Ultrastructure of adrenal medullary cells in the goose and duck
Guzsal, E.; Hassan, A.
Acta Veterinaria Academiae Scientiarum Hungaricae 25(4): 321-333
1975
ISSN/ISBN: 0001-7205 PMID: 1233876 Document Number: 85290
Four types of chromaffin cells were found. The adrenaline-containing cells were 50-200 nm in diameter, mostly spherical in shape, and showed various degrees of electron density. The noradrenaline-containing cells had vesiculated cytoplasm; the vesicles, 150-500 nm in diameter, were spherical or ellipsoid, and comprised various amounts of a diversely arranged dense substance. The so-called dark cells, characterized by the presence of tightly-arranged, large, highly electron-dense cytoplasmic granules of heterogeneous shapes, might be regarded as a functional variant of the noradrenaline-containing cell. The fourth chromaffin cell type was represented by a transitory form (sympathicoblast), equipped with processes. Small, multipolar nerve cells were also found in the medullary tissue. In chromaffin cells two types of large vacuoles are described. These cells form cholinergic synapses with the preganglional sympathetic fibres. Some of the unmyelinated fibres were identified as adrenergic. The chromaffin cells are surrounded by somatic satellite cells. The cell elements are connected with one another by demosomes. The interstitium contains fibroblasts, collagen fibres, Schwann cells, unmyelinated nerve fibres and sinuses lined with fenestrated endothelium. The ultrastructure of the adrenal medulla does not notably differ either between male and female birds, or between the sexually active and inactive periods.