Circulatory System
Biology · परिसंचरण तंत्र · 16 facts
Heart: muscular pump; 4 chambers (2 atria + 2 ventricles)
Double circulation: blood passes through heart twice per circuit
Pulmonary: heart->lungs->heart (deoxygenated to oxygenated)
Systemic: heart->body->heart (oxygenated to deoxygenated)
Arteries: carry oxygenated blood away from heart(except pulmonary artery)
Veins: carry deoxygenated blood to heart(except pulmonary vein)
Capillaries: thinnest vessels; exchange of gases, nutrients at tissue level
Blood components: RBC(carry O2), WBC(fight infection), Platelets(clotting), Plasma
RBC: contain haemoglobin(iron-based); gives blood red colour
WBC: soldiers of body; fight germs; produced in bone marrow
Platelets: help in blood clotting at wound site
Blood groups: A, B, AB, O; discovered by Karl Landsteiner
AB: universal recipient; O: universal donor
Rh factor: Rh+ or Rh-; important in pregnancy and transfusion
Normal heart rate: 72 beats/minute; BP: 120/80 mmHg
Pacemaker(SA node): natural; controls heartbeat rhythm