摘要:

AbstractThe variation in the length of the pterygoid process was studied as a function of the sphenoid angle. Three hundred human skulls and ten skulls of certain animals (dog, sheep, pig, ox, horse) were appropriately measured. The length of the pterygoid process (lateral plate), was measured in all instances from the point of junction between the lamina and the greater wing of the sphenoid to the midpoint of the lower margin of the lamina. The average value of this dimension in man was 34.7 mm with variations from 28.0 mm to 44.5 mm.The average value of the length of the pterygoid process was found separately in male and female skulls; in different age groups; in skulls with narrow versus wide sphenoid angle; in skulls possessing a short versus a long nasion — basion distance. In each instance the values are compared and the standard deviation ascertained. The results of measurements made in man and animals are presented in a tabl

ISSN:0003-276X    

DOI:10.1002/ar.1091600302

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

年代:1968

数据来源: WILEY

摘要:

AbstractThe hepatic lobules of the family Suidae are unusually large, completely surrounded by fibrous tissue, and supplied by relatively large branches of the hepatic artery. The interlobular septa carry small branches of the artery, vein and bile ducts of the adjacent portal tracts and may be regarded as attenuated extensions of the portal tracts. The hepatic lobules of Tayassuidae and Hippopotamidae lack these distinctive features.

ISSN:0003-276X    

DOI:10.1002/ar.1091600303

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

年代:1968

数据来源: WILEY

摘要:

AbstractThe process of denucleation in normoblasts of fetal guinea pig liver was studied with electron microscopy employing serial sections. In the late normoblast the nucleus becomes eccentrically located in the cytoplasm. Continued maturation results in a nucleus which is protruding from the normoblast. Still later the nucleus separates from the remainder of the cell and is phagocytized by a reticular cell. Nuclei which have been extruded are surrounded by a narrow border of cytoplasm and possess a nuclear envelope, nuclear pores, and internal nuclear structure similar to that of normoblasts. The cytoplasmic border and nuclear structure are observed for some time after ingestion by reticular cells. Dissolution of nuclei inside the phagocytes is characterized by disappearance of the cytoplasmic border and nuclear envelope, loss of density of the chromatin, and appearance of dense particles in the interchromatin. It was concluded that under normal conditions, the sole mechanism of denucleation in definitive erythroblasts is extrusion. Mitochondria are partially degraded inside the late erythroblasts, forming a membranous residue which is later extruuded.

ISSN:0003-276X    

DOI:10.1002/ar.1091600304

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

年代:1968

数据来源: WILEY

摘要:

AbstractThis morphologic investigation was undertaken with an inbred strain of C57BL/10 male mice to examine the accumulation of lipofuscin in nerve cells of dorsal ganglia and the cerebellum at 4, 8, 20, and 30 months of age. Histological examinations revealed that at four months of age, cells contained only a few small sudanophilic bodies distributed fairly uniformly throughout the cytoplasm. By 30 months, pigment aggregations became very prominent cytoplasmic features of many nerve cells in the dorsal ganglia and cerebellum. A more detailed examination of neurons from the dorsal ganglia with the electron microscope revealed particles of variable size with a high electron density at four and 8 months. By 20 and 30 months, the pigment bodies appeared to be larger and were more concentrated near the nucleus. In Purkinje cells of the cerebellum the pigment granules were observed only rarely at four and eight months. By 20 and 30 months, the granules in the Purkinje cells appeared to be larger, considerably more numerous, and concentrated between the nucleus and the apical dendrite. The intracellular pigment concentration was also estimated by calculations of the per cent of area occupied by pigment granules as well as by the per cent of the cells that contained pigment bodies at 4, 8, 20 and 30 months. A progressive increase in the intracellular pigment concentration was readily noted.

ISSN:0003-276X    

DOI:10.1002/ar.1091600305

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

年代:1968

数据来源: WILEY

摘要:

AbstractThis experiment was designed to reveal the developing pattern of the ECG occurring in chick embryos during the period between 11 and 22 somites and to relate these findings to the appearance of blood circulation and the ability of the heart to exhibit atrioventricular block under the influence of digitalis. Using a unipolar electrode placed directly upon hearts of a graded series, the first recorded ECG was a simple V wave at 11 somites (sometimes 10) which increased in amplitude and rate through the 16 somite stage. In 16 or 17 somite embryos two deflections appeared on the descending limb of the V wave. In the light of subsequent changes these were recognized as the first indications of the P wave and QRS complex. Within an hour of development (17 to 18 somites) three events coincided, i.e., appearance of the primitive P wave and QRS complex; the beginning of blood circulation as evidenced by flow through extraembryonic capillaries; and the ability of the hearts to show a block at the AV junction. This last occurs despite the fact that an obvious PR interval is not present at 18 somites. However, from the 18 to the 21 to 22 somite stage rapid changes in the pattern of the ECG were recorded. The PR interval emerges; the P wave and QRS complex become incisive and are followed by an obvious T wave.The developmental pattern is the exact duplicate of the changes which can be recorded in reverse, by treating a single 60 hour embryonic heart with eserine (Paff, Boucek and Glander, '66) or apparently any acetylcholinesterase inhibitor (work in progress).

