-Renad Habahbeh. -Shahd Alqudah. - Saleem. 1 P a g e

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1 -1 -Renad Habahbeh -Shahd Alqudah - Saleem 1 P a g e

Introduction: *Hematology and lymph system (MLS): it is a branch of medicine concerned with the study, diagnosis, prevention and treatment of blood and lymph disorders.

2 Introduction: *Hematology and lymph system (MLS): it is a branch of medicine concerned with the study, diagnosis, prevention and treatment of blood and lymph disorders. In MLS physiology, we are concerned about body fluids and the concept of the blood, we will talk about each type of blood cells and haematopoiesis, we will study also gas transport and homeostasis. What is blood? *Blood is a specialized type of connective tissue, In the average 70-Kg man, the total body water is about 65% of the body weight or about 45 litres of fluid, 5 litres of these fluids are blood. -Blood is composed of: 1- Blood plasma % Blood cells (also called formed elements) %45. *If we take a tube full of uncoagulated blood (doesn t clot) and we centrifuge it for (5-10) minutes, we find that 45 percent is cells and 55 percent is plasma. -The fore mentioned part was copied from 2015's sheets since Dr. Saleem was all over the place- *Blood cells: - Used volume units when counting blood cells are: 1)Microlitre (μl) = Millimetre cubed (mm³) 2) Millilitres (ml) 3) Litres (L). 2 P a g e

3 **Erythrocytes, leukocytes and Platelets count/litre are for memorizing.** **Platelets are also called thrombocytes. Normal red blood celll -erythrocytes- values are (number of cells/ Volume unit): - In males: about 5 million cells per μl ( ) - In females: about 4.5 million cells per μl ( ) Males have higher RBCs count than females because of hormones like androgens (I.e.: testosterone) which stimulate RBC synthesis(erythropoiesis ) (Dr. Saleem repeated this several times so it's probably an important piece of information). *Leukocytes with their subtypes (Neutrophils, eosinophils, basophils, lymphocytes and monocytes) will be discussed later. *Thrombocytes will, also, be discussed later. Blood Plasma: Blood plasma mainly consists of water, with (90-92)% of it is water and the rest (8-10)% being : electrolytes (less than 1%), gases (also 1%), nutrients ( 3%) [glucose, amino acids,..], Waste products (1%) [Urea, Creatinine, uric acid, bilirubin], plasma proteins (6%-8%). -Main plasma proteins: 3 P a g e

4 1. albumins (4.5 g/100 ml ) 2. Fibrinogens (0.3 g/100 ml) 3. globulins (2.5 g/100 ml) 4. prothrombins. *There are over 1400 identified plasma proteins but these are the fore mentioned ones are the important ones. Also, almost all plasma proteins are produced in the liver, so any disease that affect the liver will affect the production of those proteins, (Special type of globulins, Immunoglobulins have another source of production which is the lymphocytes). -Functions of plasma proteins: 1. Transport functions (for gases, hormones, nutrients... etc.) 2. Defence functions by the immunoglobulins (produced by lymphocytes) 3. Blood coagulation (fibrinogen and prothrombin) 4. Reserving body proteins. 5. Viscosity mainly due to fibrinogen and globulins regarding plasma proteins. (when we talk about blood,red blood cells have the greatest effect on blood viscosity but when we solely talk about plasma, albumin has the greatest effect). 6. Exchange of fluids between the capillaries and tissues by the oncotic or colloidal pressure which is mainly produced by albumins. Oncotic pressure normal value ranges from millimeter mercury (mmhg). Extra note: albumin contributes approximately 22 mmhg to this oncotic pressure. -ph of blood plasma: *Normal blood ph range: ( ), and the neutral point is 7.4. *The ph of the gastric juice is less than that of lemon juice. (more acidic) **The ph scale of blood is different than that of water. (why?) Different neutral point (which is 7.4 instead of 7). ** **Below 7.4 acidic, Above 7.4 basic.** -When ph levels are above 8 or below 6.8 : 1.eznymes are denaturated and their function is disturbed. The most importat enzyme that will be affected is Na + /K + -ATPase (sodium-potassium pump). 2. over or hypo-excitability of CNS. 4 P a g e

5 3.Affects H + -Potassium pumps (because there is a close relationship between the hydrogen atoms and the potassium, they re always together), so entry and exit of Potassium is altered and that,in turn, disturbs the internal environment. *Complete and incomplete proteins: Complete proteins provide all essential amino acids while incomplete proteins, you guessed it!, do NOT provide all essential amino acids. - The most important sources of complete proteins are: eggs, chicken and fish. - Incomplete proteins are provided by vegetables. Vegetarians are exposed to develop amino acid deficiency because they don't take complete proteins. Blood *Blood distribution: *Variation in blood volume: -Blood volume varies physiologically due to -> 1.gender; there is a difference between males and females (males have a higher blood volume), due to hormones (androgens). 2.pregnancy; pregnant women have more plasma and blood volume.(hormoal change) 3.muscular exercise; increases blood volume. 4. posture; in standing position there is a reduction in blood volume of about 15% in which this 15% "goes" into interstitial fluid. 5. blood pressure; rising blood pressure lowers blood volume. 5 P a g e

