bsci202 exam 1 - blood

• components of the cardiovascular system: blood, heart, blood vessels
• blood: pumped from high to low pressure
• heart: pumps blood and creates pressures
• blood vessels: circulate blood between cells and heart
• functions of the cardiovascular system: distribution, regulation, protection
• how is distribution a function of the cardiovascular system?

  O2 to cells, CO2 to lungs, nutrients, hormones
• how is regulation a function of the cardiovascular system?

  it maintains tissue pH, blood volume, body temperature
• how is protection a function of the cardiovascular system?

  it prevents infection and blood loss
• what is the composition of blood?

  it is a connective tissue that consists of plasma (55%), a buffy coat (<1%), and erythrocytes (45%)
• what are the physical characteristics of blood?

  sticky, opaque, 3-5 times more viscous than water, scarlet color (O2 rich) and darker red color (O2 poor)
• what is the pH of blood?

  7.35-7.45
• what is the composition of plasma?

  90% water and 10% solutes
• what are the solutes in plasma?

  albumin, globulin (alpha and beta globulins, apoproteins, gamma (y) globulins), clotting proteins
• albumin: 60% of solutes, produced by the liver

  • maintains osmotic pressure and controls water balance between interstitial fluid and blood
  • serves as a transport protein
  • binds CA2+ and is a buffer for changes in pH
• globulin: 36% of solutes

  • alpha and beta globulins: produced by the liver (some are complement)
  • transport proteins for metal ions, cholesterol, complement proteins
  • apoproteins: transport cholesterol, forming lipoproteins
  • gamma (y) globulins: produced by lymphocytes and are antibodies
• clotting proteins: 4% of solutes, made by the liver

  • fibrogen, prothrombin, other proteins used for coagulation
  • net that captures platelets and rbc's
• what are the other 5 components of the plasma?

  nonprotein nitrogen substances, organic nutrients, electrolytes, respiratory gases, regulatory substances
• nonprotein nitrogen substances: recycled proteins
• organic nutrients: glucose, amino acids, vitamins
• electrolytes: maintain acid/base balance and osmotic pressure
• respiratory gases: O2, CO2, N2
• regulatory substances: enzymes and hormones
• what is the pH of plasma: 7.38 - 7.42
• what is the function of plasma: transport nutrients, subtances, proteins around the body because the formed elements are suspended in the plasma
• what is the structure of an erythrocytes?

  anucleate, biconcave disc (helps with gas diffusion)
• what is the function of erythrocytes?

  carry O2 and CO2
• why do men have a higher concentration of rbc's than women?

  testosterone enhances rbc production and estrogen suppresses it
• what is the structure of hemoglobin?

  heme + globin
• globin: 4 polypeptide chain and each chain binds covalently to heme

  • binds to CO2
• heme: porphytin ring with a central Fe2+, 4 hemes in 1 hemoglobin

  • each heme binds to 1 O2
• what is the function of hemoglobin?

  carries up to 4 O2 molecules, up to 20% of CO2 in the body, and buffers H+

  • only found in erythrocytes
• what is the process of erythropoeisis?

  the production of red blood cells from stem cells in the red bone marrow
• what happens during erythropoiesis?

  cell gets smaller, color turns from blue to red, organelles degraded and nucleus extruded, cell number increase from the mitosis
• how is erythropoiesis regulated?


  erythropoietin (EPO), a hormone produced by the kidney and liver cells in response to hypoxia (low O2)
• what does EPO do?

  increases the rbc production when released (classic negative feedback loop) and once O2 saturation rises, EPO secretion falls
• what are the necessary dietary components for erythropoiesis?

  iron, vitamin B12, folic acid, vitamin C, amino acids
• how are erythrocytes degraded?

  damaged, aged, or defective erythrocytes are removed from circulation by macrophages of the liver, spleen, and bone marrow
• how is the hemoglobin recycled during erythrocytes degration?

  heme --> iron, biliverdin (stercobilin (feces), urobilin (kidneys, pee))

  globin --> amino acids
• what is hemorrhagic anemia?

  reduced rbc numbers
• what is hemolytic anemia?

  rbc's destroyed faster than made