NAJEEB Hemodynamics Part II Flashcards
Formula of Velocity
Q (flow) / PI r^2
Total diameter from capillaries to vena caval system progressively (increasse/ decrease)
DECREASE
Velocity in inversely proportional to the
Cross sectional area through which blood is flowing.
As blood passes through the arterioles what happens to flow?
Pressure drops trying to overcome the resistance found in arterioles
Smallest branch of arteries
Arterioles
Capillaries role ( main )
Exchange vessels
Diameter of aorta vs ALL ARTERIOLES DIAMETER ADDED together, capillaries, etc
Diameter of aorta is large, but All ARTERIOLES DIAMETER ADDED TOGETHER IT IS LARGER than aorta. All CAPILLARIES added together, LARGER than arterioles and arteries.
As blood gets to the capillaries what occurs?
Gas exchange Pick up O2 from alveoli, Release CO2 to alveoli
Cross sectional area from aorta, arteriole to CAPILLARIES progressively
INCREASE
Point of maximum resistance to systemic circulation
Arterioles
Veins are called_______vessels
Capacitance vessels. Venous side capacitance is high
Cross sectional area from CAPILLARIES to VENA CAVA progressivel
DECREASE
Veins vs ARTERIES: PRESSURE
Veins low pressure
Arteries High pressure
2 advantages of arterioles
THICK-walled
Have A LOT OF SMOOTH MUSCLES
Veins vs ARTERIES: Blood
VEINS :Getting UNoxygenated blood from exchange vessels
ARTERIEs; Providing oxygenated blood to exchange vessels
What is the pulse pressure?
Difference between systolic and diastolic BP
Velocity of blood flow : what is it
Velocity of blood as it moves through systemic circulation
% of CO going to coronary
5%
Blood in arteries is under ____PRessure, therefore we call it ______Volume
high ; STRESSED volume
Pressure in pulmonary capillaries is
8 mmHg
Velocity of is ____in aorta _____In arteries ______ in arterioles ________in capillaries
High; lower; even lower, LEAST
Veins vs ARTERIES: Volume
Vein high volume
Arteries low volume
Capillaries come together to form
venules
Velocity is proportional to
Blood flow
Beta 2 adrenergic receptors on which bed
Musculoskeletal
Capilaries is about _____
30mmHg
Flow to large surface area, what happen to velocity?
decrease
More metabolically active tissue (like during exercise)How do arterioles react?
They dilate so that more blood can get to the tissues. Increase metabolic vasodilators release
Sympathetic OUTFLOW or OVERFLOW means there is
Arteriole constriction in renal, splanchnic and cutaneous
Stimulates beta 2 on musculoskeletal leading to dilation
Veins and blood
70% of BV is in veins
Pressure in LV
0 during diastole
120 during systole
Capillaries role
Exchange vessels
Systemic venous side type of blood
unoxygenated
Arterioles richly innervated by
Sympathetic (Alpha-1 adrenergic )
How do you calculate MAP?
Diastolic + 1/3 systolic BP
Pressure in major ELASTIC arteries
120
80
MAP 93mmhg
Total diameter of venules is more/less than capillaries
less
IF venous smooth muscle dilate (remember they are large capacitance vessels, MEANING there is VENOUS VASODILATION , what happens to UNSTRESSED VOLUME?
Unstressed volume INCREASED , venous return reduced, STRESSEd volume DECREASE
Should the pressure in the RA should lower or higher than the pressure in the caval system?
The pressure should be lower in the RA, because if the pressure is higher then blood would not be able to drain into the RA.
Alpha 1 adrenergic receptors on which bed
splanchnic
Renal
Cutaneous
Venous smooth muscle also have
sympathetic nerve supply meaning that they can constrict and dilate
Good thing about major AORTA arteries is that they are
Elastic , Systole stretch, diastolic relaxes , and recoils inward
Total diameter from large arteries to capillaries progressively (increasse/ decrease)
INCREASE
PA diastolic pressure is
8 mm Hg
Blood in veins is under _____Pressure, therefore we call it ______Volume
low: unstressed volume
Veins vs ARTERIES: lumen and wall describe
veins larger lumen, thin walled
Arteries smaller lumen, THICK WALL
Pressure gradient from systemic circulation to LA:
93 to 0 mmHg
Pressure gradient from pulmonary circulation to RA:
15 mmHg to 5-8 mmHg
RV diastolic pressure is _____ and systolic pressure is about
0; 25 mmHg (remember LV systolic is 120mmHg)
Pressure in venules is
15 mmHg (pressure is lower to allow blood to flow from capillaries to veins)
Efferent brings blood
Away from the glomerulus
From aorta to arteries to arteriole to venous
There is a PROGREssive decreASE in individual vessels diameter, but collectively bigger
Greatest resistance to systemic flow is
ARTERIOLES
By the times blood gets to the caval systme what is the presure?
4-5 mmHg
Pressure in LA
5-8 mmHg
By the times blood gets to the caval system what is the presure?
4-5 mmHg
Pressure in pulmonary veins
5 mmHg
Afferent brings blood_______and the diameter is ______
To glomerulus (DIAMETER IS larger)
Increase the cross sectional area will do what to blood flow?
decrease
MAP for 120/80
93 mmHG
What is velocity?
rate of LINEAR Displacement of blood per unit of time in the circulatory system.
From major arteries to organs
Arteries
Arterioles
Capillaries
Why is Glomerular capillaries so high at 50mmHg
Because it is located between 2 arterioles, Afferent (towards) EFFERENT (away)
Concept: IF venous smooth muscle constrict (remember they are large capacitance vessels, MEANING there is VENOUS VASOCONSTRICTION , what happens to UNSTRESSED VOLUME?
Unstressed volume is decreased
Unstressed volume is shifted to the heart, and through heart to ARTERIOLE SIDE, then becomes STRESSED VOLUME . Stress volume INCREASED
% of CO going to GI
15%
Upon blood coming from the caval system, into the RA, pressure in the RA is usually close to
0
Most Capilaries is about _____except ____
30mmHg
Veins vs ARTERIES: lumen and wall describe
veins larger lumen, thin walled
Arteries narrow lumen, THICK WALL
PA systolic pressure is similar to RV pressure of
25mmHg
Venous system :% of total blood
70%
