American Journal of Anatomy

doi: 10.1002/aja.1001400101pmid: N/A

Dym, Martin

doi: 10.1002/aja.1001400102pmid: 4132933

The monkey testis contains an axial rete in a highly vascular central core of loose connective tissue. Seminiferous tubules join the rete along its entire length. The short terminal segments of the tubules are lined mainly by Sertoli cells. There is then a transition from Sertoli cell epithelium to the simple cuboidal epithelium of tubuli recti, which connect the seminiferous tubules to the rete testis.

Rambourg, A.; Clermont, Y.; Marraud, A.

doi: 10.1002/aja.1001400103pmid: 4132934

Osmication in an unbuffered aqueous solution of osmium tetroxide allows the forming face of the Golgi apparatus to be labeled in many cell types. This property was utilized to study the spatial configuration of this organelle by examining stereopairs of the same field taken at 1,000 KV after tilting a thick (1 to 7 μUm) section of − 7° or + 7° from the original (0°) position. When examined in 1 μm thick sections at magnifications ranging from 13,000 to 18,000 times, the osmic acid‐impregnated element of the Golgi apparatus of ganglion nerve cells, Leydig cells or Sertoli cells takes the appearance of a single layered polygonal network of tubules. This network can only be seen at electron microscope magnifications and is referred to as the primary network or structure of the forming face of the Golgi apparatus. When 2 to 7 μm thick sections are examined under progressively lower magnifications, the details of the primary structure remain discernible but become less conspicuous. The osmiophilic portion of the Golgi apparatus now extends over large areas of the cytoplasm to form an extensive continuous structure. This structure which is in the range of visibility of the light microscope is referred to as the secondary network or structure of the forming face. In ganglion nerve cells, the secondary structure consists of a perinuclear network showing slender projections reaching the nucleus and wider expansions approaching the cell surface; in the Leydig cells it appears as an ovoid structure located at one pole of the nucleus whereas in Sertoli cells it forms a cylindrical structure located in the main shaft of the cytoplasm and extending from the nucleus towards the lumen of the seminiferous tubule. Thus the forming face of the Golgi apparatus displays a primary structure; the tubular roughly polygonal network, which is similar in the three cell types and a secondary structure which varies from cell to cell.

Dowd, David A.

doi: 10.1002/aja.1001400104pmid: 4596335

The coronary arteries and veins are described in the phalanger (Trichosurus vulpecula), an Australian marsupial, after study of 16 hearts. Several hearts were prepared by injection of the vessels with either latex or vinyl plastic.

Scadding, Steven R.; Liversage, Richard A.

doi: 10.1002/aja.1001400105pmid: 4824764

The responses of the oviduct and the male ureter to transection were studied histologically. The ureter regenerates by the formation of a blastema, then the development of a bridge of cells between the cut ends, and finally by restoration of the lumen. Seven out of 12 cases fixed 30 to 40 days after transection had reconstituted the lumen and four of the remaining five cases had the two ends joined and would likely have regenerated if they had not been fixed. In contrast, the oviducts did not appear to have any regenerative capacity; only two out of the 17 cases fixed 31 to 41 days after transection exhibited some reconstitution. The transected oviducts did not form a blastema or give any evidence of cellular dedifferentiation.

McMillan, Paul J.; Hooker, William M.; Deftos, Leonard J.

doi: 10.1002/aja.1001400106pmid: 4824765

Human thyroid glands obtained within 2.5 hours of death were examined for the presence and distribution of calcitonin‐containing cells using horseradish peroxidase as an indicator in an indirect immunohistochemical procedure. The glands were cut into 10 to 20 transverse slices per lobe and fixed in glutaraldehyde. A representative section of each paraffin‐embedded slice was processed and systematically scanned for calcitonin‐containing cells. Of 13 glands examined, ten contained calcitonin cells. The cells were found mostly in the follicular epithelium both singly and in groups. They were most numerous in the central region of each lobe of the gland. The isthmus and poles were devoid of calcitonin cells and only occasionally were these cells found at the surface. Parathyroid glands were examined by the same procedure for the presence of calcitonin cells but none were observed. These results demonstrate that calcitonin‐containing cells are found regularly in human thyroid glands and that the distribution of these cells is centered in the central region of each lobe of the gland.

Andrews, Peter M.; Porter, Keith R.

doi: 10.1002/aja.1001400107pmid: 4132935

Scanning electron microscopy was used to study the ultrastructural morphology of the nephron. Material for observation was taken from rat kidneys which were fixed by vascular perfusion. Different techniques for splitting open the kidney, combined with stereoscopic viewing, provided many instructive views of nephron morphology. In addition, scanning electron microscopy revealed a number of new features including (1) the complex organization and structure of kidney podocytes; (2) the distribution of endothelial pores and the presence of endothelial microprojections and branching endothelial thickenings; and (3) the presence, distribution and morphology of microprojections and cilia on the luminal surfaces of Bowman's capsule and the uriniferous tubules.

Bagwell, J. N.; Leavitt, W. W.

doi: 10.1002/aja.1001400108pmid: 4824762

Embryos from timed matings were studied at days 12–24 of gestation with respect to crown‐rump length and external appearance. A linear increase in length was observed from the twelfth (2.5 mm) to the twenty‐fourth (27.7 mm) day with the largest increases occurring between days 20 and 21 (3.8 mm) and days 22 and 23 (4.2 mm). The smallest daily increases were observed between days 15 and 16 (1.01 mm) and days 21 and 22 (1.03 mm), while the average daily increment for the remaining days was between 1.5 mm and 2.5 mm. Major changes in external appearance occurred on days 13, 14, 17 and 20 of gestation. Those features which could be observed externally were described for each of the days during the period studied. Late prenatal development in the gerbil resembles that of other myomorph rodents but proceeds at a slower rate than in other species such as the mouse or hamster. This slower rate of development may be of value when precise timing of drug administration and recovery of embryos is necessary.

Paull, Willis K.; Scott, David E.; Boldosser, W. G.

doi: 10.1002/aja.1001400109pmid: 4824763

A nidus of supraependymal cells was located within the infundibular recess of a rat's third ventricle. Upon transmission electron microscopic analysis, these cells were clearly identified as neurons. Neuronal processes, as well as end‐terminals that contained dense‐core and clear synaptic‐like vesicles, were also observed coursing around these cells. It is suggested that some of the supraependymal cells that have been observed in previous scanning electron microscopic studies could be neurons similar to those described here.

Marrtinez, I. Richardo; Pekarthy, James M.

doi: 10.1002/aja.1001400110pmid: N/A

The ultrastructure of a specialized encapsulated nerve ending located in the papillary layer of rat gingiva is described. The axon in the corpuscular ending possesses microvesicles and microtubules, and is surrounded by laminar cells (with basement membrane) and capsular cells (modified fibroblasts, no basement membrane).