Surgical neck of the humerus the skin over a small part of the lateral shoulder. 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
Effect of spaceflight on the human body on the bones, there is a rapid increase in bone loss, from 3% cortical bone loss per decade to about 1% every month the body is exposed to microgravity, for an otherwise healthy adult. The rapid change in bone density is dramatic, making bones frail and resulting in symptoms which resemble those of osteoporosis. On Earth, the bones are constantly being shed and regenerated through a well-balanced system which involves signaling of osteoblasts and osteoclasts. These systems are coupled, so that whenever bone is broken down, newly formed layers take its place—neither should happen without the other, in a healthy