Chapter 22 : physiology and hemodynamics Flashcards Preview

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Flashcards in Chapter 22 : physiology and hemodynamics Deck (17):
1

arteries and veins carry

the same amount of blood

2

____ shape of venous walls offers more resistance than _____ shape

flattened shape offers more flow resistance than circular shape

3

when distended, the cross section of vein is how much larger than the artery

3-4 times as large

4

the extra pulmonary veins carry about ____ of the blood in the body

2/3

5

the shape of the veins are determined by

transmural pressure
pressure within the vein versus pressure outside of the vein

6

low transmural pressure

low volume of blood results in dumbbell shape

7

high transmural pressure

high volume results in circular shape

8

hydrostatic pressure equation

HP = PGH

P= specific gravity of blood
G= acceleration due to gravity
H= distance from the heart

9

HP at ankle supine

presumed to be 0mmHg

10

HP at ankle standing

100 mmHg

11

raised arm HP

-50mmHg

12

what helps propel blood towards the heart

muscle contraction

13

effective calf muscle pump

blood moves from superficial system to deep system
competent valves prevent reflux
venous volume and pressure decreases
venous return to heart increase

14

ineffective calf muscle pump

incompetent valves cause reflux
venous volume and pressure increases
results in venous pooling and ambulatory venous hypertension

15

inspiration

decrease intra-thoracic pressure
increase blood flow from upper extremities
increase intra-abdominal pressure
decrease blood flow from lower extremities

16

exhalation

increase intra-thoracic pressure
decreases blood flow from upper extremities
decrease in intra-abdominal pressure
increases blood flow from lower extremities

17

valsalva maneuver

intra-thoracic and abdominal pressure increase
all venous return halted