Cari’s Story

Blood is a connective tissue. Blood has three general functions transpotation of oxygen, carbondioxide, nutrients and hormones to and from the body; regulation, blood regulates pH(normal pH is 7. 35-7. 45) and body temperature; protection, blood is able to clot after an injury thus protecting execessive blood loss and white blood cells protect the body against disease. Components of blood are plasma which is the liquid part of blood and formed elements which are cell fragments including platelets.

There are two types of cells in blood, red blood cells (RBC’s) or erythrocytes and white blood cells (WBC’s) or leukocytes. Hematocrit is the percentage of total blood volume occupied by RBC’s. Hematocrit is measured in percentages. Normal ranges of hematocrit in females is between 38-46% and for males is 40-54%. Lower than normal hematocrit levels could indicate anemia, loss of red blood cells, malnutrition, leukemia, nutritional defeciencies such as lack of iron, vitamin B12 and B6.

Bacterial infection will lower the number of red blood cells due to increase of white blood cells thus lowering the hematocrit percentage. Lymphocytes are a type of white blood cells that help carry out cell mediated and antibody-mediated immune responses1. Lymphocytes have a longer lifespan than other formed elements of blood which are continually dying and replaced within hours, days or weeks. A person with Type B blood can receive Type O because Type O blood is a universal donor. Lymphocytes is a white blood cell that has a round nucleus surrounded by blue halo of cytoplasm with no visible granules.

They have B cells that differentiate into cells that produce antibodies, T cells that attack viruses, fungi, transplanted cells, cancers, some bacteria, allergic reactions, natural killer cells that attack wide variety of infectious microbes and certain spontaneously arising tumor cells. 2. Basophils are white blood cells that contain dense blue-purple granules that hide the nucleus. Basophils release heparin, histamine, and serotonin. They intensify inflammatory response, they are also involved in hypersensitivity (allergic) reactions.

2.Monocytes are white blood cells that have a u-shaped nucleus and a bluish, foamy cytoplasm with no visible granules. Monocytes develop into macrophages and phagocytize microbes. Monocytes also clean up cellular debris following an infection. 2. Neutrophils are white blood cells that contain small, pale lilac granules and a four-lobed nucleus. Neutrophils release lysozyme, strong oxidants, and defensins. Neutrophils also perform antibiotic activity against bacteria and fungi. 2. Eosinophils are white blood cells that contain re-orange granules and two-lobed nucleus.

Eosinophils combat the effects of histamine. They have inflammatory and allergic responses. Phagocytize in eosinophils have antigen-antibody complexes and combat some parasitic worms. 2. Leukocyte levels are high in a person who is infected with a parasitic diseases would mean that the leukocytes are attacking the parasitic disease thus need to increase eosinophils which attack parasitic worms. Leukocytes are responsible for the immune responses against pathogens. In regions where malaria is endemic some people build up immune resistance malaria pathogens.

Blood remains in its liquid form as long as it stays within the blood vessels. If the vessel breaks the blood thickens and forms into a gel. This gel is called a clot. Clotting can be divided into three stages. Stage one involves several reactions of the clotting sequence ending in formation of prothrombinase. In the second stage prothombinase converts prothombin (a plasma protein formed by the liver) into the enzyme thrombine. In the third stage thrombine converts soluble fibrogen (another plasma proyein formed by the liver) into soluble fibrin. Fibrin forms the threads of the clot.

1.Extrinsic pathway of blood clotting occurs rapidly within a matter of seconds if trauma is severe. Intrinsic pathway of blood clotting is more complex and it occurs slowly usually requiring several minutes. Intrinsic is within the blood and outside tissue damage is not needed. References Jenkins, G. , Kennits, c. , and Tortora, G. (2007). Anatomy and Physiology (2nd ed. ). Hoboken, NJ: John Wiley & Sons, Inc. Notes from Dr Bruce Anderson, GE 259, Chapter XVIII Blood, fall semester 2012. Blood Rufence Mwamburi Itt-Tech Earth City Anatomy and Physiology 2 Dr. Bruce Anderson March 23,2010