bsci202 lab practical 1

• where is the blood found?

  heart, blood vessels, capillaries, all throughout the body
• what type of tissue is blood and what is it composed of? (also how much of your body weight is blood?)

  it is a connective tissue that is composed of plasma (55%), buffy coat (<1%), and erythrocytes (45%)

  • around 8% of body weight
• plasma: 90% water and 10% solutes

  • composed of albumin, globulin, clotting proteins, nonprotein nitrogen substances, organic nutrients, electrolytes, regulatory substances, respiratory gases
• albumin: maintains osmotic pressure and controls water balance between interstitial fluid and blood, serves as a transport protein, buffer for changes in pH
• globulin:

  • alpha and beta: transport proteins for metal ions, cholesterol, complement proteins
  • apoproteins: transport cholesterol, forming lipoproteins
  • gamma (y) globulins: antibodies
• clotting proteins: fibrogen, prothrombin, and other proteins used for coagulation
• what are the formed elements?

  erythrocytes, leukocytes, platelets
• erythrocytes: use hemoglobin to carry oxygen to tissues throughout the body (most abundant)
• leukocytes: have many different immune functions and can travel out of blood vessels into tissues by diapedesis

  • granulocytes: neutrophils, eosinophils, basophils
  • agranulocytes: lymphocytes, monocytes
• platelets: critical in blood clotting

  • originate from megakaryocytes and are cytoplasmic fragments
• leukocytes in order from most to least abundant: neutrophils, lymphocytes, monocytes, eosinophils, basophils (never let monkeys eat bananas)
• anemia: low rbc count caused by lack of iron
• aplastic anemia: bone marrow does not produce enough rbc's
• iron-deficiency anemia: erythrocytes are smaller
• hemolytic anemia: rbc's destroyed faster than made
• sickle-cell anemia: abnormal hemoglobin --> sickle shaped cells
• hemorrhagic anemia: caused by blood loss and is not detected by the hematocrit
• what is a hematocrit?

  test done to find your rbc percentage in your body
• how is a hematocrit performed and analyzed?

  • centrifuge a tube of blood
  • measure the total length of fluid and the RBC, WBC, and plasma
  • calculate percentage of each component of the blood
• what is a buffy coat?

  contains leukocytes and platelets (<1%)
• what factors can affect hematocrit values?

  leukocytosis, anemia, living in high altitude (higher hematocrit), dehydration (plasma % decreases)
• what are all the lymphoid organs?

  red bone marrow, spleen, thymus, tonsils, peyer's patches, appendix
• red bone marrow: lymphocyte production, b cells mature here
• spleen: filters blood and destroys worn out blood cells
• thymus: produces hormones to program lymphocytes
• tonsils: trap and remove bacteria and other foreign materials
• peyer's patches: capture and destroy bacteria in intestine
• appendix: reservoir for gut bacteria; may assist in b cell maturation
• what is lymph?

  fluid carried by lymphatic vessels that is pumped in a one-way system to move it back to the heart and back into the blood(skeletal muscle pump)
• b cells: replicates by binding to antibody to produce plasma and memory cells
• plasma cells: produce antibodies
• helper t cells: stimulates production of cytotoxic t cells and super activates b cells; also release cytokines
• cytotoxic t cells: attack virus-invaded body cells and cancerous cells
• regulatory t cells: slows or stops activity of b and t cells once infection is destroyed
• memory cells: generated from initial immune response and allows body to respond faster during the second exposure
• APC's (antigen presenting cells): macrophages, dendritic cells, b cells

  • engulfs antigen and displays fragments of it on its MHC I and MHC II on the surface of the cell
• antibody: 4 polypeptide chains (2 heavy, 2 light) and two functional areas (variable and constant)
• variable region of antibody: gives specificity to antigen-binding site
• constant region of antibody: same within the same class of antibodies
• antibodies inactivate things by: neutralization, agglutination, precipitation which enhances phagocytosis