Biology
During inspiration in humans the diaphragm and external intercostal muscles:
- Both contract
- Contract and relax respectively
- Both relax
- Relax and contract respectively
Respiratory System
9 Likes
Answer
Both contract
Reason — During inspiration the diaphragm contracts and moves downward, increasing the vertical space in the thoracic cavity. The external intercostal muscles also contract, pulling the ribs upward and outward, increasing the volume of the chest cavity. This increases the thoracic volume and reduces pressure, allowing air to flow into the lungs.
Answered By
6 Likes
Related Questions
The muscular sheet which separates the thoracic and abdominal chamber of the human body is:
- Peritoneum
- Diaphragm
- Parietal pleura
- Visceral pleura
Which of the following produces mucus in the respiratory passage?
- Ciliated cells
- Air sacs
- Goblet cells
- Tertiary bronchi
Assertion (A): The product of combination of carbon dioxide and haemoglobin is termed as carboxyhaemoglobin.
Reason (R): RBCs carry carboxyhaemoglobin from the tissue cells to blood capillaries. Hence, carbon dioxide gas is exhaled out.
- A is True and R is False.
- A is false and R is True.
- Both A and R are True.
- Both A and R are False.
Assertion (A): The entrance to the oesophagus is guarded by a flap called epiglottis.
Reason (R): Epiglottis closes the entrance of trachea at the time of swallowing food.
- A is True and R is False.
- A is False and R is True.
- Both A and R are True.
- Both A and R are False.