摘要:

The author studied the structure of the tissue components of the tunicae of the terminal segment of the sigmoid sinus, particularly at the level of the transition between the sigmoid sinus, the superior bulb of the jugular vein and the first portion of the human internal jugular vein; it was established that the transition between the sigmoid sinus and the first portion of the internal jugular vein occupies the whole extension of the superior bulb of the jugular vein up to the inferior third of the first portion of this vessel. These vascular walls exhibit a structure similar to that of the dura, i.e. the tunica adventitia is formed by fascicles of collagenic fibers which describe discontinuous spirals, more open proximal to the beginning of the first portion of the internal jugular vein. Approximately in the inferior third of the first portion of the internal jugular vein, there appear fascicles of smooth muscle fibers which are arranged similarly to those of the venous walls. The tunica intima of these vascular segments exhibits an endothelium resting on a network of elastic fibers which may play the role of an internal elastic lamina. From the bony border of the jugular foramen there originates a connective system whose fascicles of collagenic and elastic fibers incorporate to the wall of the internal jugular vein after describing a stretch in spiral around the vascular lumen.

ISSN:1422-6405    

DOI:10.1159/000145116

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

A plausible hypothesis as to the mode of action of dexamethasone (DXM) has been proposed. Growth of irradiated tadpoles of Bufo melanostictus treated daily with the corticoid, is more suppressed. Compared with its antagonism with ACTH, its coordinate promotion of TSH production accelerates metamorphosis. This modulated feedback is consistent with the constant course of the hypothalamic nuclei influence upon the adenohypophyseal hormones.

ISSN:1422-6405    

DOI:10.1159/000145117

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The morphology of apocrine sweat glands in two breeds of cattle, the White Fulani and Friesian was studied histologically using biopsy midside skin samples obtained from the animal at 6.00 a.m. (period 1), 2.30 p.m. (period 2) and 4.00 p.m. (period 3), respectively. Sweat glands with three morphologic types of epithelium were observed. Type 1 consisted of flattened low cüboidal epithelium. Type 2 had tall cuboidal epithelium with cell apical borders slightly indented and the gland lumen narrower than in type 1. A third group of glands had tall columnar epithelial cells (type 3) with bleb-like protuberances on their luminal surfaces. There were also corresponding changes in the morphology of myoepithelial cells from an elongated form in type 1 to a contracted form in types 2 and 3. The morphology of secretory cell surfaces was found to vary with the sampling period; a greater percentage of type 1 glands was seen in period 1 and a preponderance of types 2 and 3 glands (in varying proportions) in periods 2 and 3. Breed differences in the distribution of type of epithelium at various sampling periods were observed. These results are discussed in relation to the functional activity pattern of the sweat glands on stimulation by heat

ISSN:1422-6405    

DOI:10.1159/000145118

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The mucosa of the small and large intestine of goat fetuses exhibited villi which had disappeared after the 32.5-cm curved crown rump (CVR) stage. At places, the stratified epithelial lining persisted among the normal columnar epithelium with goblet cells. The concentration of goblet cells increased with age, while the thickness of the epithelium decreased. The crypts of Lieberkühn were tortuous at the base. Brunner’s glands appeared at the 14.2-cm CVR stage. Peyer’s patches appeared at the 24.5-cm CVR stage in the ileum. The muscularis mucosae differentiated in the large intestine in group II (16.2- to 24.5-cm CVR length) and progressed caudocranially. The striated border of the intestinal epithelium presented with alkaline phosphatase activity; this border and the goblet cells also stained for mucin. Glycogen was demonstrable in the epithelium with greater concentrations in the duodenum and jejunum in group I (11.5-to 14.6-cm CVR length), and in the ileum and large intestine in group III (30.8-to 39.5-cm CVR len

ISSN:1422-6405    

DOI:10.1159/000145119

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

This investigation describes the ultrastructure of the atrioventricular node of Eptesicusfuscus. Two conducting cell types (nodal and transitional) are identified which differ in location, myofibrillar content, and types of intercellular junctions. Centrally located nodal cells display variable staining intensity and contain disorganized myofibrils which rarely form sarcomeres. Desmosomes and nexus-like junctions connect the nodal cells. Transitional cells, situated peripherally, exhibit distinct sarcomeres and are attached to the adjacent cells through desmosomes and underdeveloped intercalated discs. Longitudinal arrangement of the mitochondrial cristae is frequently seen in both cell types. In the connective tissue stroma, numerous capillaries (with micropinocytotic vesicles), axons, and possibly axonal terminals, some filled with vesicles, are observed. A large ganglionated nerve trunk is present on the nodal periphery. True nexuses and neuromuscular junctions are not observed. It is suggested that nodal cell types previously reported in different vertebrates under various names are merely simple variations of the two basic types of conducting cells – nodal and transitional. No interspecffic differences are observed between these cells of the big brown bat compared with those in other vertebrate

