Supplementary Observations on the Histology of the Sympathetic Trunk Ganglia in Human Adults

Abstract

The nerve cells in adult human sympathetic superior cervical and lumbar ganglia may be classified into the large, the intermediate and the small in size, but a small number of giant cells are also present.The cell nucleus in such a nerve cell usually takes eccentric, and very often a marginal position in the cell body. The size of the nucleus increases in a slow arithmetical progression as the diameter of the cell body increases.Granules of yellow and black pigments are frequently found in the nerve cells. Black pigments are found preferentially in the small cells. In such cells the fibrils are found sorely degenerated. Such cells are probably devoid of any mentionable functional meaning, as little as the apolar cells mentioned below.The nerve cells in the sympathetic trunk ganglia are always capsulated and are characterized by their multipolarity. The development of their nerve processes is markedly good in the large and the intermediate cells, but in the small cells it is very poor, some apolar cells being not lacking.These nerve cells are classifiable into the Type I and Type II, a small number of mixed type cells being also observable. DOGIEL and ABRAHAM have asserted the afferent nature of the Type II cells, but I cannot see any justification for such an assertion.According to the situation of the nucleus, Type I cells may be divided into 3 forms of cells with a centrally standing nucleus, an eccentrically standing nucleus and a marginally or polarly standing nucleus. In the first form, the plasmodium around a cell is about equally thick on all sides and the nuclei therein are arranged in a single loose row, the short processes emerging indifferently from all sides of the surface of the mother cell. In the nerve cell with a eccentrically or marginally placed nucleus, the short processes usually come out one-sidedly from the cell surface farthest from the nucleus. The plasmodium around such a cell is much better developed near the process pole than on the side of the nucleus pole. The Type I cells in the trunk ganglia belong in overwhelming majority to the latter two forms.The Type I cells may be subdivided again according to the varied running courses of the short processes and their terminal modes as follows: 1. The cells of which the short processes show one or more anastomosis. 2. Fenestrated cells. 3. Cells with processes ending in one or more knobs or clubs. 4. Cells with short processes ending in end lamellae. 5. Those with processes ending in one or more end rings (only rarely found in trunk ganglia). There are also many nerve cells having more than one kinds of end-bodies on their short processes.The cells with polarly standing nuclei may be divided into octopus type cells and jelly fish type cells by the course forms of the short processes running out from the cell surface opposite to the nucleus pole. These are found in particular abundance in the superior cervical ganglion. Some of these cells may be distinguished as spiral type cells, where the short processes spirally surround the long processes. In some cases, a pair of octopus or jelly-fish type cells are placed side by side with their process poles facing each other and their nerve processes are seen mutually entwining. These may be called entwining cells.Among the Type I cells with centrally standing nuclei, we find on rare occasions special types that may be called glomerular type cells. The short processes of such a cell end in the plasmodium surrounding the mother cell in the form of a glomerulus.The cells of Type II generally take a round or an oblong form, their nucleus is centrally standing and the plasmodium is arranged in an approximately equal width around the cell body. The nerve processes of the round cell come out indifferently from all sides of the cell body but of the oblong cell they emerge from the two poles.