How do you define light cycle?​

Explanation:

The period of light that a subject is exposed to in a period of time, usually expressed as the amount of time in a 24 hour cycle. (

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.