摘要:

Latimeria chalumnae Smith, the only surviving crossopterygian, possesses a well-developed, unpaired, postanal gland whose function is as yet undocumented. The availability of tissues suitable for ultrastructural and histochemical studies from the recent International Comores Expedition has permitted a reappraisal of the comparative morphology and functional hypotheses relating to the postanal gland. The richly vascularized tubuloacinar postanal gland is composed of cells which show the characteristic specializations of active ion transport. These include complex and extensive development of basal and lateral cell membrane infolding (cisternae) which are closely associated with numerous large, dense mitochondria. Histochemical studies have shown a high level of ATPase activity within the gland cells. These features of the postanal gland correlate well with those of the rectal glands of elasmobranchs and suggest a similar role in ion excretion and osmoregulation.

ISSN:1422-6405    

DOI:10.1159/000145050

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The origin, pattern of distribution and the length of the convoluted part of the testicular artery were examined by blunt dissection and by the preparation of arterial casts with vinylite. The testicular artery originates from the abdominal aorta just cranial to its bifurcation and forms compact coils and reveals a tortuous course in the region of the pampiniform plexus and along the attached border. The artery divides at the caudal extremity of the testis into 2–4 branches. The epididymal artery, which is a branch of the testicular artery, was seen to anastomose with the deferential artery, but no anastomosis occurs between these arteries and the testicular artery. The convoluted part of the testicular artery was 20 cm in length, but when unravelled totalled 240 cm. This is not affected by seasonal variations. The possible significance of these results was discussed and compared with similar findings of other mammal

ISSN:1422-6405    

DOI:10.1159/000145051

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Transformation of the rete ovarii into a rete testis and of the epoophoron into an epididymis after experimental sex reversal in Gallus domesticus is described. After castration of female chicks, the medulla of the left ovary and/or the right gonadal rudiment develop into a testoid or an ovotestis. From general view, this is observed as sex reversal. In case of formation of a testoid, the epoophoron develops into an epididymis and the rete ovarii develops into a rete testis which consists of intra- and extratesticular and intracapsular parts. Thus, a luminated duct system is developed which allows the transport of semen. In case of formation of an ovotestis, the discontinuously side-by-side located parts of the rete ovarii and of the epoophoron are maintained.

ISSN:1422-6405    

DOI:10.1159/000145052

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The effect of a subtotal vagotomy on the function of the intramural nervous system of different parts of the intestinal tract is studied by means of quantitative measurements of the acetylcholinesterase (AChE) activity. By sham vagotomy it was possible to explore the effect of narcosis and laparotomy on the intramural nervous system of the intestine. Vagotomy is followed by a decrease in AChE activity of the ganglionic cells in all parts of the intestinal tract. A minimum of activity, about 50% of the normal concentration, is attained at the 16th postoperative day. After this time, a continual increase in AChE activity, along with a reactivation of the function of the ganglionic cells, can be observed. 90 days after vagotomy the ganglionic cells of the intramural nervous plexus show a normal enzyme activity. These results support the hypothesis that most of the cells of the myenteric plexus build up an autonomic nervous plexus, which is stimulated in an excitatory way by the vagus nerve and which will be inhibited by sympathetic stimulation.

ISSN:1422-6405    

DOI:10.1159/000145053

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The technique of microdissection and the structure of nephrons and collecting ducts from normal kidneys were studied. The structure of the assumedly normal nephrons and collecting ducts is characterized by the uniformity of the outlines of the tubules. The various parts of the tubules are distinguished by the differences in diameter and epithelial structure.

ISSN:1422-6405    

DOI:10.1159/000145054

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The acid phosphatase reaction, applied to light and electron microscopy, was studied in the chicken pineal gland from the moment of hatching until 2 months of age. From the moment of hatching there is a great amount of acid phosphatase, which is mainly found in the vicinity of the lumen of both the recess and large follicles. Acid phosphatase is poor in the parafollicular layer. From day 30 onwards, there is an obvious fragmentation of the recess and of large follicles. Also, the parafollicular layer differentiates to form new follicles. The dense polymorphous bodies of the B pinealocytes are ultrastructurally identified as lysosomes.

ISSN:1422-6405    

DOI:10.1159/000145055

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

40 pelvic preparations of rabbits (Oryctolagus cuniculus) were bilaterally studied by dissection under the stereomicroscope and angiography. The arterial pattern of the pelvis, i.e. origin and branching of the umbilical, urogenital and internal pudendal arteries (visceral branches), is described. The main characteristics observed are as follows: (1) The umbilical artery is permeable in adults and gives origin to the cranial vesical artery and a caudal branch that irrigates the pelvic urogenital organs and, eventually, the rectum, with six patterns of branching in both sexes. (2) Usually, the urogenital artery is the continuation of the visceral branch of the internal iliac artery. In 1 animal, unilaterally, it arises from the median sacral artery. In 12 animals (6 bilaterally and 6 unilaterally) the urogenital artery is absent. When present, it forms two branches, a cranial and a caudal one, that irrigate of the urogenital organs in both sexes. (3) The internal pudendal artery is the direct continuation of the internal iliac artery and gives rise to some visceral branches that irrigate the penis, bulbourethral gland and rectum (with six patterns of branching) in males, and the vagina, clitoris and rectum (with three patterns of branching) in females.

ISSN:1422-6405    

DOI:10.1159/000145056

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The arterial pattern of the stomach of the North American beaver is studied by dissection of height specimens. The arrangement of the arteries resembles the typical mammalian pattern, although some variations are described. For example, the celiac artery gives off two large vessels, the cardiac and fundic arteries, which supply the corresponding regions of the stomach. Also, the right gastric artery originates from the gastroduodenal vessel instead of the hepatic artery.

ISSN:1422-6405    

DOI:10.1159/000145057

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Lens antigens, detected by immunofluorescence using rabbit antiserum against adult chick lens, appear in the chick embryo at stage 16. When eye rudiments are cultured in vitro, antigens developed; but they did not when optic cups were cultured but for a few cases. Isolated presumptive lens ectoderm from stage 4 did not develop antigens when cultured, but such ectoderm from stages 7–9 developed lens antigens and also showed lens structures. Stage 4 ectoderm could be induced to lens antigen development by alcohol-killed optic cups from stages 9–13. The experimental system can be used for in vitro studies on lens induct

ISSN:1422-6405    

DOI:10.1159/000145058

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

In the course of an investigation of the thalamic connections of the frontoparietal cortex in the albino rat, lesions were placed in the parietal cortex of adult rats, and the resulting terminal degeneration was observed in the ventrobasal complex, using the Fink-Heimer silver impregnation technique.Lesions made in the primary somatosensory forelimb region of the cortex result in a narrow band of terminal degeneration which extends dorsoventrally throughout the rostrocaudal two-thirds of the ventrobasal complex. This portion of the ventrobasal complex coincides with the electrophysiological representation of the thalamic primary somatosensory forelimb area, and corresponds closely to the medial portion of the lateral part of the ventrobasal complex as described by Smith, as well as to the medial portion of the posterolateral ventral nucleus according to Matano et al. These results serve to confirm the close correlation determined electrophysiologically between the topographical organization of the somatosensory forelimb areas of both the parietal cortex and the ventrobasal complex of the rat thalamus.

ISSN:1422-6405    

DOI:10.1159/000145059

出版商:S. Karger AG    

年代:1979

数据来源: Karger