ABSTRACT
[Objective]The skin is the biggest organ in the body. The human epidermis functions as a defence against various antigens in addition to physical and bio-chemical protection. The dermis consists of dense connective tissue which contains the circulatory system and sensory nerve endings. In this paper, regional differences in the structures of human skin are described.<BR>[Materials and Methods]The skin of different regions in the human body was examined by optical and electron microscopy and by utilizing various morphological techniques. <BR>[Results and Discussion]Epidermis:The cornified layer in the finger pulp and heel, which receives strong mechanical stimuli, is considerably thicker than other regions. The germinal layer consisting of spinous and basal layers becomes thinner with aging. Langerhans cells that produce antigens are scattered in the germinal layer. Furthermore, Merkel cells situated at the basal layer are found in the finger pulp, bottom of the foot and the hair disks of limbs. These cells are involved in the sense of touch or pressure. Dermis:The dermis is divided into the papillary and reticular layers, which consist of loose and dense connective tissue, respectively. In the papillary layer, fibrocytes and mast cells are distributed. Large-sized dermal papillae are found the in finger pulp and bottom of the foot, but there are also a few small papillae in other regions. In large papillae, loops of blood capillaries and Meissner's tactile corpuscles were observed. In addition, large-sized lymphatic capillaries are present in the papillary layer.A dense network of free endings, which are situated beneath the epidermis and are responsible for thermal nociception, are abundant in the face, palm, forearm and sacrum. Corpuscles of Vater-Pacini situated in the deep dermis or subcutaneous tissue are found in the finger pulp, and bottom of the foot. <BR>[Conclusion]In conclusion, it is likely that acupuncture and moxibustion may directly or indirectly stimulate Langerhans cells, Merkel cells, fibrocytes, mast cells or various nerve endings.
ABSTRACT
The effect of concanavalin A (Con A) on nerve regeneration in heterograft was done in the present study. A segment about 5mm long was removed from the right sciatic nerve of adult rats. A 8mm of the heterograft nerve segment from the tibial nerve of the rabbit and pretreated by Con A was transplanted into the gap of the severed rat nerve. Regenerating nerve fibers were found from the proximal part of the sciatic nerve into the graft, and also from the graft into the distal part of the sciatic nerve at the 4th,8th and 12th week after transplantation. Regenerating nerve fibers existed separately or clustered into fascicles in the graft,as well as in the distal part of sciatic nerve. Some unmyeli-nated nerve fibers were scattered among the regenerating myelinated fibers. The gastrocnemius muscle was AChE-positive at 8th and 12th week after transplantation. In silver-combined AChE staining section, the regenerating nerve fibers could be seen connecting with the motor endplates. There were regenerating free nerve endings and nerve fascicles in the dermis and epidermis at 8th and 12th week after transplantation. The present study showed that the pretreatment of Con A had benefit to that the regenerating nerve fibers to pass through the heterograft and reinnervated to the targetes.ADepartment of Anatomy,Jiangxi Medical College,Nanchang 330006,China
ABSTRACT
An observation of nerve terminals in the induced glioblastoma of mouse was made by Nonidez and Glees impregnation method.In the marginal zones of the glioblastoma innoculated in the brain or muscle,nerve fascicles of various sizes with or without the blood vessels could be seen. In some case the nerve fibers formed a perivascular plexus through the perivascular space and some nerve fibers terminated on vascular walls.The nerve fibers within the tumor seemed to be related to those nerve fibers distributed in the brain tissue near the tumor or in the subcutaneous tissues, hair follicules of muscles around the tumor, hence, we suggest that the nerves whthin the tumor were growing in from the surrounding normal tissues.The amount of the nerve fibers was more abundant in the periphery than in the center of the tumor, the nerve fibers ran through the stroma or parenchyma of the tumor and gave out many branches to the tumor cells, we have also observed various types of nerve terminals for example: bulbar, isolated bifurcated, fusiform,circular, branched, brush-formed and club-formed endings.According to the findings mentioned above, it is concluded that the induced glioblastoma of mouse is innervated by nerve endings.