the condition in which the heart muscle does not get enough oxygen-rich blood because of a narrowing or blocking of the coronary artery is called

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

it's d - life cycles - apex