP pulmonary circulation = Mean Pulmonary Artery Pressure – Left Atrial Pressure |
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Term
| Laminar and Turbulent Flow |
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Definition
Laminar flow- slowest near edges b/c touches wall; fastest in center of lumen
Turbulent flow- needs greater pressure to maintain flow
-Causes sound (cardiac auscultation)
-Can be normal or pathological |
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Term
| Method of indirect measurement of cardiac output (CO) |
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Definition
Echocardiogram
-Measures changes in ventricular dimensions with each heart beat
-Also used to examine heart structures |
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Term
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Definition
| Cardiac Output (CO) = O2 Consumption (VO2) / ([Arterial O2] - [Venous O2]) |
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Term
The following data were collected from a patient. What is the patients cardiac output?
• Oxygen consumption = 250 ml O2/min
• Pulmonary vein oxygen content = 0.20ml O2/ml blood
• Pulmonary artery oxygen content = 0.15ml O2/ml blood |
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Definition
CO = VO2 / (Ca – Cv)
= 250ml O2 per min / (0.20ml O2 / ml blood – 0.15ml O2 / ml blood)
= 250ml O2 per min / 0.05ml O2 per ml blood
= 5000 ml or 5 L |
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Term
| Vascular compliance- arteries and veins |
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Definition
Measures change in volume produced by given change in pressure
-Compliance=vessel's ability to stretch without recoil force
-Tone-stiffness of vascular wall
Arteries- low compliance
Veins- high compliance at low pressure, but low compliance under high pressure
-This is why veins can be used in coronary artery bypass graft |
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Term
| Static and Dynamic Compliance |
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Definition
Static- physical property of a vessel
-Altered by age and disease
Dynamic- change in vascular tone due to smooth muscle contraction due to sympathetic activity
-Tone=stiffness of vascular wall |
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Term
| Changes in compliance can be due to |
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Definition
-Age (static)
-Arterial disease (static)
-Constriction (dynamic- sympathetic a1 receptors) |
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Term
| Vein "reservoir" used to increase cardiac output (CO). (1) Describe the process and (2) when this would happen |
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Definition
-Increase sympathetic activity to smooth muscle cells
-Constrict and increase vascular tone (stiffness)
-Increased tone causes decrease in venous compliance
-Venous blood reservoir displaced toward heart
-Increased venous return and cardiac output
-Due to hemorrhage, dehydration, exercise |
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Term
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Definition
Keeps blood moving during ventricular diastole
-Aorta distended during systole
Recoils during diastole, pushing blood forward through systemic circulatory system |
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Term
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Definition
Measure left heart pressure-->left atrium
-Measure valve pathologies
-Normal= 8-10mmHg |
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Term
| Starling Forces and Transcapillary Fluid Exchange |
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Definition
Net driving pressure = (Pc + πi) - Pi +πc) = forces out - forces in
+ = filtration, more out than in
- = reabsorption, more in than out
Filtration>reabsorption
-Lymphatic system makes up for loss |
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Term
| Edema due to Right heart failure |
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Definition
• Backup of fluid in systemic veins & capillaries
• Increased systemic Pc
• Increased filtration
• Peripheral edema |
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Term
| Edema due to left heart failure |
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Definition
• Backup of fluid in pulmonary veins & capillaries
• Increased pulmonary capillary Pc
• Increased filtration
• Pulmonary edema |
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Term
| Edema due to liver failure or kidney disease |
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Definition
• Reduced plasma protein production
• Decreased πc
• Decreased reabsorption
• Peripheral edema |
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Term
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Definition
• Capillary fluid loss, but no protein loss
• Increased πc (proteins concentrate in plasma)
• Increased reabsorption
• Help to maintain blood pressure |
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Term
| Edema due to lymphatic obstruction (surgery, radiation, etc.) |
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Definition
• Reduced flow from interstitial tissue to lymph system
• Increased Pi (fluid accumulation in interstitium)
• Increased reabsorption, but exceeds capacity of capillaries to reabsorb
• Peripheral edema |
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Term
| Edema due to inflammation |
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Definition
• Increased vessel permeability to proteins
• Increased πi (proteins in interstitium)
• Increased filtration
• Peripheral edema (usually localized) |
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