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 human back consists of the lumbar spine (or lower back) and the thoracic spine (or upper back). The back is a complex structure made up of the following parts: 1  Bones: Spinal bones are also known as vertebrae. 2  Discs: the cartilage-like pads that act as cushions between the spinal segments.