Hemodynamics

• What is another function of the cardiovascular system?

  Transport of nutrients
• What is a function related to waste in the cardiovascular system?

  Removal of wastes
• How does the cardiovascular system communicate for infection control?

  Through white blood cells (WBC)
• What do cells fundamentally need for their function?

  • Nutrient delivery
  • Waste removal
• Why is nutrient delivery and waste removal straightforward in single-cell organisms?

  Because they have direct access to their environment
• What is required for nutrient delivery and waste removal in multicellular organisms?

  The development of a respiratory and cardiovascular system
• What do Fick's laws of diffusion describe?

  The rate of diffusion is dependent on four variables
• What does Js represent in Fick's laws of diffusion?

  The rate of diffusion
• What is Js proportional to according to Fick's laws?

  Concentration gradient (ΔC)
• What is Js proportional to besides concentration gradient?

  Surface area available (A)
• What is Js inversely proportional to?

  Diffusion distance (Δx)
• What does solute diffusivity (D) depend on?

  Size, solubility, etc.
• What is the formula for Js?

  Js = -D A ΔC / Δx
• What is the distribution of cardiac output in the body?

  • Liver/GI: 25%
  • Kidney: 20%
  • Brain: 13%
  • Other: 10%
  • Heart: 4%
• What is the distribution of oxygen consumption per tissue?

  • Liver/GI: 30%
  • Brain: 18%
  • Other: 14%
  • Skin: 2%
  • Skeletal Muscle: 20%
• What is the approximate cardiac output for a normal adult at rest?

  1. 6 L/m
• How long does it take for a red blood cell to circulate in the body?

  Under 1 minute
• What type of circulation is systemic circulation?

  A high pressure circulation
• What type of blood does pulmonary circulation carry?

  Deoxygenated blood
• What is the driving force of blood circulation?

  The pressure gradient created by the heart pumping
• How many times does the heart beat approximately in a day?

  Approximately 100,000 beats
• What is the mean arterial pressure (MAP) in systemic circulation?

  Approximately 100 mmHg
• What is the significance of the thick layer of smooth muscle in arteries?

  It allows them to withstand high pressures
• What role do elastin fibers play in arteries?

  They provide elasticity
• What happens to arteries as we age?

  They get stiffer and less compliant
• What is the function of veins in the cardiovascular system?

  They carry blood back to the heart
• Why do veins have thinner walls compared to arteries?

  Because they operate in a low pressure system
• What is the compliance of veins compared to arteries?

  Veins have x20 compliance of arteries
• What is the site of nutrient exchange in the cardiovascular system?

  Capillaries
• What type of cells make up the walls of capillaries?

  Single layer of endothelial cells
• What are the three types of capillaries based on endothelial cell arrangement?

  Continuous, fenestrated, and sinusoidal

  
• What is the primary function of continuous capillaries?

  To restrict movement of substances
• What is the primary function of fenestrated capillaries?

  To allow larger molecules to leave the blood
• What is the primary function of sinusoidal capillaries?

  To allow for the passage of large molecules
• What is the difference in diffusion for lipid-soluble and water-soluble substances in capillaries?

  Lipid-soluble substances diffuse directly across the cell membrane
• What is osmosis?

  Movement of solvent to balance solute concentration
• What does osmotic pressure depend on?

  It is proportional to the osmolality
• What does Starling's hypothesis state about fluid flow out of capillaries?

  It depends on the balance of hydrostatic and oncotic pressures
• What is the hydrostatic pressure in capillaries?

  Approximately 25 mmHg
• What is the colloid osmotic pressure (COP) in capillaries?

  Approximately 26 mmHg