Connective tissues of the hand and foot.

In this paper we are submitting studies on the onto- and phylogenetic development of the superficial muscular and fascial layers of the hand and forearm of mammals. The object of this study was to investigate the following items: the ontogenetic development of the m. flexor digitorum superficialis, of the m. flexor digitorum profundus, of the m. palmaris longus, of the palmaris brevis of the human hand, the nerve supply of these muscles, the development of palmar and plantar aponeurosis and of other fasciae related to the palmar and plantar aponeuroses. We compared conclusions drawn from the studies on the ontogenetic development with observations gained from the phylogenetic development of the structures of the human hand and forearm and applied our findings to various species of mammals. The results of these comparisons are expressed in this study presenting interpretations of the phylogenetic development of superficial muscular and fascial layers of the mammalian hand and foot. Furthermore we ascertained the homology of the superficial muscular and fascial layer of the mammalian autopodion, we reviewed one of the theories on the origin of Dupuytren's contracture and commented on opinions of the developmental origin of certain muscular varieties present in the human hand and forearm. Apart from this we established certain basic data on the development of the fasciae of the human hand and foot. Our findings on the variability of the palmar aponeurotic attachments of the human hand were confronted with the incidence and frequency of one particular finger when affected by a Dupuytren's contracture and we commented on the predisposition of certain fingers or toes for the affliction of this impairment. We conducted 152 series of histological sections through the hand and feet of embryos and foetuses sized 12-100 mm in c.-r. length, as well as 84 series of histological transverse sections through human embryonal hands in order to study the ontogenetic development of superficial muscular and fascial layers of the human hand, forearm and foot. The embryonal extremities were cut transversally, parallel to the palm and several sagittal sections were carried out for control purposes. The phylogenetic development of the superficial muscular and fascial layers of the hand was investigated by specimens processed under a micro-dissecting microscope. 55 specimens of various extremities were thus prepared, obtained from 22 species of mammals. Many animals were selected in order to cover species of mammals significant for their evolution.(ABSTRACT TRUNCATED AT 400 WORDS)