THE BLOODPLASMA Lecture -1 Dr. Zahoor Ali Shaikh
BLOOD • We will discuss i). Compositions and Functions of Blood, Plasma ii). Hematocrit iii). Plasma Protein
BLOOD • What is Blood ? • It is transport medium in the body. It transports O2 and substances absorbed from GIT [Gastro Intestinal Tract] to the tissues and returns CO2 to lungs and products of metabolism to the kidneys.
BLOOD • Functions of Blood • Carries O2 to the tissues and transports CO2 from the tissues to the lungs. • Transport of materials between the cells. • Buffers changes in pH. • Helps in regulation of body temperature. • Plays major role in body defense system. • Minimizes blood loss, when blood vessel is damaged [blood clotting].
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
BLOOD [CELLS] cont. • RBCs have membrane and contain hemoglobin that transport O2 in the blood. • WBCs work for defense of body, and have immune system. • Platelets play important role in blood clotting [Hemostasis].
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%.
BLOOD • Important Information • Blood represents about 8% of body weight. • Average volume of blood In women – 5 liters In men – 5.5 liters • pH of Blood – 7.4 [slightly alkaline] • Blood specific gravity 1.055 • Blood viscosity is two and half times that of water.
TEST YOUR KNOWLEDGEQ1. What is the Blood volume of New born baby? Answer: About 280 ml.
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+, HCO3-,Ca2+ They play role in membrane excitability.
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 – O2 and CO2 • Hormones
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.
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.
PLASMA PROTEIN FUNCTIONS • Specific function of each protein: • Albumin 3.5 – 5 g/dl, most abundant - molecular weight 69000 - half life 20 days - synthesized in liver - Plasma osmotic pressure is mainly due to albumin (80-90%).
PLASMA PROTEIN FUNCTIONS • Albumin [cont] - Albumin binds to many substances e.g. bilirubin, bile salts, penicillin for transport in the plasma.
PLASMA PROTEIN FUNCTIONS 2. Globulins – molecular weight 156,000 - 3 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.
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
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.
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].
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