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.
- Also cause certain reactions against transplanted tissue. - 1000s of different B cells, each recognizes a different antigen on the surface of a macrophage. - Each antigen stimulates production of a single specific antibody B cells (along with T cells) come in contact with antigen. - They are stimulated (by T cells) to produce many clones, plasma cells, which make antibodies.