摘要:

AbstractThe pineal region of four adult maleProcavia capensisfrom South Africa was studied in serial sections of median portions of entire brains. A consistent and unique pineal morphology was found in all specimens, in contrast with previous reports based on specimens ofProcaviafrom diverse and distant populations or species. A principal pineal tissue mass bounds the pineal recess anterodorsally and makes contact with the subcommissural organ at the apex of the recess. A dorsal or accessory pineal tissue mass occurring on the opposite (anterior or dorsal) side of the habenular commissure forms part of the basal wall of the dorsal sac. Both pineal parts are penetrated throughout by nerve fibers, of which at least the great majority belong to the habenular commissure system. Tissue zonation, rich and distinctive vascularization, abundant pinealocytes in lobules, and parenchymal follicles are also characteristic. The dorsal sac and pineal recess are unusually large in this species. Additional features of the pineal body, dorsal sac and subcommissural organ are described.

ISSN:0002-9106    

DOI:10.1002/aja.1001300402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe structure of the renal calyx, pelvis and upper ureter has been investigated in the adult rabbit. The methods employed for light microscopy were designed to demonstrate smooth muscle, cholinesterase and catecholamine‐containing nerves, elastic and collagenous fibers, and glycogen. Selected areas of the upper urinary tract were also examined using the electron microscope. The wall of the calyx and pelvis includes two layers of muscle cells the inner one of which appears to be continuous with the muscle coat of the ureter. The external layer extends across the renal pelvis from the calyx and ends abruptly in the pelvi‐ureteric region. In some regions cells from this layer run towards and intermingle with the muscle of the inner layer. The muscle cells forming the outer layer are associated with many adrenergic nerves which run in the connective tissue separating individual muscle cells. Numerous elastic fibrils are closely related to these cells which usually contain glycogen. In contrast, the muscle cells forming the inner layer of the pelvis and those of the upper ureter have a relatively poor innervation, are closely packed together without intervening connective tissue, and are usually devoid of glycogen. These observations provide structural evidence in support of the concept that specific regions of the renal calyx and pelvis influence and possbily control the activity of the ure

ISSN:0002-9106    

DOI:10.1002/aja.1001300403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractPrevious experiments have suggested that the guinea pig chorio‐allantoic placenta is a barrier to the maternal‐fetal passage of proteins. The means by which the placenta exercises this barrier function were investigated by electron microscopy after injection of peroxidase, ferritin, and Thorotrast. Uptake of protein was by coated vesicles which formed at the trophoblast surface, pinched off, and migrated deeper into the cytoplasm. Some vesicles emptied into multivesicular bodies; others migrated across the trophoblast, emptying their content into the underlying compartment. Peroxidase and ferritin were observed in basement membranes within 10–20 minutes after injection. At longer intervals, the proteins were increasingly difficult to demonstrate in basement membranes, although increased amounts were present in the trophoblast. Neither the basement membranes nor the fetal capillary endothelium constituted an effective barrier to proteins which crossed the trophoblast. The results suggest that the trophoblast is the major barrier to maternal‐fetal protein transfer across the labyrinth. The trophoblast appears to exercise this barrier function by (a) having a low rate of protein absorption and (b) having multivesicular bodies and lysosomes which sequester and possibly degrade absorbed proteins. However, the trophoblast is not a complete barrier to the passage of these exogenous proteins which may indicate a normal, albeit minor, pathway of maternal‐fetal protein

ISSN:0002-9106    

DOI:10.1002/aja.1001300404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe auriculotemporal nerve is commonly misrepresented in both illustrations and textual descriptions. Our 85 dissections of the nerve demonstrate that the roots of the “typical” auriculotemporal nerve do not form a tight “buttonhole” loop around the middle meningeal artery. Instead the roots outline an elongated V‐shaped interval with the roots widely separated from one another. At their junction the roots form a short trunk which immediately breaks up in line with the posterior border of the mandible into a spray of branches. The superficial temporal ramus of the auriculotemporal nerve should not be considered as the main continuation of the nerve, but merely as its largest branch. A substantial portion of the nerve makes up its two communicating rami with the facial nerve; these are the strongest and most consistent of the many peripheral communications between trigeminal and facial nerves. Common variations in configuration, branching, and relationships of the nerve are

ISSN:0002-9106    

DOI:10.1002/aja.1001300405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe morphogenesis of the extra‐embryonic circulatory system of the chick was studied by light and electron microscopy, from precirculatory stages until the beginning of the definitive circulation. Early mesodermal migrations of prospective vasoformative cells and formation of blood islands take place with minimal morphologically expressed cytodifferentiation. The earliest mesodermal clusters are not syncytial. Formation of vascular lumina is not due to lysis of central cells. Undifferentiated mesenchyme possesses the capacity to establish complex junctional devices at points of contact with like cells. The first formed blood islands show intimate relationships with endoderm. The initial capillary network is sinusoidal in type, the endothelium being unsupported by a basement membrane. The major vitelline vessels acquire a more complex anatomy but the capillaries retain this simple pattern throughout the period studied. Several phases in the histogenesis of vitelline vessels are recognized, which could be correlated with the known progression of arterial pressure patterns. Continuing differentiation and mesenchymal investment of vascular walls, after stages 22–23 of Hamburger and Hamilton ('51), in correspondence with the last sustained pressure elevation, leads to completion of the adult vascular struct

ISSN:0002-9106    

DOI:10.1002/aja.1001300406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractDifferentiation of the Leydig cell in the fetal mouse as studied by light and electron microscopy was divided into three phases. During phase 1 (day 12 to day 15) the spindle‐shaped cell becomes an immature Leydig cell which contains numerous free ribosomes and some polysomes. Phase 2 (day 16 to day 19) is marked by a considerable development of smooth endoplasmic reticulum and by an equally important decrease in ribosomal population. Mitochondria are increased in number 100%. Phase 3 (day 19 to birth) is characterized by maximal lipid and glycogen content. Close to the time of birth, smooth endoplasmic reticulum decreases in extent and becomes vesicular.The peak in prenatal Leydig cell differentiation as judged by development of the endoplasmic reticulum occurs during phase 2. These findings are discussed in the light of data derived from study of other species and an attempt is made to correlate morphological features with available information concerning the control of differentiation by gonadotropin

ISSN:0002-9106    

DOI:10.1002/aja.1001300407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractTwo cases of split hand and foot anomaly in maleMacaca mulattaare described. Radiographs and dissection of the muscular anatomy of the first case showed that the muscular changes could be directly related to the osseous deformities. Comparison of the anatomy of case 1 with that of two other nonhuman primate cases on record suggests that two different developmental patterns and possibly two different genotypes may underlie the anatomical differences observed. The second case of the anomaly has been sent to the University of Washington Medical Lake Breeding Facility where it is hoped future pedigree data may provide information on some of the embryological and genetic questions raised by the existing materials.

ISSN:0002-9106    

DOI:10.1002/aja.1001300408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001300401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY