Blood

Olivia Graves

Overall Characteristics

Components:
  • 55% plasma,
  • 45% red blood cells (RBCs),
  • <1% leukocytes (white blood cells or WBCs) and platelets (thrombocytes)


Blood Volume:
  • male: 5-6 liters
  • female: 4-5 liters


Blood is formed in red bone marrow and is controlled by the hormones erythropoeitin (RBCs) and lymphokins (WBCs) to determine what the hematopoeitic stem cell will develop int.

Plasma

Characteristics:
  • liquid part of blood (consists of water, nutrients, salts)
  • 90% water
  • plasma proteins: albumins--thicken and maintain blood volume, globulins--antibodies that protect body from infections, fibrgens & prothrombin--needed for coagulation


Functions & Maintaining Homeostasis:

  • rids rids cells of waste
  • hormones/regulatory chemicals dissolve into plasma


Plasma Donation:

  • plasma cannot be synthesized in a laboratory, creating a need for plasma
  • used to treat hemophilia, immune system deficiencies, and burn/shock victims
  • draw blood through a needle
  • plasma is separated from the rest of the blood by centrifusion

Erythrocytes (RBCs)

Characteristics:
  • usually live 120 days
  • production is caused by the need for oxygen
  • filled with hemoglobin
  • cells do not contain a nucleus
  • biconcave disk shape


Functions & Maintaining Homeostasis:

  • carry oxygen to cells
  • transport harmful carbon dioxide away from cells


Hematocrit Test (Hct):

  • measurement of the total blood volume composed of RBCs
  • blood is placed in a hematocrit tube, then spun to separate the plasma, white blood cells, platelets, and RBCs


Hemoglobin (Hb):

  • globular protein
  • four iron molecules attached to each Hb molecule
  • bands together with oxygen
  • carries large amounts of oxygen to different cells
  • Hb test: measures amount of Hb in blood; finger prick or drawn by needle to collect a sample of blood


Anemia:

  • definition: inadequate number of RBCs, defficiency of Hb, or lack of iron in the blood
  • hemolytic: RBCs are prematurely destroyed/killed
  • iron defficiency: without the proper amount of iron in the diet, Hb is not able to be produced
  • hemorrhagic: decrease in number of RBCs cause by excessive bleeding or ulcers
  • sickle cell: abnormal type of Hb; solid crystals form in RBCs, oxygen content is low causing deformation of the RBC
  • pernicious: a failure in the stomach lining that affects the absorption of the B12 vitamin, which is necessary for RBC production


Polycythemia:

  • the excess production of RBCs in bone marrow; chronic condition
  • causes: mutation in a protein belonging to a bone marrow cell
  • treatments: removing blood from the body, low-dose asprin, medications


Donating Blood:

  • a needle is used to draw the blood (about a pint is collected)
  • blood donations can be done as often as every eight weeks
  • the blood is separated into its different components (RBCs, WBCs, platelets)
  • could potentially help three different patients
  • shelf-life up to 42 days

Luekocytes (WBCs)

Characteristics:
  • larger than RBCs
  • contain a nucleus
  • phagocytosis: ability to egulf foreign material and digest it
  • chemotaxis: cells are drawn to an area by chemical release
  • diapedesis: movement of cells through vessels and tissues


Function:

  • Immune System: attack foreign and harmful viruses and bacteria


The Five Types:

Granulocytes: short lived; give color to cells

1) neutrophil

  • most common (60% of total)
  • segmented nucleus
  • fights acute bacterial infections
  • highly phagocytic

2) eosinohil

  • makes up 2% of total
  • larger than a neutrophil
  • bilobed nucleus
  • fights parasitic infections, breaks down antibody complex

3) basophil

  • rarest (0.0004% of total)
  • bilobed nucleus
  • involved in inflammation (Histamine, Bradykinin)
  • contains Heparin (anti-coagulant)

Agranulocytes: long lived; seen in chronic infections

4) lymphocyte

  • second most numorous (31% of total)
  • round nucleus, little cytoplasm
  • very long life and produces immunity
  • non-phagocytic, fight viruses

5) monocyte

  • also called marcrophages (if not in blood)
  • largest of all WBCs
  • kidney shaped nucleus
  • highly phagocytic
  • seen in chronic infections


Conditions & Treatments:

  • leukemia: cancer of red bone marrow and lymphatic system; can be treated by chemo, radiation, and targeted therapy and stem cell transplants.
  • mononucleosis: the "kissing disease;" can be passed spread by saliva and sneezing; treatment is bedrest and drinking fluids
  • leukopenia: low white blood cell count; causes a higher risk of infection; can be treated by blood transfusions, and medications.
  • multiple myeloma: cancer of plasma cells where they accumulate in bone marrow that crowd healthy blood cells; can be treated by chemo, targeted, radiation and biological therapies, corticosteroids, and stem cell transplants.

Thrombocytes (Platelets)

Characteristics:
  • sticky
  • flat


Function & Maintaining Homeostasis:

  • platelet plug
  • forms clots in blood using thrombin and fibrinogen creating fibrin
  • fibrin seals damaged blood vessels


Homeostasis:

  • the stoppage of blood

1) vascular spasm

2) platelet plug (temporary seal)

3) clotting cascade (coagulation)


Hemophilia:

  • rare condition
  • blood does not coagulate
  • high risk of internal bleeding
  • treatment: antifibrinolytics, fibrin sealants, and injection of desmopressen (hormone).


Blood Thinners:

  • coumadin (warfarin): helps to prevent new clots from forming and prevents clot from progressing
  • heparin: given to prevent clots in patients after surgery; can be used to treat certain heart and lung conditions
  • aspirin: used to reduce risk of heart attack