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.
T-cells contain proteins called T-cell receptors that populate the T-cell membrane. They are capable of recognizing various types of antigens (substances that provoke an immune response). T-lymphocytes are derived from the thymus and travel to the spleen via blood vessels.B-lymphocytes or B-cells originate from bone marrow stem cells.hey are capable of recognizing various types of antigens (substances that provoke an immune response). T-lymphocytes are derived from the thymus and travel to the spleen via blood vessels. B-lymphocytes or B-cells originate from bone marrow stem cells.