Rib cage

Rib cage
The human rib cage (Source: Gray's Anatomy of the Human Body, 20th ed. 1918.)
Protection on the rib cage of the heart, lungs and diaphragm. The shaded areas indicate the extent of the pleural cavities not filled by the lungs.
Details
Identifiers
Latin	cavea thoracis
MeSH	D000070602
TA98	A02.3.04.001
TA2	1096
FMA	7480
Anatomical terminology [edit on Wikidata]

The rib cage is an endoskeletal enclosure in the thorax of most vertebrate animals that comprises the ribs, vertebral column and sternum, which protects vital organs such as the heart, lungs and great vessels. The circumferential enclosure formed by left and right rib cages, together known as the thoracic cage, is a semi-rigid bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdles to form the core part of the axial skeleton.

A typical human thoracic cage consists of 12 pairs of ribs and the adjoining costal cartilages, the sternum (along with the manubrium and xiphoid process), and the 12 thoracic vertebrae articulating with the ribs. The thoracic cage also provides attachments for extrinsic skeletal muscles of the neck, upper limbs, upper abdomen and back, and together with the overlying skin and associated fascia and muscles, makes up the thoracic wall.

In tetrapods, the rib cage intrinsically holds the muscles of respiration (diaphragm, intercostal muscles, etc.) that are crucial for active inhalation and forced exhalation, and therefore has a major ventilatory function in the respiratory system.