Ribs (or rib bones)12 pairs of curved bones that are attached to the vertebrae at the back. The 10 upper pairs of ribs are attached to the stermum at the front, while the lower two pairs are unattached or floating
Intercostal muscles Two sets of muscles found between the ribs, which Help ver move the rib cage
Pleural cavity A narrow, air-tight cavity
Diaphragm A sheet of muscle that separates the thorax from Its mo the abdomen
Nasal cavity A cavity behind the nose that is lined by a mucous membrane which secretes mucus from the globlet cells it contains.