AP BIOLOGY

Detailed explanation-1: -The primary inspiratory muscles are the diaphragm and external intercostals .

Detailed explanation-2: -The diaphragm, a dome-shaped sheet of muscle that separates the chest cavity from the abdomen, is the most important muscle used for breathing in (called inhalation or inspiration).

Detailed explanation-3: -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-4: -When you breathe in, your diaphragm contracts (tightens) and flattens, moving down towards your abdomen. This movement creates a vacuum in your chest, allowing your chest to expand (get bigger) and pull in air. When you breathe out, your diaphragm relaxes and curves back up as your lungs push the air out.

Detailed explanation-5: -From a functional point of view, there are three groups of respiratory muscles: the diaphragm, the rib cage muscles and the abdominal muscles. Each group acts on the chest wall and its compartments, i.e. the lung-apposed rib cage, the diaphragm-apposed rib cage and the abdomen.