ISSN:0003-276X    

DOI:10.1002/ar.1091600306

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

年代:1968

数据来源: WILEY

摘要:

AbstractA group of 27 females and 24 males between the ages of eight years four months and 15 years seven months was examined to determine the vertebral level of their arytenoid cartilages. An apprasial of their lateral cephalometric radiographs which included the cervical vertebra was made under rigid conditions. Each cervical vertebra was divided into three sections in order to relate its position more precisely to the cartilages. The age of each subject was recorded and then compared with the vertebral level of their arytenoid cartilages. General consistency seemed to prevail throughout the group at given sex and age levels. Visualization of the arytenoid cartilages was excellent. No evidence of mineralization in the laryngeal cartilages was noted in the age group studied.

ISSN:0003-276X    

DOI:10.1002/ar.1091600307

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

年代:1968

数据来源: WILEY

摘要:

AbstractMethylene blue preparations and silver impregnated material were used to demonstrate the sensory nerve endings in the temporomandibular joint of the Rhesus monkey. Sixteen millimeter motion picture sequences of the various nerve endings were photographed while the microscope was slowly focused up and down through the entire thickness of the nerve ending. A 15‐minute film with descriptive sound track was prepared to demonstrate these nerve endings in three dimensions. The following types of nerve endings (listed in decreasing order of frequency) were seen in the articular capsule and peripheral portions of the articular disk: free, Ruffini, Golgi, and Paciniform endings. The sphenomandibular and stylomandibular ligaments in these monkeys gave no gross appearance of a ligamentous structure and did not contain any specialized proprioceptive nerve endings. Physiologic studies indicate that the nerve endings seen in the temporomandibular joint provide sensory mechanisms for the rception of pain, the autonomic control of vascular supply, and the recording of information concerning joint position and change in rate of movemen

ISSN:0003-276X    

DOI:10.1002/ar.1091600308

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

年代:1968

数据来源: WILEY

摘要:

AbstractThe influence on pituitary cytology of propylthiouracil (PTU) and estradiol benzoate (EB) administered singly and in combination was studied by electron microscopy in adult female rats. PTU alone induced striking changes in the morphology of thyrotroph cells, which were all transformed into typical thyroidectomy cells, characterized by enormously dilated ergastoplasmic sacs; the acidophils were degranulated and some of them took the appearance of relatively quiescent prolactin cells rather than degranulated somatotrophs. EB alone caused no definite changes in the morphology of thyrotroph cells; its essential effect was the development of a large number of prolactin cells. When both treatments were combined, thyroidectomy cells were found, existing side by side with untransformed thyrotrophs and exhibiting less dilated ergastoplasmic sacs than after PTU alone; prolactin cells were present in great number and showed a more developed ergastoplasm than after EB alone. Thyroid weight and height of the follicular cells were not changed by EB given singly; they were both increased under the influence of PTU; thyroid weight but not mean height of the follicular cells was slightly less increased when EB was added to PTU. It is tentatively concluded that estrogen may have a dual action on the thyro‐pituitary axis: on one hand, a depressing influence on thyrotroph cells and on the other hand a direct stimulatory effect on the thyroid glan

ISSN:0003-276X    

DOI:10.1002/ar.1091600309

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

年代:1968

数据来源: WILEY

摘要:

AbstractThe number of mitotic figures present at one time in regenerating mouse liver, 48 hours after injury with CCI4, was increased by administration of colchicine. The livers were injected with india ink at the time of sacrifice to outline the blood vessels, and histological sections were made. Microscopic examination supported by statistical studies indicated that mitotic figures do not occur at random at this time in regenerating mouse liver. The dividing cells were found in close proximity to the terminal twigs of the branch of the portal vein in zone one of the functional lobule described by Rappaport.

ISSN:0003-276X    

DOI:10.1002/ar.1091600310

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

年代:1968

数据来源: WILEY

摘要:

AbstractCells that took up tritiated thymidine (H‐3T) at various periods of intrauterine and early infant life in the periventricular proliferative zone and migrated to form the isocortex in the rat were tracked autoradiographically in series of stages to characterize their movements. Cells labeled at any stage soon separated themselves into cohorts, some continuing to proliferate, others migrating at once, and still others delaying before migrating. Migratory cells moved to the developing cortex along the curved and oblique paths of the pallial fibers, whose basic plan was established by the early thalamocortical fibers. Magnitude of speed was 15 to 30 μ per hour. The primitive neural cells that originated on each of the fourteenth to eighteenth intrauterine days first reached the cortex in about 48 hours, others took two or three days longer. Migrations originating on the nineteenth to twenty‐first days continued into the week after birth; as the primitive cells approached the cortex, however, they differentiated into young neurons, and traveled perpendicularly to its outer part. The first cohort of twentieth day labeled cells reached their intracortical destinations in about three days, the last in about ten days. The isocortex was formed essentially from within outward. The first neuroglia destined for the isocortex arose on the twenty‐first intrauteri

ISSN:0003-276X    

DOI:10.1002/ar.1091600311

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

年代:1968

数据来源: WILEY