Blood Vessels
Circulatory System
Blood Vessels
Fundamentals:
- Vessels that segregate and contain the body fluid blood
Types:
Concepts:
- Comparison of Blood Vessels
- Arteries; Capillaries; Veins
- Total Cross Sectional Area - 5cm^2; 3000cm^2; 7cm^2
- Blood pressure (mmHg) - 80-120; 25; 0-25
- Velocity - 30 cm/s; 2 cm/s; 20 cm/s
- Volume of blood - 16-20; 5-7; 50
- Walls - Thick & Strong; Thin; Thin;
- Valves - NO; NO; YES
- Poisuille's Law
- Radius, length, change in pressure, viscocity are related to the flow rate
- 1)Flow rate is dependent on the radius of the vessel
- 2)Flow rate is inversely dependent of the length of vessel
- 3)Flow rate is inversely dependent of the viscocity of the solution
- 4)Flow rate is dependent on the change of pressure provided by the heart's contraction
- Blood Transport of Nutrients and Wastes
- Nutrients: Biomolecules
- Wastes (CO2, ammonia, urea) - enter the blood stream through their conc gradient
- Diffusion and Fick's Law
- Process by which molecules randomly move from one place to the next
- Dependent on
- Temperature
- Molecular weight
- Velocity
- 1)Diffusion is dependent on the diffusion coefficient
- 2)Diffusion is dependent on the area of interest
- 3)Diffusion is dependent on the concentration gradient
- 4)Diffusion is independent on the distance
- Osmosis
- Hydrostatic Pressures - difference in volume between the external and internal fluids
- PH2O is greater than the osmotic pressure
- Oncotic/Osmotic Presures - amount of pressure that stopped osmosis
- The difference in levels of water through a permeable membrane
- The pressure that draws fluid inward into the blood stream
- Proportional to the number of dissolved molecules
- There is a net difference in the fluid from the capillaries of
the interstitial space that eventually pulls it to the lymphatic
capillaries Lymphatic System
