Blood Course

2 Blood Physiology Lecture 1 Composition of Blood, Plasma and Plasma Proteins 2 nd year Physiotherapy 2nd year Physiotherapy- November 2008

3 Lecture 1 Objectives: By the end of this lecture the student should be able to: 1.Describe the composition of blood. 2.State normal values of blood and plasma volume. 3.State the sites of blood cell formation at different ages. 4.Define hematocrit and state its normal value. 5.Describe the functions of blood as a tissue. 6.Describe the composition of plasma. 7.List types of plasma proteins. 8.State the normal plasma protein concentration. 9.Describe the functions of plasma proteins. 10.Outline the different causes of low plasma protein concentration. 2nd year Physiotherapy- November 2008

4 Blood Blood is the only liquid tissue. It represents about 8% of total body weight. Average blood volume is 5 L in women and 5.5 L in men. Blood is composed of cellular elements suspended in liquid plasma. Average plasma volume is 3 L. 99% of cellular elements are RBCs. 2nd year Physiotherapy- November 2008

5 Composition of the blood 1-Plasma: fluid part, 55% of total blood volume, mainly water, organic and inorganic substances. 2-Cellular elements: 45% of total blood volume. RBC or erythrocytes (5x10 6 /mm 3 ) WBC or leukocytes (3-10x10 3 /mm 3 ) Platelets or thrombocytes ( x10 3 /mm 3 ) 2nd year Physiotherapy- November 2008

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7 Haemopoeiesis & Sites of blood cell formation Haemopoiesis: Process of blood cell production. Sites: Fetal life: Liver, spleen and bone marrow. After birth: Bone marrow After the age of 20: membranous bone marrow (vertebrae, sternum, ribs and ilia, upper ends of humerus and femur).

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Haematocrit or packed cell volume Definition: % of total blood volume occupied by RBCs. 10 Normal value: Adult male: 47 % Adult females: 42 % 2nd year Physiotherapy- November 2008

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2nd year Physiotherapy- November Minute Quiz A patient was found to have a haematocrit of 30%. Name 2 possible causes.

13 Functions of Blood 1-Transport function: O 2 and nutrients to cells CO 2 and metabolic waste products away from cells Hormones, drugs, etc… 2-Defensive function: WBC and antibodies 3-Haemostatic function: * Stop bleeding (platelets and clotting factors 4-Homeostatic function: –pH –Temperature –Plasma volume 2nd year Physiotherapy- November 2008

14 Plasma Composition Water: 90% Solids: 10% 1-Organic substances 9.1%: »Plasma proteins 6-8% of plasma’s total weight »Nutrients (a.a., glucose, lipids, vitamins) »Waste products (creatinine, bilirubin, urea) »Dissolved gases (O 2 and CO 2 ) »hormones 2-Inorganic substances: 0.9% (Na, Cl, others) 2nd year Physiotherapy- November 2008

Plasma proteins Normal concentration g/dl Plasma proteins are: 1-Albumins (3.5-5 g/dl) 2-Globulins α1, α 2, β1, β 2, γ 3-Fibrinogen Most of the plasma proteins are synthesized in the liver. Circulating antibodies (γ globulins) are synthesized by plasma cells (activated B-lymphocytes). 152nd year Physiotherapy- November 2008

Functions of Plasma proteins 1-Osmotic function: plasma proteins (mostly albumin) exert an osmotic pressure across the capillary wall (colloid osmotic pressure or oncotic pressure). Plasma volume regulation 162nd year Physiotherapy- November 2008

172nd year Physiotherapy- November 2008

18 2-Buffer action: plasma proteins act as acids (due to help in keeping pH of blood constant. COOH) and act as alkali (due to NH 2 group). 3-Defensive function:  -globulins defend the body against microorganisms and their toxins. 4- Blood clotting: Plasma protein & fibrinogen are essential for blood clotting. 2nd year Physiotherapy- November 2008

5-Contributes to blood viscosity: blood viscosity prevents the rapid flow of blood from arterial to venous system. 6-Transport: carrier proteins for small molecules such as vitamins, hormones, trace elements & drugs. 7-Nutritive: used by the tissue during prolonged starvation. 192nd year Physiotherapy- November 2008

20 Hypoproteinema: low plasma protein concentration. –Causes: »Liver diseases »Renal diseases »Prolonged starvation »Congenital deficiency (e.g. afibrinogenemia 2nd year Physiotherapy- November 2008

21 Finally… Write down the muddiest point. (What you do understand) Try to summarize the lecture in your own words. 21

Summary What is the composition of the blood? What is the normal blood volume, plasma volume? What is haematocrit value? Normal value? What are the general functions of blood? What is the composition of plasma? Describe plasma proteins in terms of their: Types Normal concentration Sites of formation Functions What are the causes of Hypoproteinema? 22