ISSN:1422-6405    

DOI:10.1159/000145120

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The author investigated in 130 anatomical specimens the topographical relations of the sciatic nerve and the musculus piriformis in order to explain the clinical syndrome of the m. piriformis. The author found that in 6.15% of cases the nervus peroneus communis passes between the tendinous parts of the m. piriformis, and he considers this variation of practical significance for the development of the ‘piriformis syndrome’. In unward rotation of the thigh, the m. piriformis is extended and the tendons of the divided muscle are tightly pressed together thus pinching the nerve between them. Pinching of the nerve causes the characteristic sciatic pain. In such a case, the patient can be relieved by cutting one of the tend

ISSN:1422-6405    

DOI:10.1159/000145121

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

From 64 consecutive autopsies of patients with neither testicular nor hormonal pathology, 26 showed extraparenchymal Leydig cells, located mainly in the epididymis and in the spermatic cord. The ultrastructural study of these specimens plus those obtained from 2 patients affected with functional testicular tumors leads to the following conclusions: (1) The origin of ectopic Leydig cells is not interstitial Leydig cells having infiltrated the testicular nerves and migrated along them towards ectopic locations. (2) The ectopic Leydig cells are considered to develop from undifferentiated precursor cells, located extraparenchymally, mainly inside and beside the testicular nerves. These precursor cells are similar to those observed in the testicular interstitium and have an ovoid shape and some cytoplasmic projections. The cytoplasm contains vesicles of smooth endoplasmic reticulum, lysosomes, lipid droplets and abundant microfilament bundles. The transformation from these cells into mature Leydig cells implies a progressive differentiation of the cytoplasmic components involved in steroid biosynthesis.

ISSN:1422-6405    

DOI:10.1159/000145122

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The paper describes the ultrastructural changes of the sympathetic neurons following guanethidine administration in mice. The main characteristic changes, after prolonged administration (l-10weeks) of guanethidine (Ismelin Ciba-Geigy, Basel, Switzerland) at doses of 30–50 mg/kg/daý i.p. and i.m. were: (1) Mitochondrial damages: swelling and deformation of the mitochondria, with disruption and dispersion of the cristae and condensation or dissolution of the matrix. Membranolysis of the outer and inner mitochondrial membranes. (2) Neural processes: swelling and disorganization of the internal architecture in the postganglionic axonal and dendritic synaptic varicosities. (3) Adrenergic vesicles: disappearance of the granular vesicles in the early stage of the experiment, increase of the coated vesicles in the later stage of treatment. The effect of guanethidine is specific for the postganglionic adrenergic neurons, but the observed destruction is not caused solely by guanethidine; other chemical substances induce the same or similar degeneration in the sympathetic gangli

ISSN:1422-6405    

DOI:10.1159/000145123

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The primate nasopharynx-auditory tube-middle ear complex is being used by several researchers to model both normal and pathologic functions of the human auditory tube. An extensive search of the literature has indicated little detailed information on the primate tube/middle ear system. This study was undertaken to define the anatomical characteristic of the system in the rhesus monkey (Macaca mulatta) and to determine the limits on the use of the monkey as a model of human tubal function. Although the direct application of morphologic data to account for the observed function of a system is a tenuous one, the data on the rhesus monkey auditory tube appear to be consistent with those published for other mammals. The tensor veli palatini muscle appears to be the only muscle to act directly on the tube and effect tubal dilation. The muscle is attached to the lateral membranous tubal wall along its extrabullar extension. The muscle has an inferior attachment to the posterior hard palate and thus possesses a vector directed inferolaterally; contraction would appear to pull the membranous wall inferiorly and laterally, resulting in tubal dilation. The auditory tube relationships of the salpingopharyngeus, levator veli palatini, and internal pterygoid muscles are described. Their possible role in primate tubal function is minimal at best.

ISSN:1422-6405    

DOI:10.1159/000145124

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Mature placental material of full-term spontaneous births and 4-, 6-, 8- and 10-week-old placentas obtained from curettage cases were fixed in glutaraldehyde and osmium tetroxide for SEM examination. In young placentas, the ramifications of the chorionic villi start in the form of buds. The buds are transformed into tendrils with swollen extremities. These swellings resemble buds ready to bloom. The villi intertwine in different positions; both the villi and their tendrils are covered with dense layers of microvilli. In mature placentas, the surfaces of the chorionic villi and their ramifications are covered with microvilli. However, in comparison with the microvilli of young placentas, the microvilli here are less numerous and shorter. Imaginations were clearly visible on the surfaces of the villi; younger and newly budding microvilli, similar to those observed in young placentas, were seen in the invaginated regions. We had the impression that the mature placentas must regenerate in order to meet the increasing physiological requirements of the fetus.

ISSN:1422-6405    

DOI:10.1159/000145125

出版商:S. Karger AG    

年代:1979

数据来源: Karger