3D CONTENT
3D OSTEOLOGY
3D THORAX

RIB CAGE ANATOMY

Author: Dr. Bogdan Leahu
← Thoracic Skeleton Ribs →
Rib cage anatomy 360-degree interactive viewer showing twelve pairs of ribs, true ribs, false ribs, floating ribs, and costal cartilages
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TABLE OF CONTENTS

RIBS CAGE

What is the rib cage?

  • Your rib cage typically consists of twelve pairs of ribs, with occasional variation
  • The first seven pairs, known as true ribs, attach directly to the sternum via costal cartilages, forming a supportive, flexible structure that aids your respiration and protects your vital organs
  • The lower five pairs are false ribs, where ribs eight to ten attach indirectly to the sternum via cartilage
  • Ribs eleven and twelve, called floating ribs, have no sternal connection

True Ribs (Ribs 1-7)

What are the true ribs?

  • First seven pairs of ribs
  • Attach directly to the sternum via individual costal cartilages
  • Also called vertebrosternal ribs
  • Provide primary structural support to your thoracic cage

False Ribs (Ribs 8-10)

What are the false ribs?

  • Ribs eight, nine, and ten
  • Attach indirectly to the sternum via the cartilage of the rib above
  • Also called vertebrochondral ribs
  • Contribute to the costal arch formation

Floating Ribs (Ribs 11-12)

What are the floating ribs?

  • Ribs eleven and twelve
  • Have no sternal attachment
  • Also called vertebral ribs
  • Pointed ends that are free in the musculature
  • Provide protection for your kidneys

COSTAL CARTILAGES

Costal cartilages showing bars of hyaline cartilage connecting ribs to sternum providing flexibility to thoracic wall
3D OSTEOLOGY
Costal Cartilages - Overview, Preview from the app. Licensed under CC BY-NC-ND 4.0. Sourced from 3D OSTEOLOGY.

What are the costal cartilages?

  • Costal cartilages are bars of hyaline cartilage that connect your ribs to the sternum or to each other
  • Provide flexibility to your thoracic wall necessary for respiration

Connections

Costal cartilage connections showing first seven pairs attaching to sternum and eighth to tenth ribs attaching to cartilage above
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Costal Cartilages - Connections, Preview from the app. Licensed under CC BY-NC-ND 4.0. Sourced from 3D OSTEOLOGY.

How do the costal cartilages connect?

  • First seven pairs connect directly to the sternum
  • Eighth, ninth, and tenth ribs attach to the cartilage above
  • Eleventh and twelfth pairs (floating ribs) have pointed ends without sternum attachment

Function

Costal cartilages demonstrating flexibility of thoracic wall facilitating thoracic wall expansion during respiration
3D OSTEOLOGY
Costal Cartilages - Function, Preview from the app. Licensed under CC BY-NC-ND 4.0. Sourced from 3D OSTEOLOGY.

What is the function of the costal cartilages?

  • Provides flexibility to your thoracic wall
  • Facilitates thoracic wall expansion during your respiration

COSTAL ARCH

Costal arch 360-degree viewer showing cartilages of seventh to tenth ribs curving upward to meet at xiphoid process
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Costal Arch - False Ribs, Preview from the app. Download 3D OSTEOLOGY for full 3D control—multiple views, x-ray mode, and unlimited zoom.

What is the costal arch?

  • Formed by the cartilages of the seventh to tenth ribs
  • Curves upward and forward to meet at the xiphoid process
  • Contributes to the flexibility of your thoracic wall
  • Accommodates your lung expansion during breathing

Costal Margin

What is the costal margin?

  • The lower edge of your costal arch
  • Forms the infrasternal angle at the xiphoid process
  • Important anatomical landmark for clinical examination

BIBLIOGRAPHY

1. Henry G, Warren HL. Osteology. In: Anatomy of the Human Body. 20th ed. Philadelphia: Lea & Febiger; 1918. p. 129–97.