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Thorax Cheat Sheet (DRAFT) by

Thoracic cage & Intercostal spaces, Mediastinum Pleura, Lungs & Bronchial tree Sternum, Ribs & Thoracic vertebrae Pericardium & Heart Innervation & Blood supply to the heart Pericardium & Heart Radiological anatomy of thorax Posterior mediastinum & Posterior thoracic wall

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Thoracic cavity compar­tments

Left pulmonary cavity
Right pulmonary cavity


Xiphoid process
The junction of the manubr­ios­ternal joint forms the sternal angle of Louis, the plane of which lies between T4 and T5.
Many important events occur at this angle:
1. Beginning and end of aortic arch
2. Tracheal bifurc­ation
3. Confluence of azygous vein and SVC
4. Thoracic ducts deviates left
5. Ligamentum arteriosum lies on this plane
6. Division of pulmonary trunk
7. Location of cardiac plexus

Function of Thorax

Provides attachment for muscles of upper limb, abdomen, neck, back and respir­ation
Provides mechanics for breathing and resists negative internal pressures created by the elastic recoil of the lungs and inspir­atory movements

Vertebral Features

Bilateral costal facets
Articu­lates with heads of ribs
Costal facets on transverse processes
Articu­lates with tubercles of ribs
Spinous processes
Slope inferiorly and overlap with vertebra below and thus cover the intervals between the laminae of the adjacent vertebra which prevents sharp objects from entering the vertebral canal and injuring the spinal cord

Rib Types

True (verte­bro­ste­rnal) ribs
Attach directly to sternum through their own costal cartilages (vertebrae to sternum)
False (verte­bro­cho­ndral) ribs
Attach indirectly to sternum via cartilage of rib above them (vertebrae to cartilage)
Floating (verte­bral) ribs
Do not connect to sternum (vertebrae only)
Interior of ribs is red bone marrow (hemat­opo­ietic tissue) which forms blood cells

Rib Classi­fic­ation

Typical ribs
Have a head (has 2 facets), neck, tubercle (smooth articular surface for articu­lation with transverse process of vertebra and rough articular surface for attachment of costot­ran­sverse ligament), body (with costal groove which gives protection to interc­ostal nerve and vessels).
Atypical ribs
Lack either one or more of the features of typical ribs
The interc­ostal spaces are named for the rib number forming the superior border, and the interc­ostal blood vessels and nerves are named for the interc­ostal space number in which they are found.
Space below the 12th rib: subcostal space, thus T12 is the subcostal nerve.