Surgical neck of the humerus Surgical neck of the humerus The surgical neck of the humerus is a constriction below the tubercles of the greater tubercle and lesser tubercle, and above the Deltoid Tuberosity. It is much more frequently fractured than the anatomical neck of the humerus. A fracture in this area is most likely to cause damage to the axillary nerve and posterior circumflex humeral artery. Damage to the axillary nerve affects function of the teres minor and deltoid muscles, resulting in loss of abduction of arm (from 15-90 degrees), weak flexion, extension, and rotation of shoulder as well as loss of sensation of
Composition of the human body Not all elements which are found in the human body in trace quantities play a role in life. Some of these elements are thought to be simple bystander contaminants without function (examples: caesium, titanium), while many others are thought to be active toxics, depending on amount (cadmium, mercury, radioactives). The possible utility and toxicity of a few elements at levels normally found in the body (aluminium) is debated. Functions have been proposed for trace amounts of cadmium and lead, although these are almost certainly toxic in amounts very much larger than normally found in the body. There is evidence that