• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1348
  • 865
  • 338
  • 338
  • 338
  • 338
  • 338
  • 337
  • 196
  • 80
  • 38
  • 37
  • 32
  • 17
  • 17
  • Tagged with
  • 4822
  • 1444
  • 1439
  • 1402
  • 1186
  • 832
  • 650
  • 585
  • 283
  • 283
  • 240
  • 228
  • 217
  • 202
  • 183
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
401

A clinically applied anatomical study of the coronary arteries in the South African population.

Lachman, Nirusha. January 2003 (has links)
Interest in the anatomy of the coronary arteries dates as far back as the early 1500's, at a time when anatomical inquiry was being cautiously aroused. Whilst the later 1700's encouraged academic domination of anatomical study, significant documentation of the coronary arteries was only been established by the late 1800's to early 1900's. There is no doubt that this topic continues to remain dynamic, favoured for its value in applied clinical research. Indeed, technological advancement in the 21 st century has transformed modem day anatomy into more than just a simple descriptive exercise. Whether to update standard literature, create ethnically specific banks of anatomical data, abate technical difficulties associated with coronary artery surgery or provide exciting interventional possibilities for clinicians, revisiting the anatomy of the coronary arteries is clearly warranted. The objective of this investigation was to review the anatomy of the coronary arteries using a clinical approach in order to investigate the morphologic presentation of these vessels within the South African population. On a more clinically universal level, this study aimed to elucidate two focal areas of anatomical interest: extra-cardiac collaterals and myocardial bridges. The investigation was conducted by means of micro-dissection, angiography, histology and scientific evaluation. A total of 323 sets of coronary arterial patterns consisting of patient angiograms (n=212) and cadaveric dissections (n=95) were studied. Specimens were harvested at post-mortem and angiograms and surgical reports were obtained from clinical centers within KwaZulu-Natal. Results of this study confIrmed the standard anatomical description of the coronary arteries as documented. Within the South African population, the ramus marginalis artery was found to be present in 13.3% (Females: 10.7%; Males: 5.6% and Blacks: 18.0%; Indians: 6.6%; Whites: 1.4%). The LAD and LCX arteries arose from independent aortic ostia in 14.5%, (Females: 7.5%; Males: 15% and Blacks: 6.5%; Indians 50%; Whites: 35%). Right dominance was observed most frequently in 85.9% (Blacks: 82.3%; Whites: 83.6% and Indians: 86.4% and Males: 82.6%; Females: 89.2%). A bifId LAD artery was noted in 52%, (Females: 6.2%; Males: 8.7% and Blacks: 17.6%; Indians: 6.3 %; Whites: 4.5 %). In 27.7%, (Females: 24.0%; Males: 28.8% and Blacks: 29.5%; Indians: ·50%; Whites: 20%) the LCX artery failed to continue along the atrioventricular groove. The conus artery arose from a high position off the RCA in 19.2%, (Females: 16%; Males: 21% and Blacks: 19.7%; Indians: 100%; Whites: 10%); and from an independent ostium in 3.61%, (Females: 4.0%; Males: 3.8% and Blacks: 4.9% only). The LCA measured 0.82cm (0.27-2.4cm), (Females: 0.84cm, Males: 0.96cm and Blacks: 0.88cm; Indians: 0.53 cm; Whites: 0.78cm). Myocardial bridges were recorded on the RCA in 2.5% and on the LAD in 50.6%. The bridge pattern depicted myocardial loops to complete arterial investment and ranged in length from 3.0 to 20.02 mm. Scientiftc evaluation of the intramural LAD indicated positive correlation between a straight appearance ofthe LAD on angiogram and a deep myocardial position upon surgical observation (mean "tortuosity index" = 1.147 [1.373-1.045] where 1= baseline for straightness). Results were confIrmed in the correlated cadaveric investigation. Extra-coronary collaterals were observed in 100% (n=9). The arterial pattern consisted of 1 to 2 main stems with secondary anastomotic branches. The average external diameter was measured to be 0.6mm (OA-0.7mm), length 52.5mm (1883mm) with at least 5 secondary branches (3-9) of external diameter O.3mm (0.20.5mm). Results of the histopathological investigation (n=20) indicated the presence of atherosclerotic disease within the intramural LAD artery segment (15%). A 60% incidence was recorded in the pre-mural segment and 25% incidence in the post-mural arterial segments. When analysed in terms of severity, the intramural segment reflected only mild signs of intimal alteration. Although not statistically significant, mean values for coronary artery size differed between sexes. The findings were similar when evaluated in terms of the coronary artery anomalies studied. There were signifIcant differences between ethnic groups in terms of the length of the LCA. Mean values showed that Indians had the shortest LCA's when compared with Blacks and Whites. The highest incidence of the ramus marginalis branch was recorded amongst Blacks. Separate origin of the LCX and LAD was highest amongst Indians and high in comparison to reports documented in other countries. A high origin ofthe conus artery was found to be dominant amongst Blacks. A low incidence of separate origin of the conus from the aorta was recorded in the South African population. These findings are significantly lower than that reported in the literature. A right dominant system has the highest occurrence within this population. Statistical evaluation confirmed that neither sex, ethnicity, age nor height influenced dominance in a coronary arterial pattern. The presence and description of the bifid LAD has been recorded. Its occurrence is highest amongst Blacks. The anomalous path of the LCX has been documented and described. The significantly high occurrence of this disposition of the LCX within the South African population appears to be the highest reported fmd in the literature. In terms of the presence and patterns of myocardial bridges, there are no observable differences between ethnic groups or sex. Results ofthis study confirm a relationship between the straight appearance of the LAD on angiogram and its anatomical presence. Extra coronary collaterals have been successfully investigated and observed. Measurements of vessel dimensions and patterns have been recorded. Results of the histopathological investigation illustrate that the intra-mural LAD artery is relatively protected from vascular disease. It does not however support the theory that in such a sub-myocardial position, the LAD artery is never prone to the damaging effects of atherosclerosis. The "cardio-protective" effect of a muscular bridge, whilst prevalent, is dependant on the thickness and extent ofthe bridge itself The anatomy ofthe coronary arteries has been successfully documented and a bank of data, specific for a South African population has been presented. Significant aspects of coronary arterial patterns have been discussed and interpreted in terms of its clinical relevance. This study presents an original method for the investigation of EeC's using technologically advanced materials and equipment. In addition, a scientific method for confirmation of a "straight" appearance of the LAD artery has been developed in this study. Findings contribute to the bank of diagnostic indicators that may be used to predict myocardial bridges pre-operatively. Through the dissection experience of more than 150 hearts and observation of more than 200 angiograms, this study has been able to contribute to the anatomical description o fthe coronary arteries. In some ways new perspectives were afforded and on the same note, already existing concepts have been verified. The value of this study IS enhanced by the potential clinical impact that such data is envisaged to create. / Thesis (Ph.D.)-University of Durban-Westville, 2003.
402

