Upper Back - Osteology

Question 1

Name important bones of the basilar skull.

Answer 1

• temporal bone - occipital bone

Question 2

Name how many vertebrae make up each portion of the spine.

Answer 2

• cervical: 7 - thoracic: 12 - lumbar: 5 - sacrum: 5 (fused) - coccyx: 4 (union)

Question 3

Identify features of a typical vertebrae.

Answer 3

Question 4

Name unique features of cervical vertebrae.

Answer 4

• “bi-fid” spinous processes
• large triangular vertebral foramen
• anterior and posterior tubercles on tranverse processes
• uncinate processes
• transverse foramen
• costotransverse bar

Question 5

Name unique features about C1 (atlas).

Answer 5

• supports the skull
• widest of the cervical vertebrae
• no body/no spine
• contains anterior and posterior arches (with tubercles)
• contains lateral masses
• superior articulation: occipital condyles of the skull = atlantooccipital joints
• inferior articulation: axis = atlantoaxial joints

Question 6

Name unique features about C2.

Answer 6

• smallest transverse process
• characterized by the dens (odontoid process)
• dens articulates with the anterior arch of atlas forming a pivto around which atlas rotates
• supported by cruciform, apical, alar ligaments, and tectorial membrane

Question 7

Name unique features about C7.

Answer 7

• also called the vertebra prominens due to long spinous process
• nearly horizontal
• ends in single tubercle (not bi-fid)
• forms a visible protrusion
• provides attachment site for ligamentum nuchae, supraspinus ligaments, numerous back muscles

Question 8

Name unique features about thoracic vertebrae.

Answer 8

• small round vertebral foramen
• “heart-shaped” vertebral body
• well-pronounced lamina
• transverse costal facets
• strongly inferiorly-directed spinous process
• superior and inferior costal facets (to articulate with ribs)

Question 9

Name unique features about lumbar vertebrae.

Answer 9

• large, oval-shaped vertebral foramen
• long, slender transverse process
• large, “kidney-shaped” vertebral body
• mamillary process
• accessory process
• short sturdy “hatchet-shaped” spinous process

* L5 = largest body of the vertebrae

Question 10

Name unique features about the sacrum.

Answer 10

• sacral tuberosity
• posterior sacral foramina
• sacral cornua
• sacral hiatus
• medial sacral crest
• lateral sacral crest
• median sacral crest
• superior articulating process
• sacral promontory
• sacral ala
• transverse lines
• sacral apex
• anterior sacral foramina
• vertebral body of S1
• auricular surface of sacrum

Question 11

Describe the vertebral homologues of the sacrum.

Answer 11

• median sacral crest: fused spinous processes
• medial sacral crest: fused articulating processes
• lateral sacral crest: fused transverse processes

Question 12

Name unique features of the coccyx.

Answer 12

• wedge-shaped bone formed by union of the four coccygeal vertebrae
• provides attachment for the coccygeus and levator ani muscles