scholarly journals The Fine Structure of the Parathyroid Gland

1958 ◽  
Vol 4 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Jerry Steven Trier
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Connective Tissue ◽  
Light Microscope ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Perivascular Spaces ◽  
Chief Cells ◽  
Golgi Bodies ◽  
Endocrine Tissues

The fine structure of the parathyroid of the macaque is described, and is correlated with classical parathyroid cytology as seen in the light microscope. The two parenchymal cell types, the chief cells and the oxyphil cells, have been recognized in electron micrographs. The chief cells contain within their cytoplasm mitochondria, endoplasmic reticulum, and Golgi bodies similar to those found in other endocrine tissues as well as frequent PAS-positive granules. The juxtanuclear body of the light microscopists is identified with stacks of parallel lamellar elements of the endoplasmic reticulum of the ergastoplasmic or granular type. Oxyphil cells are characterized by juxtanuclear bodies and by numerous mitochondria found throughout their cytoplasm. Puzzling lamellar whorls are described in the cytoplasm of some oxyphil cells. The endothelium of parathyroid capillaries is extremely thin in some areas and contains numerous fenestrations as well as an extensive system of vesicles. The possible significance of these structures is discussed. The connective tissue elements found in the perivascular spaces of macaque parathyroid are described.

Effect of thyroxine on the ultrastructure of the hypophyseal proximal pars distalis in Tilapia zillii

1975 ◽  
Vol 53 (6) ◽  
pp. 686-690 ◽  
Author(s):  
John F. Leatherland ◽  
Mohamed Hyder
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Cell Types ◽  
Pars Distalis ◽  
Tilapia Zillii ◽  
Thyroid Axis ◽  
And Control ◽  
Granule Release

The effects of exogenous L-thyroxine on the fine structure of the proximal pars distalis cells were examined in Tilapia zillii. In thyroxine-treated animals the thyrotrophic cells appeared marginally smaller and less active whereas the somatotrophs appeared markedly more active, with increased endoplasmic reticulum, larger mitochondria, and more granule release when compared with the same cell types in control animals. The gonadotrophs were similar in appearance in both thyroxine-treated and control groups.The possible interrelated activity of the somatotrophs and the TSH–thyroid axis is discussed.

CHANGES IN CELL FINE STRUCTURE OF LIMA BEAN AXES DURING EARLY GERMINATION

1966 ◽  
Vol 44 (3) ◽  
pp. 331-340 ◽  
Author(s):  
Shimon Klein ◽  
Yehuda Ben-Shaul
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Cell Walls ◽  
Lipid Droplets ◽  
Lima Bean ◽  
Amorphous Substance ◽  
Golgi Bodies ◽  
Early Germination ◽  
Almost All ◽  
Vacuolar Content

Changes in cell fine structure were studied in axes of green lima bean seeds soaked in water for 1–48 hours. At the beginning of the imbibition period the cortical and pith cells and to a smaller degree the cells of the future conductive tissues contain several vacuoles filled with an amorphous substance. Almost all of the cells contain lipid droplets arranged exclusively along cell walls. The endoplasmic reticulum appears in the form of long tubules, predominantly occupying the peripheral parts of the cell, surrounding the nucleus. A large concentration of ribosomes, mostly unattached, can be found in the cytoplasm. Similar particles make up the bulk of the nucleolus, but could not be found in plastids, which frequently contained starch, but were devoid of internal membranes. Only very few Golgi bodies occur. No changes in fine structure seem to occur during the first 4 hours of imbibition, but after 24 hours the lipid droplets and the vacuolar content have disappeared, the endoplasmic reticulum is more evenly distributed throughout the cells, and a large number of Golgi bodies can be seen.

scholarly journals THE FINE STRUCTURE OF THE RAT CEREBELLUM

1964 ◽  
Vol 23 (2) ◽  
pp. 277-293 ◽  
Author(s):  
Robert M. Herndon
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Light Microscope ◽  
Osmium Tetroxide ◽  
Granule Cells ◽  
Cell Types ◽  
Bergmann Glia ◽  
Rat Cerebellum

This paper describes the fine structure of the granule cells, stellate neurons, astrocytes, Bergmann glia, oligodendrocytes, and microglia of the rat cerebellum after fixation by perfusion with buffered 1 per cent osmium tetroxide. Criteria are given for differentiating the various cell types, and the findings are correlated with previous light microscope and electron microscope studies of the cerebellum.

scholarly journals MORPHOLOGIC AND CYTOCHEMICAL IDENTIFICATION OF PEROXISOMES IN THE RAT PAROTID AND OTHER EXOCRINE GLANDS

1973 ◽  
Vol 21 (2) ◽  
pp. 131-141 ◽  
Author(s):  
ARTHUR R. HAND
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Exocrine Glands ◽  
Widespread Occurrence ◽  
Duct Cells ◽  
Low Concentrations ◽  
Endogenous Peroxidase ◽  
Rat Parotid

