The figure shows a diagrammatic view of human respiratory system with labels A, B, C and D. Select the option, which gives correct identification and main function and/or characteristic.
A - trachea - long tube supported by complete cartilaginous rings for conducting inspired air
B - pleural membrane-surround ribs on both sides to provide cushion against rubbing
C - alveoli - thin walled vascular bag-like structures for exchange of gases
D - lower end of lungs - diaphragm pulls it down during inspiration
C.
C - alveoli - thin walled vascular bag-like structures for exchange of gases
C - Alveoli are thin-walled vascular bag-like structures for exchange of gases.
A - Trachea or wind pipe is an air conduying tube through, which transport of gases takes place.
B - pleural membrane is double layered, which reduces friction on the lung surface.
D - diaphragm is involved in the inspiration and expiration process of breathing.
