Homeostasis and Blood

By Maddie Walsh

Blood Characteristics

  • 55% plasma
  • 45% red blood cells
  • 1% white blood cells
  • 1% platelets
  • 12 pints for men/ 9 pints of women
  • red bone marrow actively produces blood cells and erythropoietin controls the production. It is a hormone that is produced by the kidney.


  • the liquid form of blood
  • a protein- salt solution where the red and white blood cells and platelets
  • 92% water
  • plasma suspends red, white blood cells, and platelets
  • it keeps the cell contact in and the foreign material out
  • plasma is used for research and that is why you get paid for plasma donations
  • how it is donated?
  1. Complete a Donor History Questionnaire.
  2. you will be taken to the donation area and seated in a comfortable seating bed.
  3. prepare your arm with antiseptic, insert the needle and begin the donation process.
  4. Blood will be drawn, plasma will be separated from your blood and red blood cells will be returned to your body through a process called plasmapheresis.
  • plasmapheresis is where the plasma and blood is separated and then the blood is put back into your body

Erythrocytes (Red Blood Cells)

  • small, red, biconcave
  • red blood cells have hemoglobin that carry oxygen from the lungs to other parts of the body
  • determining how much red blood cells there are in your body (percentage)
  1. Pricking your finger
  2. Getting the blood sample
  3. Putting it in a tube
  4. Spinning the tube to separate the red, white blood cells, and plasma
  • Hemoglobin- protein in blood to help carry oxygen
  • Hemoglobin Test- how much hemoglobin is in your blood
  • Anemia- where there isn't enough healthy red blood cells in the body
  1. Iron deficiency- too little iron in the body -> Iron injection
  2. Hemolytic- red blood cells are destroyed -> removal of spleen
  3. Hemorrhagic- reduced oxygen to organs -> cell transplant
  4. Sickle Cell- breaking down of blood cells -> Folic Acid
  5. Pernicious- decrease in blood cells with little vitamin B-12 -> blood transfusion

  • Polycythemia- red blood cell percentage increases caused by tumors and can be treated by nothing.
  • Blood Donating-
  1. cleanse area on arm
  2. insert a needle in vein
  3. takes pint of blood from body
  4. can last 8-10 minutes
  • every 8 weeks
  • blood lasts 120 days

Leukocytes (White Blood Cells)

  • cells of the immune system
  • protects the body against infection and foreign invaders
  • Five types of WBC
  1. neutrophils- defend against bacterial infection
  2. basophils- allergic response
  3. eosinophils- parasite infection
  4. lymphocytes- in lymphatic system
  5. monocytes- vacuum cleaner
  6. macrophages- eats foreign material
  • Conditions
  1. Leukopenia- decreased number of white blood cells
  2. Leukemia- cancer of blood forming tissues
  3. Mononucleosis- kissing disease, fatigue
  4. Multiple Myeloma- cancer of plasma cells

Thrombocytes (Platelets)

  • small, no nucleus
  • prevent bleeding
  • the endocrine system keeps keep internal balance by releasing hormones and the hormone is controlled by negative feedback.
  • Hemophilia- blood doesn't clot normally -> IV fluids
  • Blood Thinners-
  1. Warfarin- helps to prevent new blood clots from forming
  2. Heparin- prevents clots after/ during surgery
  3. Asprin- treats pain