Peroxisomes were identified in all three parenchymal cell types of the rat parotid gland. They averaged 0.33 µ in diameter in the acinar and intercalated duct cells, and 0.22 µ in the striated duct cells. They were closely related to the endoplasmic reticulum, occasionally in continuity with smooth surfaced cisternae and often embraced by ribosome-free portions of endoplasmic reticulum which paralleled their membrane. Glutaraldehyde fixation inhibited the endogenous peroxidase of the parotid gland and allowed visualization of the peroxisomes following incubation in alkaline diaminobenzidine medium. Peroxisomal staining was unaffected by varying H2O2 concentrations or low concentrations of KCN, but was prevented by aminotriazole and dichlorophenolindophenol. Examination of other exocrine glands after incubation in diaminobenzidine medium revealed the presence of peroxisomes in the pancreas, submandibular, lacrimal, nasal mucosal and von Ebner's glands. These studies indicate that peroxisomes are of widespread occurrence in exocrine tissues of the rat.

Fine Structure of the Ultimobranchial Gland in the Chick

1971 ◽  
Vol 29 ◽  
pp. 510-511
Author(s):  
A. S. Chan
Keyword(s):  
Fine Structure ◽  
Epithelial Cells ◽  
Cell Membrane ◽  
Electron Density ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Dark Cells ◽  
Ultimobranchial Gland

Although the ultimobranchial gland of the chick has been shown to contain large amounts of calcitonin relatively few reports have been published on its fine structure. In the present study, the ultrastructure of the chick ultimobranchial gland, with emphasis on the cells which appear to be the producers of the hormone, will be examined. Ultimobranchial glands were obtained from twenty 2-week-old chicks and fixed in glutaraldehyde followed by osmium tetroxide.The gland is composed of aggregate of cords and clusters of cells interspersed with variable numbers of cyst-like cavities. Two parenchymal cell types, namely, light and dark cells can be recognized (Figs. 1,2,3). Epithelial cells, varying from columnar to cuboidal, line the cavities of the cysts.Light cells form the majority of the cell types (Fig. 1). The cytoplasm is characterized by the presence of membrane-limited secretory granules, measuring from 100 to 350 mμ in diameter. The contents of the secretory granules vary in electron density from moderate to extreme (Figs. 1,2). Secretory granules are distributed randomly in the cytoplasm although some are lined near the cell membrane.

Fine structure of the thraustochytrid Ulkenia amoeboidea. II. The amoeboid stage and formation of zoospores

1982 ◽  
Vol 60 (7) ◽  
pp. 1103-1114 ◽  
Author(s):  
S. Raghu Kumar
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Fine Structure ◽  
Nuclear Division ◽  
Smooth Endoplasmic Reticulum ◽  
Dense Granule ◽  
Multivesicular Bodies ◽  
Golgi Bodies ◽  
Dense Bodies ◽  
Spindle Microtubules

In the thraustochytrid Ulkenia amoeboidea (Bahnweg & Sparrow) Gaertner the contents of the mature vegetative thallus escape from the cell wall in the form of a limax cell. The limax cell is covered by a layer of scales and possesses a nucleus, a paranuclear body, Golgi bodies, mitochondria, bands of smooth endoplasmic reticulum, vacuoles, multivesicular bodies, and cisternae with filamentous contents. The posterior end is filled with smooth endoplasmic reticulum and fusiform vesicles. The anterior end is organelle free and filled with cytoplasm with free ribosomes. Subspherical dense bodies, bounded by a single membrane, are present. The limax cell rounds up prior to mitosis and the Golgi bodies increase in number. During mitosis, the nuclear membrane breaks down totally. Chromosomes are not well defined. Spindle microtubules arise from the centriole and enter the nucleus. After nuclear division, the nuclear envelope is reformed. Cytokinesis is by cleavage into two cells, accompanied by formation of microtubules along the cleavage furrows. The zoospore possesses a nucleus, a paranuclear body, mitochondria, vesicles with presumptive mastigonemes and kinetosome rootlet microtubules and they are covered by a layer of scales. An electron-dense granule and two peripheral thickenings are present within the lumen of the kinetosome.

Insect frontal ganglion: fine structure of its neurosecretory cells in diapause and non-diapause larvae of Diatraea grandiosella

1975 ◽  
Vol 53 (8) ◽  
pp. 1093-1100 ◽  
Author(s):  
C.-M. Yin ◽  
G. M. Chippendale
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Neurosecretory Cells ◽  
Granular Endoplasmic Reticulum ◽  
Diatraea Grandiosella ◽  
Corn Borer ◽  
Golgi Bodies ◽  
Juvenile Hormone Mimic ◽  
Frontal Ganglion ◽  
Southwestern Corn Borer

