Neural and vascular development in the human phallus was studied with the light and electron microscopes. Eight specimens were examined ranging in gestational age from 7 to 15 wk. In the 7 week phallus the corpora cavernosa penis was represented by masses of vascular mesenchyme. By the 15th week, vascularity of these masses had increased but was still limited to capillaries. Other changes evident in the corpora cavernosa penis from the 7th to the 15th wk were: peripheral cells differentiad into the tunica albuginea; and the central cells began to organize into trabeculae. Dorsal vascular structures were present in all specimens. These vessels differentiated from capillaries in the earliest specimens to paired dorsal arteries and deep dorsal vein in the 13th and 15th wk phallus. Nerves were present in the phallus as early as the 7th wk of development. Nerves within the blastemata of the corpora cavernosa penis were not seen at all ages examined. In the 7 wk phallus a few Schwann cells surround a large number of naked axons of varying diameters. Schwann cell processes did not penetrate deep within the axons in the majority of nerves. A mesenchymal component, the future perineurium, was lacking at 7 wk. Growth and branching of Schwann cell processes in older specimens divide the axons into smaller groups. Schwann cell nuclei frequently appeared within the larger axon bundles. Perineurial cells increased from 1 to several layers from the 10th to the 15th wk. Development of the nerves of the human phallus from the 7th to the 15th wk appeared to correspond to Cravioto's second and third stages described in the human limb.
|Original language||English (US)|
|Number of pages||12|
|State||Published - Dec 1 1974|
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