BLOOD - COMPOSITION AND FUNCTIONS

Blood •Blood is a connective tissue in fluid form •considered as “Fluid of life” Because it carries oxygen from lungs to all parts of the body & carbon-di-oxide vice versa•Known as “Fluid of growth” because it carries nutritive substances from the digestive system

•Blood is also called “FLUID OF HEALTH” because it protects the body against the diseases.

Physical properties of blood

• Color - red• Volume - Avg. 5L• pH – 7.4 (slightly alkaline)• Specific gravity- 1.052-1.061

Blood compositonsLiquid Solid (formed element )

Composition of Plasma Solids - Organic substances & Inorganic Substances• Organic substances - 1.Plasma proteins 2.Amino acids 3.Carbohydrates 4.Fats 5.Hormones & Enzymes 6.Antibodies• Inorganic substances- Sodium , calcium ,

potassium , Iron , phosphate etc

Plasma proteinsProteins found in blood plasma•Plasma proteins are :Serum albumin

Serum globulin Fibrinogen

Properties of plasma proteins

• Total porteins-7.3g/dl

• Serum albumin-4.5g/dl

• Serum globulin-2.3g/dl

• Fibrinogen-0.3g/dl

Molecular weight • Albumin-69,000• Globin-15,6,000• Fibrinogen-

4,00,000

Origin of Plasma Proteins

In embryonic stage the plasma proteins are synthesized by the mesenchymous cells The albumin is synthesized first and then other proteins are synthesized later

In adults the plasma proteins are synthesized mainly from reticulo-endothelial cells of liver The plasma proteins are synthesized also from spleen , bone marrow , disintegrating blood cells and general tissues cells Gamma globulin is synthesized from B lymphocytes

Origin of plasma protiens

Functions of plasma proteins Role in coagulation of blood

Role in defense mechanism of body

Role in transport mechanism

role in maintenance of osmotic pressure in the blood

Role in regulation of acid base balance

Role in viscosity of blood

Role in erythrocyte sedimentation rate (ESR)

Role in suspension stability of red blood cells

Formed elements• Blood contains blood cells which are

called formed elements• Three types of cells are present in the

blood Red blood cells or erythrocytes White blood cells or leukocytes Platelets or thrombocytes

Red blood cells Red blood cells are the non-nucleated formed element in the blood Red blood cells are also known as erythrocytes Red color of the red blood cells is due to the presence of the coloring pigment called hemoglobinRBC are larger in no as compared to other blood cells

Normal value RBC count ranges between 4 and 5.5 million/cu mm of blood Adult male – 5 million/cu mmAdult female – 4.5 million/cu mm

Morphology of red blood cells Shape and diameter of RBC

Shape – Disc shaped & biconcave.Central position is thinner & periphery is thicker

Diameter – 7.2U

Thickness – At the periphery it is thicker. The difference is because of biconcave shape

Surface area - 120 sq.

Volume – 85 to 90 Cu. U

eRouleaux formation When the blood is taken outof the blood vessels , the RBCs pile up one above another like the pile of coinsThis property of RBC is called rouleaux formation

life span of RBC Average life span of RBC is about 120 days

After the lifetime the old RBCs are destroyed in Reticulo-endothelial system

Increase = pOlycythemia Decrease= Anemia

Variation in RBC count

Introduction of anemia • Anemia is a reduction in the number of RBCs, the

quantity of hemoglobin, or the volume of RBCs• Because the main function of RBCs is oxygenation,

anemia results in varying degrees of hypoxia

Anemia•Classification of anemia

Morphological classification Etiological classification

Anemia Morphological anemia 1 . Normocyrtic normochromic anemiaSize and colour of RBC are normal but number are

less

2. Macrocytic normochromic anemiaRBC are larger in size with normal colour . Rbc count

is less

Anemia3. Macrocytic hypochromic anemia RBC are larger in size MCHC is less ,so the cells are

pale

4 . Microcytic hypochromic anemia RBC are smaller in size with less colour

Anemia • Etiological classification Study of cause or origin they are divided

into five types 1. Hemorrahagic anemia 2. Hemolytic anemia3. Nutrition deficiency anemia4. Aplastic anemia 5. Anemia of chonic disesses

SYMPTOMSANEMIA

EYESYELLOWING

SKINpaleness, coldness, yellowing

Anemia - symptoms• Muscular- weakness• Intestinal – changed stool color • Central – fatigue , dizziness , fainting • Blood vessels – low blood pressure • Heart- palpitations , rapid heart rate ,

chest pain , angina , heart attack • Spleen – enlargement

ReferencesEssentials of Medical Physiology- K SembulingamWikipedia.orgGuyton & Hall Textbook of PhysiologyTextbook of Physiology- A.K.JainGanong’s review of Medical Physiology

Presented by- Almas Naqvi Vaishali Pandya