Sacrum, Coccyx, Thorax, and Sternum

Sacral Promentary

Where the first sacral vertebrae bulges into pelvic cavity

Sacral Foramina

Ventral Foramina - passage for ventral rami of sacral spinal nerves

Dorsal Foramina - passage for dorsal rami of sacral spinal nerves

Fusion of Sacral Vertebrae Characteristics

Happens age 16-30 years old, transverse lines mark fusion, superior surface articulates with L5, inferiorly articulates with coccyx

Coccyx

Triangular bone from fusion of 3-5 vertebral bones - from 20-30 years of age, only slight support to pelvic organs

Thorax

Entire chest, thoracic cage

Thoracic Cage

Formed by sternum, ribs, and costal cartilages, bodies of thoracic vertebrae

Sternum Characteristics

Flattened bone - 6 inches long, made of 3 parts (manubrium, body, and xiphoid process), articulates with the costal cartilage of ribs (except xiphoid)

Ribs (how many pairs and their function)

12 pairs - structural support

Ribs 1-7 function (and which vertebrae do they attach to)

Direct attachment to sternum, called “true” or “vertebrosternal” ribs, thoracic

Ribs 8-10 Function

Indirect attachment to sternum, called “false” ribs or “vertebrochondral” ribs

Ribs 11-12 Function

No attachment to sternum, called “floating” ribs

Parts of Ribs

Head, neck, shaft, facet, costal angle, costal groove, junction w/ costal cartilage, articular facet on tubercle

What is Costal Cartilage

hyaline cartilage that connects ribs to sternum