Apical cytoplasm

About: Apical cytoplasm is a research topic. Over the lifetime, 1080 publications have been published within this topic receiving 36131 citations.

Ultrastructure of epithelial cells in the epididymal region of the turkey (Meleagris gallopavo).

Abstract: SUMMARY The epithelial cells in the epididymal region of the turkey were classified ultra­structurally by electron microscopy Six cell types were described: squamous and low cuboidal cells of the rete testis, non-ciliated Type I and ciliated cells of the ductuli efferentes and connecting ductules, non-ciliated Type II cells of the ductus epididymidis, and basal cells occasionally found in all the ducts except the rete The squamous cells were more electron-dense and contained fewer organelles than the cuboidal cells The Type I cells secreted blebs of material into the ductal lumen and contained numerous mitochondria, extensive rough and smooth endo­plasmic reticulum and well developed Golgi complexes, indicating active apocrine secretion The Type I cells also contained large zymogen-like granules and numerous rod-shaped bodies which were considered to be lysosomes associated with an absorptive function The Type II cells had small Golgi complexes and numerous lipid vesicles Ciliated cells presumably concerned in the transport of spermatozoa contained numerous mitochondria in the apical cytoplasm, lobulated nuclei and perinuclear fibrillar bundles Lysosomal-like bodies and large cytoplasmic vacuoles indicated an absorptive function The basal cells were smaller and more electron­dense than other cell types, and rested directly on the basal lamina This study has shown that the epithelial cells of the ductuli efferentes appear to be the most active cells of the turkey epididymal region They apparently function in the transportation of spermatozoa, resorption of luminal fluids, and the secretion of proteinaceous material

Uptake of colloidal particles by cells of the caput epididymidis.

Abstract: Colloidal mercuric sulfide injected into the rete testis adhered to the stereocilia of the epithelial cells and subsequently moved into a highly developed canalicular system in the apical cytoplasm. The canalicular invaginations of the cell surface arising between the stereocilia lead to cytoplasmic vacuoles that concentrate the particulate matter. The limiting membrane of the stereocilia and of the canaliculi and vacuoles is covered by a layer of amorphous material. It is speculated that this may bind particles, molecules, and ions as does an ion exchange resin, and that it may, in this way, act as a carrier in the uptake and transport of substances by cells.

The fine structure of the guinea pig visceral yolk sac placenta

Abstract: The structure of the guinea pig visceral yolk sac from 26 days of gestation to term was studied by transmission and scanning electron microscopy. Particular emphasis was placed on the columnar endoderm cells of the villous portion of the yolk sac. The apical cytoplasm of the endoderm cells contained numerous membrane invaginations, endocytic vesicles, dense tubules and large vacuoles which appeared to form an interrelated absorptive system. The saccular invaginations of the apical cell membrane were specialized by the development of both an amorphous extracellular coat and an internal coat. Both the endocytic vesicles and dense tubules were thought to be derived from the saccular invaginations following detachment of the latter from the cell surface — the endocytic vesicles forming by fusion of saccules creating progressively larger structures, and the dense apical tubules forming by a process involving fluid loss from the saccules. Large vacuoles were present deeper in the apical cytoplasm; these probably were formed by fusion of smaller vesicles. The supranuclear cytoplasm contained numerous dense droplets and a Golgi zone. The possible relationships of the droplets to the vacuoles was discussed.