Haematology I Whole Blood PDF

Haematology I Whole Blood Prof TT Nyakudya © Department of Physiology – 2023 1  Learning outcomes & assessment criteria Understand the general characteristics and functions of blood Assessment criteria Describe the composition and volume of who...

Haematology I Whole Blood Prof TT Nyakudya © Department of Physiology – 2023 1  Learning outcomes & assessment criteria Understand the general characteristics and functions of blood Assessment criteria Describe the composition and volume of whole blood Explain the general functions of blood Define ‘haematocrit’ and ‘erythrocyte sedimentation rate (ESR)’ Explain physiological and pathological causes for changes in haematocrit and ESR Explain the inorganic as well as the organic composition of plasma as well as the functions of the components 2  Components and Functions of Blood  Blood – The only specialized fluid connective tissue – Contains cells (formed elements) suspended in a fluid matrix (plasma)  Functions of blood – dissolved gases, nutrients, hormones & metabolic wastes – Regulating pH & electrolytes – Reduce fluid losses at injury sites – Immunity – Thgermoregulation 3 © 2018 Pearson Education, Ltd. 3 Characteristics of blood Physicochemical characteristics Color variations Blood pH Blood temperature Contribution to body weight 4  Components of blood  Whole blood – Plasma Fluid  Formed elements include: – Erythrocytes, or red blood cells (RBCs) – Leukocytes, or white blood cells (WBCs) – Platelets 5 © 2018 Pearson Education, Ltd. 5  Fractionation 6 © 2018 Pearson Education, Ltd. 6 Figure 19–1 The Composition of Whole Blood (Part 1 of 2). PLASMA A Fluid Connective Tissue Blood is a fluid connective tissue with a unique composition. It consists of a matrix called plasma (PLAZ-muh) and formed elements (cells and cell Plasma, the fluid matrix of blood, makes up fragments). The term whole blood refers 46−63% of the volume of whole blood. In many to the combination of plasma and the respects, the composition of plasma resembles that of interstitial fluid. This similarity exists formed elements. The cardiovascular because water, ions, and small solutes are system of an adult male contains 5−6 continuously exchanged between plasma liters (5.3−6.4 quarts) of whole blood. An and interstitial fluids across the walls of adult female contains 4−5 liters (4.2−5.3 capillaries. The primary differences between quarts). The sex plasma and interstitial fluid involve (1) the levels of respiratory gases (oxygen and differences in blood volume primarily reflect carbon dioxide, due to the respiratory activities of tissue cells), and (2) the 7% differences in average concentrations and types of dissolved body size. proteins (because plasma proteins cannot cross capillary walls). Plasma Plasma Proteins 1% Other Solutes 55% (Range 46-63%) Water 92% consists of + Formed Elements <.1% Platelets 45% White Blood Cells (Range 37−54%) Red Blood Cells <.1% Formed elements are blood cells and cell fragments that are suspended in plasma. These elements account for 37−54% of the volume of The hematocrit whole blood. Three types of formed elements 99.9% (he-MAT-ō-krit) is the exist: platelets, white blood cells, and red blood cells. Formed elements are produced through the percentage of formed process of hemopoiesis (hē-mō-poy-Ē-sis), elements in a sample of also called hematopoiesis. Two populations of blood. The normal stem cells—myeloid stem cells and lymphoid hematocrit, or packed cell stem cells—are responsible for the production of volume (PCV), in adult males is 46 FORMED formed elements. and in adult females is 42. The sex difference in hematocrit primarily reflects the fact that androgens (male hormones) stimulate red blood cell production, whereas estrogens (female ELEMENTS hormones) do not. 7 © 2018 Pearson Education, Ltd. 7  Blood components Amino acids Albumins Water Proteins Globulins Ions Glucose Fibrinogen is BLOOD composed Plasma Organic such as of molecules Lipids Trace elements Nitrogenous and vitamins waste CO2 Gases such as O2 Figure 16-1 (1 of 2) 8  Lymphocytes Red blood cells Monocytes is Cellular White BLOOD composed include of elements blood cells Neutrophils Platelets m 0 Eosinophils 5 10 15 Basophils 9 Haematocrit What is haematocrit (Ht or Hct) and packed cell volume (PCV)? Sex variations in hematocrit Normal values – males = 0.42 - 0.52 AND females = 0.36 - 0.48. 10  Plasma = 55% of whole blood Platelets “Buffy coat”