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.
A macromolecule that elicits an immune response by binding to receptors of B cells or T cells. antigen presentation. The process by which an MHC molecule binds to a fragment of an intracellular protein antigen and carries it to the cell surface, where it is displayed and can be recognized by a T cell.