Hiccups are involuntary spasms of the diaphragm — a layer of muscle that sits directly under the lungs.

It also possesses a longitudinal septum, a horizontal layer of muscle and connective tissue that separates the dorsal and ventral compartments of the body.

The wing membranes also contained a thin layer of muscle, fibrous tissue, and a unique, complex circulatory system of looping blood vessels.

A therapist uses slow, deliberate strokes that focus pressure on layers of muscles, tendons or other tissues deep under the skin.

The exposed layers of muscles in her face were like the pages of an ancient book, or a pack of cards waiting to be reshuffled into another life.