Question

Select the correct statement.
i) Thoracic chamber is an open chamber filled with air.
ii) Thoracic chamber is built by dorsal ribs, ventral vertebral column, lower diaphragm and a lateral sternum.
iii) Any change in the thoracic cavity volume is not reflected in the lung cavity because of the anatomical setup of the lungs in the thorax.
iv) Humans can’t directly alter the pulmonary volume.

• A. Only i is correct
• B. Both ii and iii are correct
• C. Only iv is correct
• D. All are correct

Answer 1

The correct option is C Only iv is correct

The human respiratory system consists of a pair of vascularised structures called lungs. These lungs are located in an air-tight chamber termed as the thoracic (the area between the neck and the abdomen) chamber. This chamber is covered or built by a vertebral column (backbone) dorsally, sternum (breastbone) ventrally, ribs (12 pairs of bones) laterally, and a thin muscular dome-shaped diaphragm. The anatomical setup (structural arrangement) in the thoracic cavity is built in such a way that any change which take place in the cavity results in the changes in the lung cavity. This kind of arrangement is crucial for breathing as humans can’t directly modify the volume of the lungs because of the difference of closed packed structure of the thoracic cavity.