pg 350-359 Flashcards
https://drive.google.com/open?id=0B8uJUY-tie8GNFBXUmstbG9uODQ
https://drive.google.com/open?id=0B8uJUY-tie8GMHRtbno5dWpacUE
Greatest total area.
■ Large surface area.
■ Slowest velocity of an individual blood cell.
CAPILLARIES
Allows time for oxygen, nutrient exchange/diffusion
capp
Account for:
■ Largest drop in BP (~50% drop from arteries to arterioles).
■ Highest proportion of peripheral vascular resistance.
arterioles
Pressure decreases as blood moves through systemic circulation.
■ This pressure gradient is required for blood flow.
arterioles
blood vol
Most is held within the systemic venous circulation:
>60% in systemic veins.
■ >10% in systemic arteries.
■ <10% in arterioles and capillaries.
blood cvol
9% in pulmonary vessels.
■ 7% in heart.
blood vol
Ability to hold blood volume.
■ Act as a reservoir
capitance
Veins.
■ Capacitance vessels.
■ Dilate to accommodate blood volume.
■ Hold 50–60% of blood volume
In hypovolemia, veins/venules xxx
In hypovolemia, veins/venules constrict
Sympathetic mediated.
■ Compensatory.
In hypovolemia, veins/venules constrict
No clinical manifestations with 15–20% blood loss.
■ Helps maintain mean systemic filling pressure in the face of blood loss.
■ Preload is maintained with venous constriction
hypovolemia
Arterial constriction system has much xxx effect on mean systemic filling
pressure.
■ Arterial system contains relatively yyy amount of blood.
■ Arterial constriction zzz afterload.
Arterial constriction system has much less effect on mean systemic filling
pressure.
■ Arterial system contains relatively small amount of blood.
■ Arterial constriction increases afterload.
Capillaries do not constrict because they lack xx in their walls.
Capillaries do not constrict because they lack smooth muscle in their walls.
https://drive.google.com/open?id=0B8uJUY-tie8GZENTTFBoRmE1Rm8
https://drive.google.com/open?id=0B8uJUY-tie8GR1BLRU96WTd4S28
tPr
TPR (peripheral vascular resistance).
■ Vascular resistance of the systemic circulation.
■ Mean arterial pressure minus central venous pressure divided by the cardiac
output (MAP – CVP)/CO.
Tpr
Increases with sympathetic activation; arteriolar constriction.
https://drive.google.com/open?id=0B8uJUY-tie8GRlFfbmZjakJKRlU
https://drive.google.com/open?id=0B8uJUY-tie8GS0pBY1FvTXo5Uzg
Blood flow from systemic circulation into venous
circulation.
TPR
Blood flow from veins back into arterial system.
CO
Amount of blood in systemic veins.
compliance
BP = xxxx
■ Systolic pressure/diastolic pressure yy
BP = CO °ø TPR.
■ Systolic pressure/diastolic pressure (120/80).