Respiratory System
Biology · श्वसन तंत्र · 15 facts
Respiration: breathing in O2 and releasing CO2; energy production
Path: nose->pharynx->larynx->trachea->bronchi->bronchioles->alveoli
Nose: filters, warms, moistens air; nasal hair traps dust
Larynx: voice box; contains vocal cords for speech
Trachea(windpipe): C-shaped cartilage rings keep it open
Lungs: spongy organs in chest; right(3 lobes), left(2 lobes)
Alveoli: tiny air sacs; site of gas exchange(O2 in, CO2 out)
Diaphragm: dome-shaped muscle; contracts for inhalation
Haemoglobin in RBC carries O2 from lungs to tissues
Breathing rate: 15-20 breaths/minute in adults at rest
Aerobic respiration: C6H12O6+6O2->6CO2+6H2O+ATP (with oxygen)
Anaerobic: without O2; in muscles produces lactic acid(cramps)
Asthma: inflammation of bronchi; breathing difficulty; common in India
Vital capacity of lungs: maximum air inhaled after full exhalation (~4-5 litres)
Tobacco smoke damages alveoli causing emphysema; major health risk in India