Functions of Blood
* Transport of gases, nutrients, and waste products.
* Transport of processed molecules. (Vitamin D, Lactic Acid) * Transport of regulatory hormones.
* Regulation of pH and Osmosis.
* Maintenance of Body Temp.
* Protection against foreign substances.
* Clot Formation.
Blood is a connective tissue that consists of a liquid matrix containing cell and cell fragments. * Plasma – Liquid Matrix
* Formed Elements – cell
Plasma is a pale yellow fluid that consist of:
* 91% Water
* 7% Protein
* 2% Others (Ions,nutrients)
Plasma contains dissolved proteins.
* Albumin – makes of 58% of the plasma protein. Important contribution in Osmotic Pressure. * Globulin – 38%. These are antibodies; has clotting factors. * Fibrinogen – 4%. Activation of clotting factors converts fibrinogen to fibrin, a threadlike protein that forms blood clots. Serum is plasma w/o clotting factors.
* Red blood cells or erythrocytes constitute 95% of the total formed elements. * White blood cells or leukocytes and
* Platelets or thrombocytes constitute for the remaining 5%.
Hematopoiesis is the process of blood cell production and is confined primarily to red bone marrow, and lymphatic tissues. Stem Cells or hemocytoblasts is where all the formed elements are derived from. Growth factors determine the types of formed elements derived from the stem cells. Red Blood Cells
* Edges are thicker than the center of the cell
* Can bend or fold
* Gases moves in and out easily.
* Loses their nuclei to be mature.
* Lives for 120 days +/ -
Hemoglobin is the main component of a red blood cell. This accounts for 1/3 of the total volume and is responsible for the red color. Oxygen transport is accomplished by hemoglobin. 98.5% of the oxygen transport. Hemoglobin that is
* Bound by oxygen is bright red
* Not bound by oxygen is a darker red.
Stem cells > proerythroblasts > red blood cell line.
Red blood cells are the product of series of cell division.
Each division, each cell changes and becomes more mature.
Low blood o2 levels stimulate red blood cell production by increasing the formation and release of the glycoprotein erythropoietin. Erythropoietin stimulates red bone marrow to produce RBC.
White blood cells
* Spherical cell that lack hemoglobin
* Larger than RBCs
* Has a nucleus
* Travel through ameboid movement.
Function of WBC
* Protection for microorganism
* Remove dead cells
Each white cell is named according to its appearance in stained preparations. * Granulocytes contain large cytoplasmic granules.
* Agranulocytes can’t be easily seen granules.
Kinds of Granulocytes
* Neutrophils – the most common wbc. Phagocytocize microorganisms and other substances. * Basophils – least common. Blue / purple w/ basic dyes. Releases histamine and heparin. * Eosinophils – stains bright red. Has inflammatory responses caused by allergies and asthma. Kinds of Agranulocytes
* Lymphocytes – smallest. Prices antibodies, reject grafts, control tumor, regulate the immune sistm * Monocytes – largest. Forms macrophanges which phagocytize bacteria, dead cells, cell fragments and other debris. Platelets
* Minute fragments of cells
* Produced red bone marrow
* Fragments of megakaryocytes which plays an important role in preventing blood loss Preventing blood loss
* The body can tolerate a small amount of blood loss and can produce new blood to replace it. * But a large amount of blood loss can lead to death.
Loss of blood in minimized in 3 ways:
* Vascular Spasm – immediate but temporary constriction of the blood vessels. * Platelet Plug Formation – accumulation of platelets that can seal up a small break in a blood vessel. (Steps in the book) * Blood Clotting – When a blood vessel is damaged, blood clotting occurs. A...