Describe in brief the functions of ribs and diaphragm in breathing.

The ribs and diaphragm are key components of the respiratory system, working together to facilitate the process of breathing, which involves inhalation (breathing in) and exhalation (breathing out).

Ribs:

The ribcage consists of 12 pairs of ribs that form a protective structure around the thoracic (chest) cavity.
The ribs are attached to the spine at the back and curve around to the front, connecting to the sternum (breastbone) via cartilage.
During inhalation, the ribcage expands. This is achieved through the action of intercostal muscles, which are located between the ribs. When these muscles contract, they lift and move the ribs outward, increasing the volume of the thoracic cavity.
The expansion of the thoracic cavity lowers the air pressure within the lungs, allowing air to flow in from the external environment to equalize the pressure.
Diaphragm:

The diaphragm is a dome-shaped, muscular partition separating the thoracic cavity from the abdominal cavity.
During inhalation, the diaphragm contracts and flattens. This increases the vertical dimension of the thoracic cavity.
Flattening of the diaphragm enlarges the thoracic cavity, reducing the air pressure within the lungs and causing air to be drawn into the respiratory tract.
During exhalation, the diaphragm relaxes, returning to its dome shape. This reduces the thoracic cavity's volume, increasing the air pressure within the lungs and causing air to be expelled.
Together, the ribs and diaphragm coordinate their actions to create changes in thoracic cavity volume, allowing for the inhalation and exhalation of air. This process is crucial for the exchange of oxygen and carbon dioxide in the respiratory system.