قناة سنة ثانية بشري (دفعة 53)

Cross-matching • Major cross-match: Mix recipient serum + donor RBCs. • If clumping occurs → incompatible. Rh System • Rh antigens: C, D, E, c, d, e (D is most important). • D present → Rh positive • D absent → Rh negative Population distribution • Whites: 85% Rh+, 15% Rh- • African blacks: ≈100% Rh+ Importance of Rh Factor 1. Transfusions • Rh+ person → can receive Rh+ or Rh-. • Rh− person → must receive Rh− only. • If Rh− receives Rh+: • 1st transfusion → sensitization (no major reaction). • 2nd transfusion → severe hemolysis.

ABO System • RBCs have antigens (agglutinogens): A and B. • Plasma has antibodies (agglutinins): α (anti-A) and β (anti-B). • Anti-A attacks antigen A, Anti-B attacks antigen B. • Antibodies are IgM and IgG; appear after 6 months of age. • Blood group depends on RBC antigens: • Antigen A → Group A • Antigen B → Group B • Antigens A + B → Group AB • No antigens → Group O • Genetically determined. Universal types • O = Universal donor (no antigens). • AB = Universal recipient (no antibodies). Prevalence • Most common: O • Least common: AB

ABO System • RBCs have antigens (agglutinogens): A and B. • Plasma has antibodies (agglutinins): α (anti-A) and β (anti-B). • Anti-A attacks antigen A, Anti-B attacks antigen B. • Antibodies are IgM and IgG; appear after 6 months of age. • Blood group depends on RBC antigens: • Antigen A → Group A • Antigen B → Group B • Antigens A + B → Group AB • No antigens → Group O • Genetically determined. Universal types • O = Universal donor (no antigens). • AB = Universal recipient (no antibodies). Prevalence • Most common: O • Least common: AB

3 . Blood Group : ⬇️⬇️⬇️⬇️

رست ونمشو للشيت الثالث ال blood group

هكي شيت ال RBC كمل ي شباب ♥️♥️.

13. Major Anemias Iron Deficiency Anemia • Low Hb • Microcytic • Low serum iron, ferritin, transferrin saturation • Most common anemia worldwide Aplastic Anemia • Bone marrow failure • Causes: • Radiation • Chemotherapy • Toxic chemicals • Autoimmune diseases • Idiopathic Megaloblastic Anemia • B12 or folate deficiency • Abnormal, large RBCs • Causes: pernicious anemia, gastrectomy, intestinal malabsorption Hemolytic Anemia • Fragile RBCs → rapid destruction • Normal or high RBC production • Examples: • Hereditary spherocytosis • Sickle cell anemia (HbS)

11. Anemia (general definition) • Low hemoglobin • WHO: • <13.5 g/dl (males) • <11.5 g/dl (females) 12. Types of Anemia A. Normocytic, Normochromic • Chronic disease • Hemolytic anemia • Acute blood loss • Aplastic anemia B. Microcytic, Hypochromic • Iron deficiency • Thalassemia • Chronic disease (rare) C. Macrocytic (Normochromic) • Vitamin B12 deficiency • Folate deficiency

9. Abnormal Hemoglobins • Carboxyhemoglobin → CO replaces O₂ • Methemoglobin → Fe³⁺ (cannot bind O₂) • Sulfhemoglobin → sulfur-bound Hb (irreversible, dangerous) • Thalassemia → defective/absent globin chains • Hemoglobin S (Sickle cell) → β-chain defect (valine replaces glutamic acid) 10. Nonfunctional Hemoglobins • Cause hypoxia and cyanosis (if >5 g/dl deoxyhemoglobin)