Introduction. A broken arm or wrist is usually caused by a fall onto an outstretched arm. It typically takes about six to eight weeks to heal in adults, and less time in children. Doctors refer to all breaks or cracks in bones as fractures.Go to your nearest accident and emergency (A&E) department if you think you or your child has broken a bone.t typically takes about six to eight weeks to heal in adults, and less time in children. Doctors refer to all breaks or cracks in bones as fractures. Go to your nearest accident and emergency (A&E) department if you think you or your child has broken a bone.
In contrast, the overwhelming majority of antigens for T cells are proteins, and these must be fragmented and recognized in association with MHC products expressed on the surface of nucleated cells, not in soluble form.
Antibodies recognize specific antigens by identifying certain areas on the surface of the antigen known as antigenic determinants. Once the specific antigenic determinant is recognized, the antibody will bind to the determinant.The antigen is tagged as an intruder and labeled for destruction by other immune cells.Antibodies protect against substances prior to cell infection. Antibodies are produced by a type of white blood cell called a B cell (B lymphocyte).B cells develop from stem cells in bone marrow. When B cells become activated due to the presence of a particular antigen, they develop into cells called plasma cells.ntibodies recognize specific antigens by identifying certain areas on the surface of the antigen known as antigenic determinants. Once the specific antigenic determinant is recognized, the antibody will bind to the determinant.