Term
| Layers of vessels (except capillaries) and function |
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Definition
-Tunica adventitia: fibrous connective support (Outside layer)
-Tunica media: smooth muscle that constricts and relaxes
the control diamete
-tunica intima: elastic layer that joins the media to the endothelium (smooth inner lining & prevents platelet adherence and blood clotting) |
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Term
| Arteries and Arterioles characteristics |
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Definition
-Think walled (relative to veins)
-elastic fibers allow stretch during systole and recoil during diastole
-Arterioles-determine PVR (peripheral vascular resistance)
~ thick medial layer- serve as resistance vessels
~ Increased sympathetic stimulation -> vasoconstriction
~ Decreased sympathetic stimulation (parasympathetic)-> vasodilatation |
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Term
| Types of arteries and functions |
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Definition
Large arteries-> transport of blood
Medium-sized arteries-> distribute blood flow to various organs and tissue of body
Small arteries and arterioles -> regulate capillary blood flow (capillary beds are cut off and some open up based on metabolic needs) |
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Term
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Definition
-thin walled, yet muscular
-distensible and collapsible (stretchable)
-large capacity for blood
-Sympathetic nervous system
-low pressure 0-10 mmHg
-contains valves to oppose gravity |
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Term
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Definition
-single endothelial cell surrounded by basement membrane (thin so things can diffuse)
-connect arterial and venous circulation
-Intracellular junctions-pores |
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Term
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Definition
Transport fluid from interstitial spaces
-25-50% of total circulating blood proteins per day
-located: subcutaneous tissues and submucosa |
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Term
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Definition
lymph vessels pick up ISF and return to blood
lymph nodes-filter fluid; phagocytosis of foreign material |
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Term
| Effects of Blood vessel disease: Arterial disorders |
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Definition
-decreased blood flow to the tissues
-impaired delivery of oxygen and nutrients |
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Term
| blood disease: Venous disorders |
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Definition
-interference with the outflow of blood from the capillaries
-interference with removal of tissue wastes and return of blood to the heart |
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Term
| Blood flow requires that: |
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Definition
-arterial pressure is greater than venous pressure
-arterial, venous, and capillary pressure are greater than pressure surrounding vessels |
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Term
| Blood flow is determined by: |
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Definition
cardiac output (CO=SV x HR)
-a pressure difference between two ends of a vessel (higher pressure at arterial end, lower pressure at venous end)
-resistance which must be overcome to move blood through the vessel (friction)
- longer vessel is slower- heart has to pump to over come resistance
- diameter->small -> more resistance |
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Term
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Definition
velocity is inversely proportional to the cross-sectional area of the vessel or vessels
-velocity is higher in the large vessels than in the capillary bed
-slower velocity--> more time for capillary exchange |
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Term
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Definition
RELATED TO CROSS-SECTIONAL AREA
-blood flow is faster in the aorta and slower in the capillaries |
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Term
| Laminar and turbulent flow |
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Definition
Laminar (smooth)
Turbulent (mixed up)
-flow is faster in center of vessel
- Turbulence disrupts flow (clots in large vessel)
-Causes of turbulence
~obstruction (atherosclerosis, aneurysm, compression, etc)
~ high velocity, low viscosity
~ Large vessels
~ Vessel branching
- predisposition to clotting |
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Term
| Velocity of flow increases when |
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Definition
| -Velocity of flow increases when the radius decreases |
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Term
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Definition
- as the velocity of a fluid increases, its pressure decreases
- the pressure in a flowing fluid is lowest where its speed is greatest |
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Term
| Factors contributing to disturbance in blood flow |
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Definition
-pathologic changes in vessel wall (atherosclerosis- hardening of arteries and vasculitis-inflammation of vessels)
- acute vessel obstruction due to thrombus, embolus, or vasospasm (raynaud's phenomenon)
-abnormal vessel dilation (arterial aneurysms or varicose veins)
-compression of blood vessels by extravasular forces (tumors, edema etc) |
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Term
| Peripheral Vascular Disease (PVD) |
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Definition
general term used for vascular disease in the extremities
blood flow problems to the extremities |
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Term
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Definition
Blood Clot
-blood clot in vessel or heart chamber
-reduces or blocks blood flow and causes turbulence |
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Term
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Definition
-ARTERIAL-pain, coolness, ulceration, cyanosis (blue color of skin because of lack of oxygenated blood)
-Venous-tenderness, swelling, warmth |
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Term
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Definition
More DANGEROUS
- a clot traveling within the blood stream
-Thromboembolus- thrombus that was dislodged
-From left side of the heart-CVA-STROKE
-From right side of hte heart-Pulmonary embolus |
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