AbstractOur study was performed by dissection on a number of 54 nervous trunks of the median nerve of the fetus. We found that the median nerve is always formed from two roots, their joining being at different levels of the upper limb, between the axilla and the elbow. The axilla nerve trunk was formed at the level of the axillary region, in 38.89% of the cases, in 22.22% of the cases the union was made at the middle part of the arm, and in 38.89% of the cases in the elbow. The lateral root of the medial nerve was formed in 55.56% of cases from a single nerve fascicle, in 44.44% of cases consisting of two nerve fascicles. The medial root was formed in 61.11% of cases from a single nerve fascicle, in 38.89% of the cases being made up of two nerve fascicles. In 27.78% of cases, the medial root passed behind the axillary artery. Regarding the volume of the two roots, we found that in 44.44% of the cases, the lateral root was more voluminous, in 27.78% of cases, the median root was larger and in 27.78% of cases, the two roots were approximately equal. We have encountered situations where a ramification for the forearms muscles emerged from the lateral root. Occasionally, a ram for the brachial muscle was detached from the medial root, and from the lateral root a ram for the biceps muscle, both muscles receiving branches also from the musculocutaneous nerve. We have encountered a single case where the median nerve inches the anterior muscles of the arm, missing the musculocutaneous nerve. In cases of low joining of the roots, we have encountered cases where a lateral root formed a ram for forearm muscles. The anastomoses between the two median nerve roots can sometimes be located just above their union or anterior to the lower portion of the axillary artery. In one case, we encountered between the two roots, above their union, the existence of three oblique anastomoses, the two upper ones from the lateral to the medial root, and the third from the medial root to the lateral root. Common are anastomoses between the roots of the roots and the root on the opposite side. The most common are the anastomosis between the medial fascicle of the lateral root and the medial root of the median nerve. In one case, we encountered a double overlap between the musculocutaneous nerve and the lateral nerve root. In one case, we encountered a strong anastomosis between the medial nerve fascicle of the medial root and the radial nerve. Common and at all levels of the upper limb are the anastomoses between the median and ulnar nerves. In the case of a low union of the two median roots, we encountered anastomoses between a root of the root and the ulnar nerve, or between a root and the ulnar nerve. I encountered a single case with an anastomosis, Martin- Gruber, which was previously passing through the ulnar and interos-like arteries and from which the anterior forearm muscles were detached.
Formation, trajectory and distribution variants of the median nerve of the fetus
