The lateral branch also supplies the second lumbrical. Variation
The naturally occurring anomalies of the median nerve are:

Bifurcation of the median nerve typically occurs after the nerve exits the carpal tunnel; however, in a small percentage (5-10%) of individuals, the median nerve bifurcates more proximal in the carpal tunnel, wrist, or forearm. During gestation, a median artery that serves the hand retracts. However, in some individuals, the median artery does not retract and follows the course next to the median nerve into the hand. Martin-Gruber anastomoses can occur when branches of the median nerve cross-over in the forearm and merge with the ulnar nerve to innervate portions of the forehand. Riche-Cannieu anastomosis can occur when a connection exists between recurrent branch of the median nerve and deep branch of the ulnar nerve of the hand. Function
The median nerve is the main nerve of the front of the forearm. It supplies the muscles of the front of the forearm and muscles of the thenar eminence, thus controlling the coarse movements of the hand. Therefore, it is also called "labourers nerve". Arm
The median nerve has no voluntary motor or cutaneous function in the brachium. It gives vascular branches to the wall of the brachial artery. These vascular branches carry sympathetic fibers. Forearm
It innervates all of the flexors in the forearm, except flexor carpi ulnaris and that part of flexor digitorum profundus that supplies the fourth and fifth digits. The latter two muscles are supplied by the ulnar nerve (specifically the muscular branches of ulnar nerve).
In cases of suspicion of SM help can also be drawn from analysis of mutation in KIT(D816V) in peripheral blood using sensitive PCR-technologyTo set the diagnosis of systemic mastocytosis, certain criteria must be met. Either one major + one minor criterium or 3 minor criteria has to be fulfilled:

Major criterion
Dense infiltrates of >15 mast cells in the bone marrow or an extracutaneous organ

Minor criteria
Aberrant phenotype on the mast cells (pos. for CD2 and/or CD25)
Aberrant mast cell morphology (spindle-shaped)
Finding of mutation in KIT(D816V)
S-tryptase >20 ng/ml

Other mast cell diseases
Other types of mast cell disease include:

Monoclonal mast cell activation, defined by the World Health Organization definitions 2010, also has increased mast cells but insufficient to be systemic mastocytosis (in World Health Organization Definitions)
Mast cell activation syndrome – has normal number of mast cells, but all the symptoms and in some cases the genetic markers of systemic mastocytosis
Another known but rare mast cell proliferation disease is mast cell sarcoma. Classification
Mastocytosis can occur in a variety of forms:

Cutaneous mastocytosis (CM)
The most common cutaneous mastocytosis is maculopapular cutaneous mastocytosis, previously named papular urticaria pigmentosa (UP), more common in children, although also seen in adults. Telangiectasia macularis eruptiva perstans (TMEP) is a much rarer form of cutaneous mastocytosis that affects adults. [2] MPCM and TMEP can be a part of indolent systemic mastocytosis.