Anatomy: The muscles on the back of the upper arm (brachium) comprise the 3-headed arm stretcher (M triceps brachii). The muscle primarily stretches the elbow joint (and the shoulder joint). 1  Clavicula.  Bursa subcutanea acromialis.
Overview. The cervical spine is made up of 7 vertebrae. The first 2, C1 and C2, are highly specialized and are given unique names: atlas and axis, respectively. C3-C7 are more classic vertebrae, having a body, pedicles, laminae, spinous processes, and facet joints.
The vertebral column is composed of a series of 31 separate bones known as vertebrae. There are seven cervical or neck vertebrae, 12 thoracic vertebrae, and five lumbar vertebrae. The sacrum is composed of five fused vertebrae, and there are two coccygeal vertebrae which are sometimes fused (fig.1). In the normal adult there are four curvatures in the vertebral column in an anteroposterior plane. These serve to align the head with a vertical line through the pelvis (fig. 2).he arch encloses an opening, the vertebral foramen, which helps to form a canal in which the spinal cord is housed. Protruding from the posterior extreme of each neural arch is a spinous process and extending from the lateral edges of each arch are transverse processes.