Grade 3 | Science | Respiratory system, Human Body, Olympiad, CBSE, ICSE, SOF, ITO
Respiratory system begins at nose or mouth.
We inhale oxygen-rich air and exhale carbon dioxide rich air.
Air goes to our lungs via trachea. The trachea is a long hollow tube that connects larynx and pharynx to lungs.
Lungs are like bags. Lungs have thin tube-like structures known as bronchioles.
Bronchioles have small ball like sacs at the end called as alveoli. Exchange of gases takes place at alveoli.
Diaphragm muscles along with abdominal muscles help our lungs in expansion and contraction.