6 6. Altitude; increases blood volume. (low O 2 concentration -hypoxia, stimulates RBCs production which in turn increases blood volume). 7. excitement; in which case adrenaline is released increasing the blood volume. 8. contraction of spleen, as it contains blood. *RBCs (Erythrocytes): -RBCs are: circular, biconcave, anucluated. Sometimes minor changes in their shape occur to aid in passing through capillaries. They don't leave capillaries. **Dimensions of RBCs: 1- MCV (the most important parameter): MCV (mean corpuscular * volume) which means the average volume of red blood cells.the usual normal range (80-90) µm³ OR fl. It might be lower than that reaching (78,79) and sometimes it reaches (91,92) that is normal as well. *fl ( femtoliter ) = µm³ (micron cubic). 2- surface area: normal range µm² 3- diameter: µm -When the MCV changes, the other dimensions also change. * Corpuscular is another name of RBCs. -Erythrocytes usually counts for: 5 million cell / µl in males 4.5 million cell / µl in females. 5 million cell / µl in humankind in general.-without specifying a gender-. 6 P a g e

7 * µl= microliter -> the most common used unit for RBC count. (Dr.Salem kept going back to mention this so I think it may be of some importance to him), 45% *Recalling the shape of RBCs, a biconcave desk, therefore, around 2% of plasma is trapped in the RBCs "column". = trapped plasma Blood parameters: 1. RBCs count. 2. Haematocrit. 3. Haemoglobin content. **In new-born babies all three parameters of blood are higher than in normal adults. This happens due to: 1. Placental oxygenation which will later shift into pulmonary oxygenation (breathing through oneself lungs) 7 P a g e

8 2. Fetal hemoglobin which will later turn into adult haemoglobin. When fetal oxygenation and fetal haemoglobin turn into pulmonary oxygenation and adult haemoglobin respectively during their 7 th month after birth, blood parameters are normalized. -Haematopoiesis: production of all blood cells. - Erythropoiesis: production of blood cells mainly RBCs. both of them are vital to keep the number of circulating blood cells in their normal range. * In fetal life (prenatal) you will notice that erythropoiesis during the first 2 months occurs mainly in the yolk sac, then in the liver (and to a lesser extent, in the spleen) At the beginning of the 5th month the bone marrow (primarily) and the lymph nodes are responsible for erythropoiesis. * After birth the bone marrow is the only site for production of blood cells. * During childhood bone marrow of all bones produce blood cells. * At the age of 18 in females and 20 in males (adulthood) blood cell production is limited to some bone marrow found in the vertebrae, pelvis, sternum, ribs, and especially the ends of long bones like the femur, tibia, ulna, and radius, as well as the scapula and the clavicle. [the order of their contributions is important] Regulation of erythropoiesis: Factors that regulate RBCs and keep their number relatively constant and normal: 8 P a g e

1. Oxygen supply: when the amount of oxygen decreases (hypoxia) the number of RBCs increases to compensate for this reduction, and vice versa with hyperoxia which occurs with people who live around

9 1. Oxygen supply: when the amount of oxygen decreases (hypoxia) the number of RBCs increases to compensate for this reduction, and vice versa with hyperoxia which occurs with people who live around the sea level (RBC count is lower among them). -Hypoxia can be caused by low blood volume, anaemia, low haemoglobin, poor blood flow, and pulmonary diseases. -Hypoxia does not directly affect the blood marrow; it affects the cells in the kidneys which sense oxygen levels in the body, and when oxygen levels are low these cells produces erythropoietin and stimulates erythropoiesis. Erythropoietin - a glycoprotein hormone that enhances the production of RBCs by affecting erythrocyte stem cells until hypoxia is relieved. - Promotes the formation of red blood cells by the bone marrow. - Half-life: 10 hours. - 90% is produced by the kidney and 10% by the liver and a very little amount is produced by the spleen if any. -Traceable in both plasma and urine - The duration of erythropoietin activity is 3-6 days and is functional for 6 hours. Erythropoiesis : - In all stages haemoglobin is synthesized. 9 P a g e

10 - The last stage of erythropoiesis is reticulocytes. These cells contain fragments of their nuclei (mature RBCs don t have nuclei) and synthesize the haemoglobin. -They are present in the bone marrow and remain there for 2-3 days before they are released into the circulation. - Reticulocytes don t contain a proper nucleus but they can synthesize the remaining haemoglobin as reticulocytes, which are immature erythrocytes. -Once they complete the synthesis of haemoglobin they will become mature RBCs. - Haemoglobin synthesis does not occur in mature RBCs - If Reticulocytes make up 1-2% of RBCs then erythropoiesis is normal, below erythropoiesis is low. Erythropoiesis is low when reticulocytes make up less than 2% of RBCs - In the bone marrow: the number of reticulocytes = the number of nucleated cells (erythroblast cells) **The number of reticulocytes in the circulation is less than their number in the bone marrow. In haemolytic anaemia, the reticulocyte percentage is high, low RBC count (abnormal condition)** The End. 10 P a g e

Zahraa Muneer. Enas Ajarma. Saleem

Zahraa Muneer. Enas Ajarma. Saleem 2 Zahraa Muneer Enas Ajarma Saleem Blood parameters: 1. RBCs count 2. Haematocrit 3. Haemoglobin content In new-born babies all three parameters of blood are higher than in normal adults. This happens