Thoracic cage
The skeleton of the rib cage (cavea thoracis . Don't mix cavea — cage, with the cavum — cavity) consists of the twelve thoracic vertebrae , ribs with their cartilages, and the sternum . The rib cage may look stiff, but it is a quite flexible structure with the complex motion behavior during lateral bending and rotation of the spine* .
* Lee DG. Biomechanics of the thorax – research evidence and clinical expertise. Journal of Manual & Manipulative Therapy. 2015;23(3):128-138.
The axial skeleton of the body. Multiple views
The axial skeleton includes all bones that naturally rotate around the vertical axis of the body: the skull with the auditory ossicles, hyoid bone , spine , thoracic cage, and pelvis . The vertical rotational axis of other bones (appendicular skeleton) does not coincide exactly the vertical axis of the body.
The anterior aspect of the rib cage
Note the costal arch made by fused costal cartilages of 7th , 8th , 9th , and sometimes also 10th rib* .
The list of terms:
Vertebra thoracica I & XII – First and twelveth thoracic vertebra
Manubrium sterni
Cartilago costalis I – Costal cartilage of the first rib
Costa prima – First rib
Costa secunda – Second rib
Angulus sterni – Sternal angle
Corpus sterni – Body of sternum
Cartilago costalis II–X – Costal cartilage II–X
Costa III–XII – Rib III–XII
Spatium intercostale I–III – First, second and third intercostal space
Arcus costalis – Costal arch
Angulus infrasternalis – Infrasternal angle
Planum subcostale – Subcostal plane
* Patel A, Privette A, et al. Anatomy of the anterior ribs and the composition of the costal margin: a cadaver study. J Traum Acute Care Surg, 2023, 95(6):875–879.
Oblique superior aspect of the rib cage. The thoracic inlet.
The list of terms:
Apertura thoracis superior – Superior thoracic aperture (thoracic inlet)
Manumbrium sterni
Incisura jugularis – Jugular notch
Incisura clavicularis – Clavicular notch
Cartilago costae I – Costal cartilage of the first rib
Corpus costae I – Body of the first rib
Caput & collum costae I – Head and neck of the first rib
Articulatio capitis costae – Joint of rib head
Corpus vertebrae Th 1 – Body of the first thoracic vertebra
Bottom view of the rib cage. The thoracic outlet.
The list of terms:
Apertura thoracis inferior – Inferior thoracic aperture (thoracic outlet)
Processus xiphoideus – Xiphoid process
Arcus costalis – Cosotal arch
Costal cartilage XI – Costal cartilage of the eleventh rib
Costa & cartilago costae XII – Twelfth rib with costal cartilage
Corpus vertebrae thoracicae XII – Body of the twelfth toracic vertebra
Cavitas thoracis – Thoracic cavity
Sulcus pulmonalis thoracis – Pulmonary sulcus of thorax
360° rotation of the rib cage
First published: May/2020
Last update: 15/Jan/2024