Thoracic cage notes

Thoracic Cage

Sternum

• Located along the midline.

• Divided into three parts:

  • Manubrium (Handle)

  • Body

  • Xiphoid process (Sword-like)

Manubrium

• Features a notch along the superior edge called the Jugular or Suprasternal notch.

Joints

• Between manubrium and body: Manubriosternal joint, also called the angle of Louis.

• Between body and xiphoid process: Xiphisternal joint.

Ribs

• Most people have 12 ribs, numbered 1-12 from superior to inferior.

• Ribs connect from bone to cartilage, which is called Costal Cartilage, towards the sternum.

Thoracic Apertures

Superior Thoracic Aperture (Thoracic Inlet)

• Structures pass through the neck and thorax via this opening.

• Borders:

  • T1 Vertebra

  • Edges of the first rib

  • Manubrium

Inferior Thoracic Aperture

• Borders:

  • T12 vertebra

  • 12th rib

  • Cartilaginous ends of ribs 7-10

  • Xiphoid process (anteriorly)

Rib Classification

• Ribs 1-7: True ribs, directly attached to the sternum.

• Ribs 8-12: False ribs, not directly attached to the sternum.

• Ribs 11 and 12: Floating ribs.

• Ribs 8, 9, and 10 are attached to each other and the 7th rib via Interchondral joints.

• Ribs attach to the vertebrae posteriorly.