Blood and Blood elements PDF

Asst. Prof. Dr. Lubna Al-Gailani MD., PhD. Cyprus International University Faculty of Medicine 2024-2025 Circulatory system 1. Blood 2. Blood vessels 3. Heart Distribution of Blood in the Body  Physical properties of blood Amount : 7-8...

Asst. Prof. Dr. Lubna Al-Gailani MD., PhD. Cyprus International University Faculty of Medicine 2024-2025 Circulatory system 1. Blood 2. Blood vessels 3. Heart Distribution of Blood in the Body  Physical properties of blood Amount : 7-8% of bw ♂ 5-6L ♀ 4-5L – Adult 70 ml/kg, less in women and obese?  Viscosity: 3x water – Resistance to flow is higher than water – What makes the blood more viscous? – Plasma proteins, RBCs, water  pH: 7.35 – 7.45 (slightly alkaline) Color: bright red (oxygenated blood) dark red (deoxygenated blood) Temperature: ~ 38 oC – Is it different from body temperature?  Hematocrit (Ht, HTC) Packed cell volume (PCV) Erythrocyte volume fraction (EVF) Volume percentage (%) of the blood cells The rest is plasma 10000 rpm Man 42%, woman 38% 5 min Can be calculated by multiplying MCV and RBC number  Serum-plasma Plasma, if coagulation is prevented and the blood is centrifuged, the fluid on top of the cells is plasma Straw-yellow color due to bilirubin Serum, the fluid part after coagulation It is like plasma without coagulation factors Contains no fibrinogen  Erythrocyte sedimentation rate (ESR) A measure of how fast RBCs sediment in a tube Westergren tube is traditionally used Automatically performed in automated analyzers 0-15 mm/h Faster in woman, obese and elderly Related to blood protein levels, especially fibrinogen   physiologically in pregnancy and menstruation   in inflammation, rheumatoid arthritis, cancer   polycythemia, sickle cell anemia, hereditary spherocytosis Important in prognosis of the diseases rather than diagnosis  Functions of the blood Transportation – Respiration, O , CO 2 2 – Nutrition, aa, glucose, fa – Endocrine, hormons Regulation of body temperature Osmotic regulation pH regulation Coagulation Immunity  Transportation function 97% of O2 is carried with Hb in RBC – 3% is dissolved in plasma 23% of CO2 is carried with Hb – 7% is dissolved in plasma – 70% as HCO3- in plasma Nutrients absorbed from the guts or released from the liver are transported in blood Metabolic waste products released in tissues are carried to the kidney Hormons are carried to their target cells in blood  Regulation of body temperature Blood absorbs the heat generated in skeletal muscles and distribute to other tissues At high body temperatures blood flow to the skin increases At low body temperature blood flow is directed to the vital organs rather than the skin and the extremities  Osmotic regulation Osmolarity of ECF affects cellular osmolarity and hence volume and functions Blood osmolarity is determined by blood proteins and electrolytes ~280 mosm/L Isotonic-hypotonic-hypertonic Isoosmolar-hypoosmolar-hyperosmolar 0.9% NaCl, 5% glucose  Acid–base regulation Venous blood; 7.36, arterial blood; 7.40 pH is important for the functioning of enzymes and proteins Buffering systems in blood, kidney and lungs help regulate blood pH Bicarbonate buffering system  Coagulation Platelets form a plug at the site of injury (primary hemostasis) Coagulation factors cause formation of fibrin strands, which strengthen the platelet plug (secondary hemostasis)  Immune function of the blood Blood contains cells and their products figthing against foreign substances and cells Neutrophil Eosinophil Basophil Monocyte Lymphocyte Blood composition Blood Plasma Blood cells (55%) (45%) 1. Water 1. RBCs 2. Plasma proteins 2. Leukocytes 3. Other dissolved 3. Platelets substances  Plasma 92% water 1% inorganic substances mM Na 7% organic substances 142 – plasma proteins, lipids, sugars, urea, K ammonia 4 Gases Ca 2.4 Mg 1.2 Cl 103 HCO 28  Blood Sugar  Glucose (source of energy) Lipids  Neutral fats, cholesterol, and phospholipids  Supply energy or stored as fat Inorganic salts  Ca2+ ions and the Na2+ ions  Salt ions (chlorides, bicarbonates, phosphates, sulfates)  Electrolytes ( Na2+, Ca2+ , K+ and Mg2+ )  Iodides and iron Special Plasma Substances Gases Hormones Oxygen Enzymes Carbon dioxide Clotting elements Nitrogen Antibodies Non-protein nitrogen of the plasma Urea Uric acid Creatinine Refers to nitrogen-containing substances other than proteins and AA ↑ in deranged kidney function  plasma proteins Total 7,3 g/dL (6-8 g/dL) – Albumin 60% (4.5 g/dL) Major protein creating oncotic pressure Binds water, ions, fatty acids, hormons, bilirubin, drugs – Globulin 35% (2.5 g/dL) Alpha, beta, gamma globulins Some are carriers (iron, copper, lipids, Hb) Immunoglobulins (IgM, IgG) – Fibrinogen 4% (0.3 g/dL) Forms clot after converted into fibrin by thrombin – Other proteins 50 Triglycerides = 130 mg/dL fasting – >180 mg/dL post-meal Hyper-, hypoglycemia Blood composition Blood Plasma Blood cells (55%) (45%) 1. Water 1. RBCs 2. Plasma proteins 2. Leukocytes 3. Other dissolved 3. Platelets substances  Red Blood Cells 45% of the blood (hematocrit) 99% of blood cells’ volume Has no organel Has glycolytic enzymes Biconcave disc – higher surface area/volume ratio – O2 enrtry/exit 2 μm thick, 7.5 μm diameter Membrane elasticity allows passage through narrow capillaries Average lifespan 120 d  Red Blood Cells 3 milion RBCs enter circulation every second 1% produced/day, 1% destroyed/day Produced in bone marrow of sternum, pelvis, vertebrae, ribs in adults Destroyed by MPS (mononuclear phagocyte system) cells Iron is recycled, heme is converted into bilirubin and excreted Main functions: Transport of O2, CO2 Acid-base buffer  Red Blood Cells Number, Man, 5.4 milion/μl Woman, 4.8 milion/μl Polycythemia (primary, secondary, physiological) Anemia Size, Mean cell diameter (MCD), 7.5 μm Mean corpuscular volume (MCV), 80-100 fl MCV = hematocrit/RBCs in 100 ml blood Normocytic, macrocytic, microcytic  Red Blood Cells Shape Normally biconcave disc Spherocyte, sickle cell Hb concentration Mean corpuscular hemoglobin (MCH) 26-32 pg MCH = Hb (g/dL)/RBCs in 100 ml blood MCHC (mean corpuscular Hb cocentration), 32-36 g/dL MCHC = Hb g/dL / hematocrit Normochromic, hypochromic, hyperchromic  Reticulocytes Young RBCs Little amount of RNA Slightly larger than mature RBCs RNA is removed during passage through spleen A sign of RBC production 0.2-2% of RBCs is normal 7% in newborns