Vetomica
Create free account

Dog · Set · Thorax

The ribs

Costae

Thirteen pairs, each a bony part and a cartilage. The useful facts about a rib are nearly all facts about where it stands in the series: how far down it reaches, how long it is, and what its cartilage joins.

Region
Thorax
Members
13
Own page
2
Named parts
6

How they differ along the set

What changes from one end of the series to the other, which is most of what there is to know about any one of them.

  • Usually thirteen pairs, forming the largest part of the thoracic skeleton.Miller 2020, p. 292
  • Each rib is a bony part, the os costale, and a ventral cartilaginous part, the costal cartilage.Miller 2020, p. 292
  • The first nine reach the sternum and are the sternal, or true, ribs.Miller 2020, p. 292
  • The last four do not, and are the asternal, or false, ribs.Miller 2020, p. 292
  • The cartilages of the tenth, eleventh and twelfth join the cartilage of the ninth to make the costal arch on each side.Miller 2020, p. 292
  • The cartilages of the thirteenth pair end free in the muscle of the flank, which is why those are called floating ribs.Miller 2020, p. 292
  • The ninth is the longest, and has the longest cartilage; the ribs shorten in both directions away from it, in bone and in cartilage alike.Miller 2020, p. 292
  • The costochondral junctions of the third to the eighth lie nearly in one horizontal plane.Miller 2020, p. 292
  • Because the sternum and the vertebral column diverge behind the thoracic inlet and each rib arches further out than the one before, the back of the chest is far roomier than the front.Miller 2020, p. 292
  • The intercostal spaces are two or three times as wide as the ribs beside them.Miller 2020, p. 292
  • The seventh is the one the book describes as the typical rib.Miller 2020, p. 293

Named parts

What a member of this set carries, and what each part is called in the Nomina Anatomica Veterinaria.

Head of the ribCaput costae
The end that meets the bodies of two neighbouring vertebrae.Miller 2020, p. 294
Neck of the ribCollum costae
The narrowing beyond the head.Miller 2020, p. 294
Tubercle of the ribTuberculum costae
The knob beyond the neck, which meets the transverse process of its own vertebra.Miller 2020, p. 294
Body of the ribCorpus costae
The shaft between the vertebral and the sternal end.Miller 2020, p. 294
Angle of the ribAngulus costae
Where the shaft turns to run down the chest wall.Miller 2020, p. 294
Costal grooveSulcus costae
The channel inside the caudal border carrying the intercostal vessels and nerve.Miller 2020, p. 294

The members

In order along the set. Any one of them can be singled out in the model above, with the picker beneath it. The ones that are taught by name have a page of their own.

  • Rib 1Costa IArticulates with T1 (and C7) and the manubrium; thoracic inletOwn page
  • Rib 2Costa II
  • Rib 3Costa III
  • Rib 4Costa IV
  • Rib 5Costa V
  • Rib 6Costa VI
  • Rib 7Costa VII
  • Rib 8Costa VIII
  • Rib 9Costa IX
  • Rib 10Costa X
  • Rib 11Costa XI
  • Rib 12Costa XII
  • Rib 13Costa XIIIArticulates with T13; cartilage ends free in the flank musculatureOwn page

References

Where to read this set in full, and where everything above was read.

  • Miller 2020Miller 2020, ch. 4 The Skeleton, Ribs, PDF p. 292
  • König & Liebich 2020skeleton of the thorax, p. 125
  • Dyce 2017ch. 13 Thorax of the Dog and Cat, p. 403
  • NAV 2017Osteologia