The Skeleton: Thorax (25 bones)
False ribs (8-12)
False ribs Location: • Thoracic wall Description: • Ribs 8-12 • Paired, curved, flat bones • Articulate with thoracic vertebrae • Attach indirectly to sternum via a shared costal cartilage (ribs 8-10) or not attached to sternum (ribs 11-12) Comment: • True ribs (ribs 1-7): attach directly to sternum by costal cartilages • False ribs (ribs 8-12): attach indirectly to sternum via a shared costal cartilage (ribs 8-10); ribs 11-12 are not associated with costal cartilages and thus not attached to sternum (they are also called "floating ribs")
Sternum (1 bone)
Location: • Thorax (anterior midline) Description: • Flat bone with three parts: manubrium, body, and xiphoid process • Characteristic features include jugular notch and sternal angle (angle of Louis) • Articulates with upper seven costal cartilages and clavicles Also known as: • "Breastbone" Comment: • Provides for attachment of sternocleidomastoid, pectoralis major, sternohyoid, and sternothyroid muscles
Floating ribs (11-12)
Location: Thoracic wall Description: • Ribs 11-12 • Paired, curved, flat bones • Articulate with thoracic vertebrae • Not associated with costal cartilage, thus not attached to sternum Comment: • True ribs (ribs 1-7): attach directly to sternum by costal cartilages • False ribs (ribs 8-12): attach indirectly to sternum via a shared costal cartilage (ribs 8-10); ribs 11-12 are not associated with costal cartilages and thus not attached to sternum (they are also called "floating ribs")
Ribs (24 bones)
Location: Thoracic wall Description: • Twelve pairs of curved, flat bones • All ribs: articulate with thoracic vertebrae • With their costal cartilages, true ribs (ribs 1-7) form continuous arch between vertebrae and sternum • True ribs (ribs 1-7): attached directly to sternum by costal cartilages • False ribs (ribs 8-12): attach indirectly to sternum via a shared costal cartilage (ribs 8-10); ribs 11-12 are not associated with costal cartilages and thus not attached to sternum (they are also called "floating ribs")
Ribs (24 bones)
Location: Thoracic wall Description: • 12 pairs of curved, flat bones • All ribs: articulate with thoracic vertebrae • With their costal cartilages, true ribs (ribs 1-7) form continuous arch between vertebrae and sternum • True ribs (ribs 1-7): attached directly to sternum by costal cartilages • False ribs (ribs 8-12): attach indirectly to sternum via a shared costal cartilage (ribs 8-10); ribs 11-12 are not associated with costal cartilages and thus not attached to sternum (they are also called "floating ribs"
Thorax (25 bones)
Superior trunk comments: - Sternum (1) - Ribs (24) - True ribs - false ribs - floating ribs
True ribs (1-7)
True ribs Location: • Thoracic wall Description: • Ribs 1-7 • Paired, curved, flat bones • Articulate with thoracic vertebrae • Attach directly to sternum by costal cartilages Comment: • With their costal cartilages, true ribs form continuous arch between vertebrae and sternum • False ribs (ribs 8-12): attached indirectly to sternum via a shared costal cartilage (8-10) or not attached to sternum (11-12) • Floating ribs (11-12): not associated with costal cartilages and, thus, not attached to sternum
