An arterial condition in which there is thickening, hardening, and loss of elasticity of the walls of arteries—resulting in decreased blood supply—especially to the lower extremities and cerebrum is known as hardening of the arteries

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.