Chap 10-12 Arterial and Venous Physiology Flashcards
Name the superficial veins of the LE.
GSV SSV confluence of superficial inguinal veins intersaphenous veins post accessory GSV
Name the superficial veins of the UE.
cephalic
basilic
What is dynamic pressure?
Dominates in supine position
pressure generated by cardiac pumping
majority dissipated before capillary bed
blood flow along gradient
What is hydrostatic pressure?
dominates in upright position
weight of column of blood below right atrium
return of blood to heart must overcome this pressure
Which muscle pump is the most important for blood return? and how does the muscle pump work?
calf
generates high pressure during muscle contraction propels blood forward
during relaxation, valves close preventing reflux
negative pressure generated by valve closure creates negative pressure which draws blood from superficial system
What is venous compliance?
change in blood volume that occurs for each unit change in transmural pressure in a segment of vein
compliance is the slope of the capacitance curve
What is venous capacitance?
relationship b/w pressure and volume at a given level of smooth muscle tone
How does transmural pressure relate to venous volume?
transmural P is the difference b/w pressure acting to expand vein and pressure acting to collapse vein
high transmural pressure = high venous volume
15mmhg increase can = 25-% increase in volume
What law dictates passive flow of blood in/out of organs?
ohm’s law Pdiff = F x R
What factors contribute to venous return?
pressure gradients muscle pumps venous valves movement of diaphragm changes in intrathroacic/intraabdominal pressure (less for UE)
What are the types of valvular anomalies that lead to valvular incompetence?
Type I elongated and atrophic cusps
Type II expanded and depressed commissures with cusps changes
Type III cusps with other deformities
Type IV absent cusps
type II most common
What are ranges for venous filling index?
7 associated with venous ulcers
How does venous HTN occur?
presence of incompetent valves/obstruction, blood refluxes distally during muscle relaxation
re-establishes the hydrostatic column
periph venous P rises b/w contraction and HTN occurs
How do ambulatory venous pressure relate to incidence of venous ulceration?
80, 80
What are symptoms of post-thrombotic syndrome?
LE pain
edema
hyperpig
stasis ulcer
