Biology
How do the following contribute in inspiration during breathing?
- Ribs
- Diaphragm
Answer
- During inhalation, the ribs move upwards and outwards due to contraction of the external intercostal muscles stretched between them. This enlarges the chest cavity.
- The diaphragm flattens, expanding the chest cavity lengthwise. This increases the volume and decreases the pressure inside the lungs. Air is then drawn in from outside to equalize the pressure.
Related Questions
State whether the following statements are true (T) or false (F):
- Strenuous physical exercise may cause fatigue due to accumulation of CO2 in the blood.
- No CO2 is produced in anaerobic respiration in the human body.
- Breathing and gaseous transport are one and the same thing.
- CO2 is transported to the lungs by the blood in two forms: as bicarbonates and as carbamino-haemoglobin.
- Tissue respiration means chemical changes occurring inside the cell.
Match the items in Column I with those in Column II
Column I Column II Nasal chamber Production of voice Epiglottis C-shaped rings Air-sacs Warms air Lungs Drives mucus Larynx Closes wind-pipe during swallowing Trachea Network of capillaries Cilia Spongy and elastic Match the lung capacities in Column I with the quantities given in Column II.
Column I Column II Residual air 4500 mL Vital capacity 6000 mL Total lung capacity 1500 mL Dead air space 150 mL Mention any two points of difference in the quality of inspired and expired air.