摘要:

Observations with a dissecting microscope revealed a regular pattern of lobar development, from the centre outwards, for particular stages of development of the kidney in the embryo and fetus. A growth area near the poles is suggested, and further study is indicated to relate this to histogenesis. A formula is devised to facilitate the study of the lobation.

ISSN:1422-6405    

DOI:10.1159/000145544

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

This paper reports an anatomical study of the vascular supply in 60 human cerebelli from subjects of both sexes, aged between 20 and 60 years, who had died of various accidental causes. The origin, branching pattern and cortical and central distributions of the cerebellar arteries have been studied by gross dissection, vascular injection and corrosion procedures. Variations of the normal pattern of the cerebellar arteries in both origin and cortical distribution are frequently found, the anterior inferior and the posterior inferior cerebellar arteries being the arteries showing the highest number of variations. The anomalies most frequently found are duplication in the origin, abnormal origin, and the presence of hypoplastic vessels. The cerebellar nuclei were supplied by the rhomboidal artery, a collateral branch of the superior cerebellar artery. The formation of a precise segmentary vascular pattern into the dentate nucleus by branches arising from the rhomboidal artery is described. The results are discussed in the light of other anatomical studies.

ISSN:1422-6405    

DOI:10.1159/000145545

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The fine structure of the retinal epithelium, choriocapillaris, and Bruch’s membrane has been studied by electron microscopy in the domestic ferret. The ferret possesses a tapetum cellulosum in the superior fundus, and the morphology of the retinal epithelium and its associated structures varies depending upon its relation to the tapetum. Over the tapetum the retinal epithelium is a single layer of low cuboidal cells with basal infoldings and two types of apical process. Internally the cells are non-pigmented, display much smooth endoplasmic reticulum, little rough endoplasmic reticulum, lysosomes, phagosomes, and a basally located nucleus. The choriocapillaris is composed of large capillaries indented into the retinal epithelium. Bruch’s membrane is thin and composed of three layers. In non-tapetal regions the retinal epithelial cells are pigmented but display most of the other features noted over the tapetum. The choriocapillaris is not indented in non-tapetal areas. Bruch’s membrane appears identical to that noted over the tapetum. Wandering phagocytes are occasionally noted at the retinal epithelium-photoreceptor jun

ISSN:1422-6405    

DOI:10.1159/000145546

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Lysosomal hydrolases (e.g., acid phosphatase, AcPase; adenosine triphosphatase, ATPase, and lipase) and the mitochondrial ‘marker’ enzyme succinic dehydrogenase (SDH) were evaluated histochemically in the prostate gland of sexually ‘quiescent’ and ‘active’ bats. During the former state, AcPase activity was significantly less than in sexually active animals, suggesting that prostate AcPase activity is androgen dependent. Levels of lipase activity also were highest in the prostate of sexually active bats, suggesting the importance of endogenous lipids which may be mobilized and used as a source of energy. SDH and ATPase sites and patterns of distribution in the prostate gland of bats were closely similar during the two reproductive states. Differential enzymological patterns do not seem to have any significant correlation with the morphological changes which occur in the glandular epithelium, musculature, urethra and the luminal fluid, as the animals pass from a ‘quiescent’ phase to one of activity and vice versa as observed in th

ISSN:1422-6405    

DOI:10.1159/000145547

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Identification, total and differential counts of cell populations in guinea pig colostrum, milk and involution secretion were carried out. The cellular concentration in colostrum was high, but there was a dramatic decline in milk collected at the peak of lactation. Advancement of mammary gland involution was associated with a dramatic increase in cellular concentration. The neutrophil was the predominant cell type in colostrum, milk and early involution secretion. Macrophages were present at all stages of lactation and became the predominant cell as involution advanced. The proportion of lymphocytes was low and remained constant throughout the various stages of lactation. Small numbers of eosinophils and epithelial cells were present in most of the samples examined.

ISSN:1422-6405    

DOI:10.1159/000145548

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Study of intrarenal arterial segments of human kidney by the corrosion cast method has been carried out on 100 kidneys obtained within 24 h of death. The five arterial segments which are normally described, namely, apical, upper, middle, lower and posterior, were reduced to four in 46% of the kidneys due to either absence of the apical segment or fusion of the upper and middle or middle and lower segments. The number of segments was very rarely (1%) reduced to three due to the absence of the posterior and apical segments. The apical segment was absent in 15%. The upper and middle segments were combined in 14% and the middle and lower segments in 17%. The surface projections of different segments were variable depending upon the intrarenal branching pattern of the segmental arteries.

ISSN:1422-6405    

DOI:10.1159/000145549

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The results of a stereological analysis of cat carotid body type I cells are described. General ultrastructure is described as well as quantitative analysis of the cell organelles. Four types of nerve endings are identified on the basis of their synaptic membrane specialisations. 92.99% symmetrical (unclassifiable), 4.9% pre-synaptic, 1.5% post-synaptic, 0.6% reciprocal. The species difference in comparison to the rat is noted and locations of afferent and efferent terminations are discussed.

ISSN:1422-6405    

DOI:10.1159/000145550

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The dorsum of the opossum tongue shows filiform, fungiform, conical and three vallate papillae. An additional type, the compound filiform papilla, is characteristic of most marsupials, including the opossum. These are unique structures in which the epithelium forms fringe-like, keratinized projections around the apical borders of the papillae. The covering epithelium is an extensively keratinized, stratified squamous type with a well-developed stratum granulosum containing numerous keratohyalin granules. Large, heavily cornified conical papillae occur in a patch near the anterior end of the tongue and the apex of each papilla is directed posteriorly. Taste buds are associated with only the three vallate papillae which form a triangle near the base of the tongue. They are not present on the fungiform papillae or in the posterolateral mucosal folds which appear to replace the foliate papillae of other species.Introduction

ISSN:1422-6405    

DOI:10.1159/000145551

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

This work describes the use of an impression compound Silgel 604 to obtain casts of the intimal surface of the rabbit aorta distended to either systolic or diastolic in vivo diameter. Other rabbit aortas were fixed by glutaraldehyde at in vivo distensions. Specimens from these aortas were examined by scanning electron microscopy. Longitudinal folds were found in all cases at both diastolic and systolic distensions. The possible functions of the folds are discussed.

ISSN:1422-6405    

DOI:10.1159/000145552

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The sarcomere length of the rabbit pterygoid, temporal and digastric muscles was determined in seven mandibular positions. Six positions are representative of mastication, one of gnawing. Jaw displacement has a different effect in jaw openers (digastric and lateral pterygoid) and closers. The sarcomeres of the openers are long when the jaw is in molar occlusion and shorten relatively little at jaw opening. In the jaw closers they are very short in molar occlusion and become strongly extended when the mouth is open. Timing of electrical activity and sarcomere shortening corresponds closely. All muscles become active at sarcomere lengths of 2.6–3.1 µm. In the jaw closers, sarcomeres shorten till 2.1–2.3 µm during activity; in the jaw openers they do not shorten beyond 2.6–2.7 µm. Hence the openers remain close to optimum length (2.7 µm) while the closers shorten to lengths where possibly only 60% of the maximal isometric force can be exerted. During the initial phase of jaw closing, the medial pterygoid and temporalis shorten at speeds estimated to approach 50% of the presumed maximum speed. During the rest of the closing and power stroke, contraction takes place under near-isometric conditions, with little loss of force due to shortening. The jaw openers act at low shortening v

ISSN:1422-6405    

DOI:10.1159/000145553

出版商:S. Karger AG    

年代:1982

数据来源: Karger