MEDICAL PHYSIOLOGY

Detailed explanation-1: -When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.

Detailed explanation-2: -Breathing in When you breathe in, or inhale, your diaphragm contracts and moves downward. This increases the space in your chest cavity, and your lungs expand into it. The muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.

Detailed explanation-3: -Since the lungs are connected to the chest wall via the pleura, the negative intrapleural pressure pulls the lungs towards the chest wall leading to an increase in lung volume. As lung volume increases, pressure decreases as per Boyle’s law.

Detailed explanation-4: -During inspiration, the diaphragm and external intercostal muscles contract, causing the rib cage to expand and move outward, and expanding the thoracic cavity and lung volume. This creates a lower pressure within the lung than that of the atmosphere, causing air to be drawn into the lungs.

Detailed explanation-5: -The action of the inspiratory muscles results in an increase in the volume of the thoracic cavity. As the lungs are held against the inner thoracic wall by the pleural seal, they also undergo an increase in volume. As per Boyle’s law, an increase in lung volume results in a decrease in the pressure within the lungs.