CPRS 29 30: Blood Flow and Blood Pressure Flashcards
What is the formula for calculation of Mean Arterial Pressure
By stroke volume, heart rate, total peripheral resistance
Stroke volume x Heart Rate x Total Peripheral Resistance
Laplace equation: How to calculate tension?
Transmural pressure x (Vessel radius/vessel wall thickness)
Which section in the blood vessels have the highest resistance?
Arterioles
NOT capillaries
Name 3 assumptions in resistance calculation
- Vessel is ______ and _____ and has constant _____
- Blood flow is ________ and _______
- Blood has constant _________
Name 3 assumptions in resistance calculation
- Vessel is straight, cylindrical and have constant radius
- Blood flow is laminar and steady
- Blood has constant viscosity
Why does veins have higher compliance (lower elasticity) than arteries?
Because arteries have thicker ___________ making it more difficult to change shape
After aging of arteries, the arterial wall gets even thicker. The artery will be _______ elastic (less or more)
Why does veins have higher compliance (lower elasticity) than arteries?
Because arteries have thicker collagen fibres/ elastic fibres making it more difficult to change shape
After aging of arteries, the arterial wall gets even thicker. The artery will be more elastic (less or more)
Normal Arteries
- Systole: After blood ejection from the left ventricle, small portion of blood leaves the aorta immediately. Some remains in the aorta and stretch the aorta, which increases the aortic pressure.
-Diastole: After elastic recoil, there is minor backflow of blood that closes the _______ and most blood are pushed towards downstream
Rigid Arteries
- Systole: Volume of blood equal to the entire ________ will leave the aorta which increases the aortic pressure by a lot
- Diastole: Blood flow will _____________
Normal Arteries
- Systole: After blood ejection from the left ventricle, small portion of blood leaves the aorta immediately. Some remains in the aorta and stretch the aorta, which increases the aortic pressure.
-Diastole: After elastic recoil, there is minor backflow of blood that closes the aortic valve and most blood are pushed towards downstream
Rigid Arteries
- Systole: Volume of blood equal to the entire stroke volume will leave the aorta which increases the aortic pressure by a lot
- Diastole: Blood flow will cease
Name the systolic and diastolic pressure range for the following
Normal:
Prehypertension:
Hypertension Stage 1:
Hypertension Stage 2:
Name the systolic and diastolic pressure range for the following
Normal: <120; <80
Prehypertension: 120-139; 80-89
Hypertension Stage 1: 140-159; 90-99
Hypertension Stage 2: >160; >100
Name the vascular shunt when all the precapillary sphincters are closed/ fully contracted
Metarteriole
For the smooth muscles, what are the dense body made of?
Vimentin and Desmin
What are the details of process during the smooth muscle contraction process?
- Increase Ca2+ due to increase _________ and increased influx of Ca2+
- More Ca2+ binds to __________
- __________ binds and activates more ________
- More MLCK _______________
- Increase myosin heads binding to actin facilitating contraction
What are the details of process during the smooth muscle contraction process?
- Increase Ca2+ due to increase CICR and increased influx of Ca2+
- More Ca2+ binds to Calmodulin (CaM)
- Ca2+-CaM binds and activates more MLCK
- More MLCK phosphorylates more myosin
- Increase myosin heads binding to actin facilitating contraction
What are the details for the smooth muscle relaxation process?
- Decrease in Ca2+ due to __________ and _____________
- Decrease Ca binding to ________
- Decreased formation of __________ complex
- Decrease MLCK which___________
or
Phosphorylates _________ so it becomes less sensitive to be activated by _______________
What are the details for the smooth muscle relaxation process?
- Decrease in Ca2+ due to Ca2+ pumped in SR by SERCA and Ca2+ pumped out by Ca2+ ATPase
- Decrease Ca binding to Calmodulin (CaM)
- Decreased formation of Ca2+-CaM complex
- Decrease MLCK which phosphorylates less myosin
or
Phosphorylates MLCK so it becomes less sensitive to be activated by Ca2+-CaM
By T = Transmural pressure x (Radius/thickness of vessel)
When blood pressure increases, what will happen
When vessel radius reduces, what will happen
By T = Transmural pressure x (Radius/thickness of vessel)
When blood pressure increases, what will happen
The transmural pressure increases, tension increases
When vessel radius reduces, what will happen
Tension reduces
Consider Nitric Oxide - Endothelium derived vasoconstrictor/ vasodilator? - Agonists? - Mechanism of action: Activates \_\_\_\_\_\_\_\_ More \_\_\_\_\_\_ becomes \_\_\_\_\_\_ Increase activity of \_\_\_\_\_\_\_\_\_\_ Increase phosphorylation of \_\_\_\_\_\_\_\_\_ Increase \_\_\_\_\_\_ Ca2+ sequestration by SR Smooth muscle relaxation
Consider Nitric Oxide - Endothelium derived vasodilator - Agonists: Acetylcholine, Histamine - Mechanism of action: Activates guanylyl cyclase More cGTP becomes cGMP Increase activity of Protein Kinase G Increase phosphorylation of MLCK Increase SERCA Ca2+ sequestration by SR Smooth muscle relaxation
Consider Prostaglandin I2 - Endothelium derived vasoconstrictor/ vasodilator? - Mechanism of action: Activates \_\_\_\_\_\_\_\_ More \_\_\_\_\_\_ becomes \_\_\_\_\_\_ Increase activity of \_\_\_\_\_\_\_\_\_\_ Increase phosphorylation of \_\_\_\_\_\_\_\_\_ Increase \_\_\_\_\_\_ Ca2+ sequestration by SR Smooth muscle relaxation
Consider Prostaglandin I2 - Endothelium derived vasodilator? - Mechanism of action: Activates adenylyl cyclase More cATP becomes cAMP Increase activity of Protein Kinase A Increase phosphorylation of MLCK Increase SERCA Ca2+ sequestration by SR Smooth muscle relaxation
Consider Endothelin-1 - Endothelium derived vasoconstrictor/ vasodilator? - Mechanism of action: Activates \_\_\_\_\_\_\_\_ Increase \_\_\_\_\_\_ level in cytoplasm Increase \_\_\_\_\_\_ bind on \_\_\_\_\_\_ receptors in SR Increase Calcium release by SR Increase \_\_\_\_\_\_ activity Increase smooth muscle contraction
Consider Endothelin-1 - Endothelium derived vasoconstrictor? - Mechanism of action: Activates Phospholipase C (PLC) Increase IP3 level in cytoplasm Increase IP3 bind on IP3 receptors in SR Increase Calcium release by SR Increase MLCK activity Increase smooth muscle contraction