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CT Blood Vessel Revi
Blood Vessel Review
Question | Answer |
---|---|
What are the 3 layers of blood vessel walls? | Tunica Intima; Tunica Media, Tunic Externa |
Tunica Intima | inner layer |
Tunica Media | smooth muscle layer (responsible for vasoconstriction and vasodilation) |
Tunica Externa | outer layer |
Basic features of arteries | carry oxygenated blood away from heart (except PA); thicker smooth muscle layer than veins; more elastic than veins; smaller lumen than veins |
Basic features of arterioles | Deliver blood to capillaries; greater influence n BP than arteries; |
Basic Features of capillaries | Microscopic, Exchange of gases, nutrients + wastes |
What are the different types of capillaries | Continuous; Fenestrated; Discontinuous |
Continuous capillaries | |
Fenestrated capillaries | |
Discontinuous capillaries | |
Basic Features of venules | |
Basic features of veins | Carry deoxygenated blood from body to heart (Except PVs) |
Basic features of venules | formed by several capillaries |
What is a portal vein? | vein that carries blood from one venous system to another venous system |
Which blood vessels have the most influence on BP? | Arterioles |
What is capillary filtration | the movement of water and solutes into interstitial fluid at the arterioler end of capillary |
What is hydrostatic pressure? | BP inside capillary, caused by LV contraction |
What is blood colloid osmotic pressure? | pressure of fluid due to its concentration of solutes/ proteins |
How does filtration occur? | when hydrostatic pressure is higher than osmotic pressure, water moves into the blood |
What is capillary reabsorption? | water moves back into the venule end of the capillary |
How does capillary reabsorption occur? | because osmotic pressure is higher than hydrostatic pressure (BP is lower than osmotic pressure) (osmosis and diffusion) |
What is edema? | excess fluid in the interstitial fluid |
How does edema occur? | from too much capillary filtration and not enough reabsorption (fluid stays in tissue spaces) |
What are the factors influencing venous return? | left ventricular systole (BP); skeletal muscle pump (muscle compression of veins); respiratory pump |
What is blood pressure? | Pressure exerted by the blood on the walls of the blood vessels |
How is blood pressure created? | left ventricular systole |
What happens to BP as blood move through the circulatory system? | decreases: aorta 100-120mmHg; Arterioles 60-70; capillaries 35-15mmHg; venules 15mmHg; veins 5-6mmHg; vena cava 0 |
Pulse Pressure | Difference between systolic and diastolic BP 130/60 =70 |
MABP (mean arterial blood pressure) | pressure that's averaged over an entire cardiac cycle- represents the pressure that pushes blood through the entire system |
What are factors that affect BP? | resistance; viscosity; turbulence |
Why does capillary filtration happen? | because capillary hydrostatic pressure (BP) is higher than the blood colloid osmotic pressure |
capillary hydrostatic pressure is | Blood pressure |
Which plasma protein are we concerned about? | albumin |
What happens on inhalation | diaphragm moves down, abdominal veins compressed; blood gets pushed up towards RA |
What happens on exhalation | diaphragm moves up; compression on abdominal veins decreases; blood gets pulled up from legs; veins help to prevent backflow |
Normal MABP | 70-110mmHg |
What is the number that indicates inadequate perfusion? | 60 or less mmHg |
resistance | the more length there is the more resistance; the smaller the diameter the more resistance you have |
viscosity | increased viscosity = increased resistance |
turbulence is: | a disruption in flow; increases resistance |