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 5 sections of the spine: 1  The cervical spine makes up the neck and has 7 vertibrae. 2  The thoracic spine has 12 vertibrae which the ribs attach to. 3  The lumbar spine has 5 which make the lower back.  The sacrum consists of 5 bones which are fused or stuck together and the coccyx is made up of 4 tiny bones and used to be a tail.