What is humerus?
Humerus is the first and largest long bone of the frontal or upper limb. This bone connects to the body at the shoulder joint and articulates distally with radius and ulna at the elbow joint. The evolutionary adaptation that helps in the locomotion is present in most of the wide range of animals classified as tetraody or four -digit animals. This group includes reptiles, amphibians, birds and mammals. The upper arm of the bone provides points of connection and support of the muscles of the chest, upper back, shoulders and arms. In cooperation with these muscles, it allows the movement of the arm along several movement planes, which makes it one of the most moving bones in the human body.
For the first time in the early Devonian period, about 400 million years ago, humerus with the initial appearance between tetraples like fish tetrapody. These early forelegs were too club and clumsy to be used to walk, and are most likely employed when navigating underwater and currents. Over time, these toughs wereGreat pendants are replaced by robust, fully created limbs that would allow early tetraons to travel between reduced water formations during the dry season.
Most of the modern versions of the humerus have been somewhat prolonged, but otherwise little has changed since the first form. Structurally, the humerus consists of a long, cylindrical center called the diaphysis , with enlarged ends known as epiphysis . The epiphysis, which fits into the joint joint on the shoulder, has the shape of the ball and is generally called a humeral head . The lower epiphysis, known as condyle , has different structures that make the movement of the articulated bones and tendons of forearms easier.
In children and adolescents, there is a zone of rapid cell division between the diffusion and the epiphysis known as the epiphysis board or the growth plate. It is an area of rapid cell division, where the bone is prolonged during the growth period. GrowthThe plate is susceptible to trauma and is a common place of fractures in children. Once the growth is completed, this zone ceases to accelerate the cell division and is called the epipheseal line .
Humerus is similar to another long bone in composition and structure. The outer surface is rough and irregular and contains more epicondyles, processes and fossae to facilitate muscles and tendons. Like other bones, it has an outer and inner layer of connective tissue. The outer layer, known as periosteum , contains fibroblasts and nerve endings, which is very sensitive to injury or manipulation. This layer of connective tissue is responsible for generating new cells during bone growth or healing.
under periosteem lies endosteum . The endosteum is a hard, fibrous membrane that surrounds the bone tissue itself. In the bone, mushroom tissue is impregnated with bone marrow, where bones, lymph and blood cells are produced. The network of linked channels passes through bones and acts as channels for blood vessels NesoShe feels oxygen and nutrients.
upper arm fractures are classified as proximal, medium or distal. Proximal fractures occur in the shoulder joint or close and may include rotator cuff muscles. Middle shaft fractures usually occur along a long part of the bone and will most likely include a radial nerve that operates a large part of the arm itself. Distal fractures take place near the shoulder joint and are rare among adults. Humeral fractures are often treated with a slingshot or orthosis, and all except the most serious will usually be well recovered by flaws.