cvs the blood vessel & hemodynamics

• What are the 5 main types of blood vessels?

  Arteries, arterioles, capillaries, venules, and veins
• What is the primary function of capillaries?


  They are the site of exchange between blood and interstitial fluid
• What is the tunica interna also known as?


  Tunica intima
• What role does the endothelium play in blood vessels?


  It is in direct contact with blood and plays an active role in vessel-related activities
• What is the tunica media composed of?


  Muscular and connective tissue
• How does the tunica media vary among different vessel types?


  It shows the greatest variation among vessel types
• What regulates the diameter of the lumen in blood vessels?

  Smooth muscle in the tunica media
• What is the function of the tunica externa?


  It helps anchor the vessel to surrounding tissue
• What is the characteristic of arteries regarding their walls?

  They have thick muscular-to-elastic tunica media
• What does high compliance in arteries mean?


  Walls stretch and expand in response to pressure without tearing
• What is vasoconstriction?


  A decrease in lumen diameter
• What is vasodilation?


  An increase in lumen diameter
• What are capillaries known as?


  Exchange vessels
• Why do capillaries lack tunica media and tunica externa?


  To facilitate the exchange of substances
• What is the primary function of venules?


  To collect blood from capillaries
• How do the structural changes in veins compare to arteries?


  They are not as distinct as in arteries
• What is the characteristic of veins regarding their walls?


  They have very thin walls in relation to total diameter
• What is the role of valves in veins?


  They aid in venous return by preventing backflow
• What is the largest portion of blood at rest found?

  In systemic veins and venules
• What is venoconstriction?


  A process that reduces the volume of blood in reservoirs
• What are the three basic methods of capillary exchange?


  Diffusion, transcytosis, and bulk flow
• What is the most important method for solute exchange in capillaries?

  Diffusion
• How do substances move during diffusion?


  Down their concentration gradient
• What substances move from blood to interstitial fluid during diffusion?


  Oxygen and nutrients
• What substances move from body cells to blood during diffusion?


  Carbon dioxide and wastes
• How can substances cross the capillary wall?


  Through intracellular clefts, fenestrations, or endothelial cells
• What is transcytosis?


  A method where substances in blood plasma are enclosed within pinocytotic vesicles
• What is bulk flow?


  A passive process where large numbers of particles move together in the same direction
• What is the significance of net filtration pressure (NFP)?


  It balances the pressures promoting filtration and reabsorption
• What is the formula for net filtration pressure (NFP)?


  NFP = (BHP + IFOP) – (BCOP + IFHP)
• What generates blood hydrostatic pressure (BHP)?


  The pumping action of the heart
• What is the average value of blood hydrostatic pressure (BHP) in capillaries?


  It falls from 35 to 16 mmHg
• What is blood colloid osmotic pressure (BCOP) due to?


  The presence of blood plasma proteins too large to cross the walls
• What is the average value of blood colloid osmotic pressure (BCOP)?


  Averages 36 mmHg
• What is the relationship between blood flow and cardiac output (CO)?


  Total blood flow is equal to cardiac output
• What is the formula for cardiac output (CO)?


  CO = heart rate (HR) x stroke volume (SV)
• What drives blood flow through tissues?

  Pressure differences that drive blood from higher to lower pressure
• What does higher resistance in blood vessels mean for blood flow?


  It means smaller blood flow
• What generates blood pressure?

  Contraction of ventricles
• What is systolic blood pressure (BP)?


  The highest pressure attained in arteries during systole