Blood

• Blood - transports everything that must be carried from one place to another, such as:

  • Nutrients
  • Wastes
  • Hormones
  • Body heat
• Oxygen rich - blood is scarlet red
• Oxygen poor - blood is dull red or purple
• Erythrocytes (Red Blood Cells or RBCs) - Main function is to carry oxygen
• Hemoglobin - iron-bearing protein that gives color red in the blood
• Leukocytes (White Blood Cells or WBCs) - Crucial in body’s defense against disease
• Anemia - Lower-than-normal number of RBCs
• Polycythemia - excessive or abnormal increase of RBCs
• Leukocytosis - increased number of white blood cells in the blood.
• Leukopenia - low white blood cell count, commonly caused by certain drugs,
• Leukemia - immature WBC are produced and bonemarrow becomes cancerous
• Granulocytes

  • Granules in their cytoplasm can be stained
  • Possess lobed nuclei
  • Include neutrophils, eosinophils, and basophils
• Agranulocytes

  • Lack visible cytoplasmic granules
  • Nuclei are spherical, oval, or kidney-shaped
  • Include lymphocytes and monocytes
• Neutrophils - part of granulocytes that is most numerous WBC, function as phagocytes at active sites of infection.
• Eosnophils - type of granulocytes that nucleus stains blue-red, function is to kill parasitic worms and play a role in allergy attacks
• Basophils - type of granulocytes that is rarest of the WBCs
• Lymphocytes - type of agranulocytes that is lightly larger than RBCs, play a role in immune response
• Monocytes

  • Largest of the white blood cells,
  • Distinctive U- or kidney-shaped nucleus
  • Function as macrophages when they migrate into tissues
  • Important in fighting chronic infection
• Platelets

  • Fragments of megakaryocytes (multinucleate cells)
  • Needed for the clotting process
  • Normal platelet count is 300,000 platelets per mm3 of blood
• Hemostasis - process of stopping the bleeding that results from a break in a blood vessel
• Antigens - Blood contains genetically determined proteins
• Antibodies - are the “recognizers” that bind foreign antigens and help protect the body from pathogens
• Thrombus - A clot in an unbroken blood vessel
• Embolus - breaks away and floats freely in the bloodstream
• Thrombocytopenia - Insufficient number of circulating platelets / low platelets count
• Hemophilia - Hereditary bleeding disorder / Normal clotting factors are missing
• Hematopoiesis - the process of producing blood cells in the bone marrow
• Components of Blood

  • Red Blood Cells
  • White Blood Cells
  • Platelets
  • Plasma
• Erythropoietin - Rate of RBC production is controlled by a hormone
• Thrombopoietin - stimulates production of platelets from megakaryocytes
• Sickle cell anemia (SCA) - results from abnormally shaped hemoglobin
• 5-6 - number of blood found in a healthy adult in Liters.
• Blood pH is slightly alkaline, between 7.35 and 7.45
• Blood makes up 8 percent of body weight
• Plasma proteins - Most abundant solutes in plasma
• Albumin - an important blood buffer and contributes to osmotic pressure
• Clotting proteins - help to stem blood loss when a blood vessel is injured