Lecture -1 Dr. Zahoor Ali Shaikh 1

BLOOD We will discuss i). Compositions and Functions of Blood, Plasma ii). Hematocrit iii). Plasma Protein 2

BLOOD  What is Blood ? It is transport medium in the body. It transports O 2 and substances absorbed from GIT [Gastro Intestinal Tract] to the tissues and returns CO 2 to lungs and products of metabolism to the kidneys. 3

BLOOD  Functions of Blood 1. Carries O 2 to the tissues and transports CO 2 from the tissues to the lungs. 2. Transport of materials between the cells. 3. Buffers changes in pH. 4. Helps in regulation of body temperature. 5. Plays major role in body defense system. 6. Minimizes blood loss, when blood vessel is damaged [blood clotting]. 4

BLOOD  What is composition of Blood ? It has 1. Plasma – 55% 2. Cells - 45% Cells are -Erythrocytes [RBC - Red Blood Cells] -Leukocytes [WBC – White Blood Cells] -Platelets 5

BLOOD [CELLS] cont. RBCs have membrane and contain hemoglobin that transport O 2 in the blood. WBCs work for defense of body, and have immune system. Platelets play important role in blood clotting [Hemostasis]. 6

BLOOD  What is Hematocrit or Packed Cell Volume [PCV]? It is ratio of cells [RBC, WBC, Platelet] to the plasma. PCV - 45% [40 to 47%] Plasma - 55%. 7

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BLOOD Important Information 1. Blood represents about 8% of body weight. 2. Average volume of blood In women – 5 liters In men – 5.5 liters 3. pH of Blood – 7.4 [slightly alkaline] 4. Blood specific gravity Blood viscosity is two and half times that of water. 9

TEST YOUR KNOWLEDGE Q1. What is the Blood volume of New born baby? Answer: About 280 ml. 10

PLASMA We will discuss PLASMA:  What is PLASMA ? It is fluid portion of blood, straw colored. Composition of Plasma: - water – 90% - inorganic constituents – 1% E.g. Electrolytes – Na +, Cl -, K +, HCO 3 -,Ca 2+ They play role in membrane excitability. 11

COMPOSITION OF PLASMA [cont.] Organic constituents - Plasma protein – 6 – 8% - Other organic substances present e.g. Glucose, amino acids, lipids and vitamins. Waste products – urea, creatinine, bilirubin. Dissolved gases – O 2 and CO 2 Hormones 12

SERUM  WHAT IS SERUM ? Serum has same composition as Plasma except that its fibrinogen and other clotting factors have been removed. Plasma clots on the standing but serum does not clot. 13

PLASMA PROTEIN  Plasma Protein are 1. Albumin 3.5 – 5 g/dl 2. Globulin 2.5 g/dl 3. Fibrinogen 0.3 g/dl Plasma Protein can not pass through capillary pores, therefore, they have colloid osmotic pressure [Oncotic pressure] of 25 mmHg which holds the water inside and maintains plasma volume. 14

PLASMA PROTEIN FUNCTIONS Specific function of each protein: 1. Albumin 3.5 – 5 g/dl, most abundant - molecular weight half life 20 days - synthesized in liver - Plasma osmotic pressure is mainly due to albumin (80-90%). 15

PLASMA PROTEIN FUNCTIONS 1. Albumin [cont] - Albumin binds to many substances e.g. bilirubin, bile salts, penicillin for transport in the plasma. 16

PLASMA PROTEIN FUNCTIONS 2. Globulins – molecular weight 156, subclasses (i). Alpha [ α] (ii). Beta [β] (iii) Gamma [γ] Function of Alpha & Beta Globulins They carry substances like thyroid hormones, cholesterol, iron, lipids, insulin, vitamins A, D, K. Many blood clotting factors are alpha or beta globulin. Angiotensinogin is alpha globulin. 17

PLASMA PROTEIN FUNCTIONS Gamma Globulin – Immunoglobulin [Ig] Gamma Globulins are antibodies and play important role in body defense mechanism. Immunoglobulin [Ig] are - IgG – work for defense of body - IgM – work for defense of body - IgA – present in secretion e.g. saliva, breast milk, intestinal secretion - IgD – recognize antigen - IgE – play role in allergic reaction 18

PLASMA PROTEIN 3. Fibrinogen - molecular weight 400,000 - Fibrinogen play key factor in blood clotting. Important Note - Plasma protein – Albumin, Fibrinogen, Alpha, and Beta Globulin are synthesized in liver, but gamma globulin are produced by plasma cell and B- lymphocytes. 19

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APPLIED Hypoproteinemia Causes - less protein intake - protein loss in kidney - liver disease, decrease synthesis of protein - intestinal disease, less absorption of protein - in hypoproteinemia, there is decreased plasma osmotic pressure, therefore, there is Edema [collection of fluid in subcutaneous tissue]. 21

WHAT YOU SHOULD KNOW FROM THIS LECTURE ? Composition & Functions of Blood What is Hematocrit or PCV ? Composition & Functions of Plasma Difference between Blood, Plasma, and Serum Normal Blood Volume, Plasma Volume, Plasma Osmotic Pressure Plasma Protein & their Functions Hypoproteinemia and its causes, Edema 22

THANK YOU 23