Circulatory - Intro + Starling Fluid Flashcards
What causes BCOP to reabsorb?
- It is caused by the osmotically-active large MW proteins that are compartmentalized in the capillaries.
- These proteins pull water/fluid back into the capillary network
- Approximately how wide are endothelial clefts?
- What size molecules can generally pass through these clefts?
- 4 nm
- molecules up to 20,000 daltons - ie Na+, glucose, oxygen
Under normal physiologically conditions, what 2 pressures should be neglible?
Interstitial Fluid Hydrostatic Pressure (IFHP) and Interstitial Fluid Colloid Osmotic Pressure (IFCOP)
- What type of capillaries would you expect to find in the Liver?
- What type of capillaries would you expect to find in the Skeletal Muscle?
- What type of capillaries would you expect to find in the Intestine/Kidney?
- Sinusoidal - Liver makes large proteins like albumin and puts it into blood stream
- Continuous - skeletal muscle only needs small molucels like Na Glucose and Oxygen.
- Fennestrated - need a little bit more room to fit stuff in…
What 2 pressures promote filtration?
Blood Hydrostatic Pressure (BHP) and Interstitial Fluid Colloid Osmotic Pressure (IFCOP)
What is the equation for “Ficks Law in Capillaries?”
What does each variable stand for?
J = PS (Cc - Cif)
- J - flux of a substance across capillary wall per unit time
- P - permeability of capillary to the substance
- S - Surface area of capillary
- CC - Concentration of substance inside the capillary
- Cif - Consenctration of substance in the interstitial fluid
Interstitial Capillaries have a BHP of ~ 15 mmHg. Would this favor filtration or resorption?
Resorption
Which blood vessel has the largest surface area? Why is this important?
- Capillaries
- Capillaries are where we exchange gas/nutrients to tissues. We need a large area to perform such an important task.
In normal physiological conditions, Does BHP increase or decrease as it goes from arteriolar end to venular end?
What pressure values does the BHP have from A –>V?
- Decreases
- A = 30 mmHg –> 25 mmHg (in the middle area) –> 15 mmHG
What does it mean that small molecules are flow limited in capillaries?
- Small molecules like Oxygen/Glucose normally diffuse out of capillaries with ease becuase their concentration is greater inside the capillary.
- This concentration is maintained by blood flow…so the concentration of small molecules is always kept at a high level in capillaries.
T/F
Veins are the only vascular system (Arteries/Capillaries being the other systems) to exhibit one way movement of blood?
False
- Veins most likely function in one way blood movement..due to valves
- However, arteries and capillaries also exhibit one movement lf blood.
What are the 4 types of capillaries? List them in order of most restrictive to least restrictive…
- Blood Brain Barrier Capillaries
- Continuous Capillaries
- Fenestrated Capillaries
- Sinusoid Capillaries
Blood velocity and Cross Sectional area are [] propotional…
Inversely
- What possess a stronger opposition to blood flow?
- Arteries
- Arterioles
Arterioles
What molecular component of blood carries CO2 in the blood stream?
Bicarbonate
Under normal Physiological conditions, what 2 pressure influence the net filtration pressure?
BHP (blood hydrostatic pressue) and BCOP (blood colloid osmotic pressure)
What does “Capacitance” mean in circulation?
The ability to store blood
What are the 4 main pressures of circulation?
- Blood Hydrostatic Pressure (BHP)
- Interstitial Fluid Hydrostatic Pressure (IFHP)
- Blood Colloid Osmotic Pressure (BCOP)
- Interstitial Fluid Colloid Osmotic Pressure (IFCOP)
[] is the net movement of water and dissolved solutes from the plasma fluid compartment into the interstitial fluid.
Filtration
What 2 pressures promote reabsorption?
Interstitial Fluid Hydrostatic Pressure (IFHP) and Blood Colloid Osmotic Pressure (BCOP)
T/F
Venodilation, in times of need like hemorrhage, will push blood volume through the veinous system to areas in need.
False
Venoconstriction will push blood through the veins in times of need.
Reabsorption is the net movement of water and dissolved solutes from the [] into the []
From the Interstitial into the Blood.
What are arteries the main vasculature system to control vasconstriction/vasodilation?
Becuase arteries are surrounded by a much thicker layer of smooth muscle. Smooth muscle contracts/relaxes to cause vaso-constriction/dilation
Kidney Glomerular Capillaries have a BHP of ~ 50 mmHg, does this promote filtration or resorption?
Filtration
What is the equation for the NFP - Net filtration pressure? What does each variable stand for?
NFP = [(Pc + πif) - (Pif + πc)]
- Pc - Capillary Hydrostatic Pressure (BHP)
- πif - Interstitial Fluid Colloid Osmotic Pressure
- Pif - Interstitial Fluid Hydrostatic Pressure
- πc - Capillary Colloid Osmotic Pressure (BCOP)
What structures house the largest capacity of blood in the body?
Capacitance Vessels - Veins and Venules
Why are proteins diffusion limited in capillaries?
Their permeability factor is very low so their flux is very low.
Red blood cells, white blood cells, and large MW proteins like Albumin can/cannot pass the endothelial clefts?
Cannot
What happens in the following scenarios?
- BCOP > BHP
- BHP> BCOP
- Net resorption
- Net Filtration
What are the 2 types of arteries?
Elastic Arteries (like the Aorta)
Distributing Arteries
T/F
Gas exchange primarily happens in the capillary network?
True
What causes the BCOP to raise from 18 mmHg at the arteriole end of a blood vessel to 25 mmHg at the mid point of the blood vessel and then back to 18 mmHg at the venular end?
- At the arteriole end - we have net filtration of fluids out of the capillary due to BHP. This would cause the remaining capillary fluid to have an increased concentration/BCOP of proteins.
- This increased concentration pulls water back into the capillary….therefore decreasing the concentration/BCOP back down to 18 mmHG at the venular end
[]% of blood is not reabsorbed but sent to the lymph system?
15% of blood
