Question

Which feature makes lungs an efficient respiratory surface?

Answer 1

Answer:

large surface area due to millions of thinwslled alveoli.

Answer 2

Lungs:

• The alveoli of lungs make it an efficient respiratory system.

What are alveoli ?

▪ Alveoli are structural and functional unit of lungs

▪Alveoli consists of two types of cells called pneumocytes

▪Pneumocyte I helps in gaseous exchange

▪ Pneumocyte II helps secrets LECITHIN, which act as surfactant thereby reducing the surface tension of alveoli and keeps alveoli open for efficient gaseous exchange.

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Other feature of Lungs:

• The two lungs are covered by double layer pleura.

• The pleural fluid of lungs reduces the friction in surface of lungs and act as a shock absorber.

• Lungs are situated in the thoracic chamber which is automatically an air-tight chamber.

• The anatomical set up of lungs in thorax is such that any change in the volume of the thoracic cavity will be reflected in the pulmonary cavity. It makes sure that we can't directly alter the pulmonary volume. This arrangement is essential for breathing.