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Blood. Blood. the average human has 5 litres of blood it is a transporting fluid it carries vital substances to all parts of the body. I. Function. A. Transport. nutrients. oxygen/carbon dioxide. waste. B. Maintaining Homeostasis . hormones. C. Protection.
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Blood • the average human has 5 litres of blood • it is a transporting fluid • it carries vital substances to all parts of the body
I. Function A. Transport • nutrients • oxygen/carbon dioxide • waste B. Maintaining Homeostasis • hormones C. Protection • immune system
II. Composition of blood • A. Plasma • Formed elements: Cells
Plasma liquid part of blood plasma transports:- • soluble food molecules • waste products • hormones • antibodies
91% water • 9% suspended material Proteins: Albumin – most abundant ->water regulation Globulins – transport steroid hormones Fibrinogen – formation of clots B. Formed elements Derived from hemocytoblast stem cells 1. Erythrocytes (RBC) • transports gases • 1/3 volume hemoglobin
Red blood cells specialisations 1) biconcave shape 2) no nucleus extra space inside 3) contain haemoglobin the oxygen carrying molecule 250million molecules / cell increases the surface area so more oxygen can be carried
Production: Erythropoietin from Kidney, (liver)---- Red bone marrow Iron required • RBC cycle 120 days Damaged RBC – liver and spleen Macrophages • Hemoglobin breakdown Heme (iron) globin (protein)
White blood cells • the bodies “defence” • part of the immune system • much larger than RBCs • far fewer • have a nucleus • 4000-1000 per mm3
2. Leukocytes (WBC) no hemoglobin has nucleus immune response hormones: interleukins and colony-stimulating (CSF)
Leukocytes: • Granulocytes: neutrophil, eosenophil, basophil • Agranulocytes: monocytes, lymphocytes
a. Neutrophils • granulocyte, the nuclei has 2-6 lobes • most numerous 60-70 %,increase in bacterial infection • phagocytic cells (lysosomes) b. Eosinophils • granulocyte • 1-3% • control inflammatory & allergic response c. Basophils • granulocyte, 0,5-1 % • least common • histamine (inflammatory) / heparin (prevents clots)
d. Monocytes • agranulocyte , 3-8% • largest WBC • after 3 days -> macrophages • phagocytes with lysosomes • ingests larger objects than Neutrophils
Lymphocytes Provide a specific immune response to infectious diseases. 20-25% There are 2 types: - - T-cells - B-cells They produce antibodies.
3. Platelets (Thrombocytes) : 150,000 to 400,000 per mm3 • fragments of megakaryocytes • blood clotting
Human blood groups A. ABO blood type 1. Antigens (proteins) on RBC 2. Antibodies against other antigens
B. Rh blood type 1. Antigens on RBC • Rh positive – has antigens • Rh negative – no antigens 2. Antibodies against Rh • Rh negative individual – antibodies after Rh+ encounter 3. Pregnancy • Rh neg w/Rh+ fetus • blood from fetus -> into mother’s blood • 2nd pregnancy w/Rh+ fetus -> antibodies attack