The fine structure of the neurosecretory (NS) cells of the frontal ganglion (FG) of diapause and non-diapause mature larvae of the southwestern corn borer, Diatraea grandiosella, was compared. Two large (15- to 20-μm diam) NS cells are typically found in each FG. Their cytoplasm stained deeply purple with paraldehyde fuchsin and contained granules 1500–2500 Å in diameter. The granules in the NS cells of non-diapause larvae were often associated with Golgi bodies whereas those of the diapause larvae were associated with dilated cisternae of the granular endoplasmic reticulum. Fewer Golgi bodies were observed in sections of NS cells of the FG of diapause larvae than in those of non-diapause larvae. Sections prepared from diapause larvae obtained conventionally by exposure to low temperatures, and experimentally by treatment with a juvenile hormone mimic, gave similar results.Our findings show that granules accumulate in the perikaryon of the NS cells of the FG of diapause larvae and suggest that the granular endoplasmic reticulum is involved in their formation. The shutdown of the transport of these NS granules from the FG appears to be a factor in some yet to be determined phase of the neuroendocrine regulation of diapause.

scholarly journals THE FINE STRUCTURE OF OSTEOBLASTS IN THE METAPHYSIS OF THE TIBIA OF THE YOUNG RAT

1961 ◽  
Vol 9 (3) ◽  
pp. 583-595 ◽  
Author(s):  
D. A. Cameron
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Light Microscope ◽  
Bone Matrix ◽  
Organic Matrix ◽  
Striking Feature ◽  
Cell Organelles ◽  
Phosphate Ions ◽  
Fine Structures ◽  
Young Rat

The appearance of osteoblasts after fixation with OsO4 is described in this paper. They have the basic structures found in other types of cells. The most striking feature is the array of rough-surfaced membranes of the endoplasmic reticulum; this feature is in keeping with the osteoblast's function of producing collagen as the bone grows. The sacs formed by these membranes probably represent the protein-containing granules described by other workers using the light microscope. They contain fine fibrillary material, and similar fibrils are to be found free in the cytoplasm. These fibrils could be tropocollagen units, although fibrils recognizable as collagen by their structure are found only outside the cell. The arrangement of the cell organelles does not seem to be related to the formation of collagen, but correlation of the fine structures of the cells with the histochemical and cytochemical findings in these cells reported by other workers leaves no doubt that they are directly concerned in the production of the organic matrix. It has not been possible to show that osteoblasts influence the passage of calcium or phosphate ions from the blood to the bone matrix.

A preliminary study of the fine structure of the oökinete, oöcyst, and sporozoite formation of Leucocytozoon simondi Mathis and Leger

1968 ◽  
Vol 46 (3) ◽  
pp. 303-307 ◽  
Author(s):  
Sherwin S. Desser ◽  
K. A. Wright
Keyword(s):  
Energy Source ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Epithelial Cells ◽  
Cell Membrane ◽  
Light Microscope ◽  
Dense Material ◽  
Blue Staining ◽  
Preliminary Study

The major features of the cytology of oökinetes, oöcysts, and sporozoites of Leucocytozoon simondi Mathis and Leger as seen in KMnO4-fîxed midguts of Simulium rugglesi and examined in the electron microscope, are related to their appearance in Giemsa-stained light microscope preparations. Thus, blue-staining regions of oökinete and oöcyst and the posterior, darkly stained region of sporozoites correspond to regions of endoplasmic reticulum; light "vacuole-like" regions correspond to accumulations of dense material which were not membrane enclosed; and minute red-stained spots at the anterior tip of sporozoites correspond to paired organelles. The dense material of oökinetes which, in oöcysts, is segregated into developing sporozoites may function as an energy source for sporozoites. The structure and development of these stages is similar to that of Plasmodium spp. The oöcyst of L. simondi develops extracellularly, enclosed by the basal lamina of the midgut with most of its surface surrounded by the basal cell membrane of midgut epithelial cells. This location of the oöcyst may be important in determining the subsequent pattern of development of this species.

Cytoplasmic Microtubules in the Leaf Glands of Phaseolus Vulgaris

1967 ◽  
Vol 2 (4) ◽  
pp. 557-562
Author(s):  
T. P. O'BRIEN
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Phaseolus Vulgaris ◽  
Virus Infection ◽  
Light Microscope ◽  
Cytoplasmic Streaming ◽  
Cortical Microtubules ◽  
Cellular Asymmetry ◽  
Perinuclear Cytoplasm ◽  
Cytoplasmic Microtubules

Preliminary observations on the fine structure of the club-shaped glands on Phaseolus vulgaris leaves are reported. The perinuclear cytoplasm of the apical cells of these glands contains an abundance of microtubules. These occur either as aggregates of 2-8 or more tubules, or they may be organized around a central core of material to form a fibre-like structure. The cells also contain cortical microtubules and are rich in rough endoplasmic reticulum and dictyosomes. The nuclei of these cells also contain a proteinaceous fibre, visible in the light microscope. The possible significance of these structures is discussed in relation to cytoplasmic streaming, maintenance of cellular asymmetry, and reaction to virus infection.

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