Upload
dalton
View
34
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Blood Physiology Professor A.M.A Abdel Gader MD, PhD, FRCP (Lond., Edin), FRSH (London) Professor of Physiology , College of Medicine & The Blood Bank, King Khalid University Hospital King Saud University Riyadh. BLOOD. Lecture # 1 & 2 Topic: Red Blood Cells (RBCs). - PowerPoint PPT Presentation
Citation preview
Blood Physiology
Professor A.M.A Abdel GaderMD, PhD, FRCP (Lond., Edin), FRSH (London)Professor of Physiology, College of Medicine
&The Blood Bank, King Khalid University
Hospital King Saud University
Riyadh
BLOOD
Lecture # 1 & 2Topic: Red Blood Cells (RBCs)
• Composition & functions of the Blood• Morphological Features of RBCs.• Production of RBCs• Regulation of production of RBCs• Nutritional substances need for RBC
production• Haemoglobin• (Iron metabolism)
Sites of blood formation
• Adults………….. Bone Marrow(Flat bones)
• Children …………. Bone Marrow(Flat & long bones)
• Before Birth: …. Bone Marrow Liver & spleen,lymph
nodes
• Fetus 1st 4 months …Yalk Sac
Production of RBC-cont.
Monophyletic theory of cell formationMonophyletic theory of cell formation
Red blood cells
Genesis of RBC
Hematopoiesis
(17.9)
Erythropoiesis, (Formation/genesis of RBC)
Growth factors (inducers):Control growth and maturation of stem cells:
– Interleukin-3– Erythropoeitin– Granulocyte stimulating factor
(GSF)
Production of Erythrocytes: Erythropoiesis
Figure 17.5
Erythropoiesis, (Formation/genesis of RBC)
– Stages of RBC developmentPluripotential haemopoietic STEM CELL
Committed Stem cell
Proerthroblast
early, intermediate and late normoblast
Reticulocytes
Erythrocytes
MaturatioMaturation n
SequenceSequence
Stages of differentiation of RBC
Features of the maturation process of RBC
1. Reduction in size
2. Disappearance of the nucleus
3. Acquisition of haemoglobin
Lecture # 1 & 2Topic: Red Blood Cells (RBCs)
• Composition & functions of the Blood• Morphological Features of RBCs.• Production of RBCs• Regulation of production of RBCs• Nutritional substances need for RBC
production• Haemoglobin• (Iron metabolism)
•Control of Erythropoiesis
Control of Erythropoiesis
• Erythropoiesis is stimulated by erythropoietin hormoneStimulated by:
• Hypoxia (low oxygen)– Anaemia– Hemorrhage– High altitude– Lung disease– Heart failure
Role of the kidneys in RBC formation
Tissue oxygenation and RBC formation
Control of erythropoiesis Cont.
• Erythropoietin•glycoprotein•90% from kidneys 10% liver•Stimulates the growth of: early RBC-committed stem cells•Can be measured in plasma & urine•High level of erythropoietin
–anemia –High altitude–Heart failure
Maturation Maturation TimesTimes
Control of erythropoiesis cont.
Other hormones– Androgens, Thyroid, cortisol &
growth hormones are essential for red cell formation
– Deficiencies of any one of these hormones results in anaemia
Control of erythropoiesis
Erythropoitein- Mechanism of production of
Hypoxia, (blood loss)
Blood O2 levels
Tissue (kidney) hypoxia
Production of erythropoietin
plasma erythropoietin
Stimulation of erythrocytes production
Erythrocyte production
Lecture # 1 & 2Topic: Red Blood Cells (RBCs)
• Composition & functions of the Blood• Morphological Features of RBCs.• Production of RBCs• Regulation of production of RBCs• Nutritional substances need for RBC
production• Haemoglobin• (Iron metabolism)
Nutritional requirements for RBC formation
1. Amino acid – HemoGlobin
2. Iron – HemoGlobin – Deficiency small cells
(microcytic anaemia )
Nutritional requirements for RBC formation cont.
3. Vitamins• Vit B12 and Folic acid
– Synthesis of nucleoprotein DNA
– Deficiency macrocytesmegaloblastic (large) anemia
• Vit C– Iron absorption
Production of Erythrocytes: Erythropoiesis
Figure 17.5
Vitamin B12 & Folic acid
• Important for cell division and maturation
• Deficiency of Vit. B12 > Red cells are abnormally large (macrocytes)
• Deficiency leads:– Macrocytic (megaloblastic)
anaemia
• Dietary source: meat, milk, liver, fat, green vegetables
Vitamin B12• Absorption of VB12 needs
intrinsic factor secreted by parietal cells of stomach
• VB12 + intrinsic factor is absorbed in the terminal ileum
• Deficiency arise from– Inadequate intake– Deficient intrinsic factors
•Pernicious anaemia
Nutritional requirements for RBC formation cont.
–Essential elements•Copper, Cobalt, zinc, manganese, nickel
•Cobalt Erythropoietin
ANAEMIAS
–Definiation•Decrease number of RBC•Decrease Hb
–Symptoms: Tired, Fatigue, short of breath,(pallor, tachycardia)
Causes of anaemia1. Blood Loss
– acute accident– Chronic ulcer, worm
2. Decrease RBC production– Nutritional causes
• Iron microcytic anaemia•VB12 & Folic acid megaloblastic
anaemia – Bone marrow destruction by cancer,
radiation, drugs Aplastic anaemia.
3. Haemolytic excessive destruction – Abnormal Hb (sickle cells)– Incompatible blood transfusion
•The most common cause for a hypochromic microcytic anemia is iron deficiency. The most common nutritional deficiency is lack of dietary iron. Thus, iron deficiency anemia is common. Persons most at risk are children and women in reproductive years (from menstrual blood loss and from pregnancy).
The most common cause for a hypochromic microcytic anemia is iron deficiency. The
most common nutritional deficiency is lack of dietary iron. Thus, iron deficiency anemia is common. Persons most at risk are children and women in reproductive
years (from menstrual blood loss and from pregnancy)
Macrocytic anemia
The RBC are almost as large as the lymphocyte. Note the hypersegmented neurotrophil. There
are fewer RBCs.
The RBC's here are smaller than normal and have an increased zone of central pallor. This is indicative of a hypochromic (less hemoglobin in each RBC) microcytic (smaller size of each RBC) anemia. There is also increased anisocytosis (variation in size) and poikilocytosis (variation in shape).
Macrocytic anemia
Note the hypersegmented neurotrophil and also that the RBC are almost as large as the lymphocyte. Finally, note that there are fewer RBCs.
Polycythemia
– Increased number of RBC– Types:
•True or absolute– Primary (polycythemia rubra vera):
uncontrolled RBC production– Secondary to hypoxia: high altitude,
chronic respiratory or cardiac disease
•Relative– Haemoconcentration:
» loss of body fluid in vomiting, diarrhea, sweating