The anatomical study of the osteochondral, vascular and muscular relations of the superficial and deep cervical plexuses.

Pillay, Pathmavathie. January 2010 (has links)
In standard anatomical textbooks, the formation of the cervical plexus is well defined; however the accurate differentiation into superficial and deep plexuses, their emerging patterns, and gross anatomical relations are not documented as expansively. In order to obtain detailed anatomical knowledge of the superficial and deep cervical plexuses, the investigation aimed to clarify the anatomy and variations of these plexuses, define possible anatomical landmarks, and record the relationship of the external jugular vein and muscles of the posterior triangle of neck to the branches of the superficial cervical plexus, and the relationship of the common carotid artery, internal jugular vein, sympathetic chain, cervical verterbrae, and vertebral artery to the deep cervical plexus. The studies utilized the gross anatomical dissection, morphological and statistical analyses of forty fetal and fifteen adult cadaveric, formalinized specimens. The branches of the superficial cervical plexus emerged from the posterior border of the sternocleidomastoid muscle at the great auricular point (situated in the middle third of the muscle) and was described as ascending (lesser occipital, great auricular, transverse cervical nerves) and descending (supraclavicular nerves). Further, these branches were recorded according to their branching patterns, relations to the external jugular vein and variations. The branching patterns are described as single, duplicate and triplicate. The external jugular vein was constantly located inferior to the great auricular nerve, superior to the transverse cervical nerve and intertwined with the branches of the supraclavicular nerves. Variations of the branches of the superficial cervical plexus were observed only in fetuses and classified according to their course, branching patterns and communications. The emerging point of the branches of the superficial cervical plexus on the sternocleidomastoid muscle, were determined according to the seven types of “emerging pattern” classification by Kim et al., (2002). In order to record the deep cervical plexus, the sternocleidomastoid muscle was reflected with the following observation: the ventral rami of the second and third cervical nerves emerged between the scalenus anterior and scalenus medius muscles, and the third and fourth cervical nerves was located at the lateral edge of scalenus medius muscle. The deep cervical plexus was described as communicating, muscular, ansa cervicalis, and phrenic nerves. The superior cervical ganglion constantly communicated with the ventral rami of the cervical nerves; and the hypoglossal communicated with the superior root of the ansa cervicalis. The muscular branches were observed to the scalenus anterior and scalenus medius muscles with an anomalous branch to the sternocleidomastoid muscle. The ansa cervicalis demonstrated a degree of variation with regard to its origin, course and formation of the loops. The phrenic nerve arose from the ventral rami of the third, fourth and fifth cervical nerves and descended on the lateral border of the scalenus anterior muscle. The precise understanding of the anatomy of the superficial and deep cervical plexuses together with variations may assist anesthetists and surgeons to accurately identify the vascular, neural and muscular structures and reduce the risks of complications when performing neural blocks in regional anesthesia, facial rejuvenation surgery and parotidectomies. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Westville, 2010.
403

Clinical and pathological predictors of survival for stage II and III colon cancer patients treated with or without chemotherapy : a population-based study /

Morris, Melinda. January 2007 (has links)
Thesis (Ph.D.)--University of Western Australia, 2007.
404

The comparative histology of the esophagus and stomach of birds of different food habits

Lazareff, Anne Eileen January 1949 (has links)
A histological investigation was carried out on the esophagus and stomach of the following birds: kingfisher (Megacercyle alcyon caurina), California murre (Uria aalgae Californioa), screeoh owl (Otus asio kennicotti),Peale's faloon (Falco peregrinius pealei), and sparrow hawk (Falco sparverius sparverius). A number of stains was used to intensify the different structures present. In the kingfisher, murre and owl the esophagus was a thin walled highly expansible tube of generally even calibre, whereas in the Peak's falcon the anterior part was dilated into a sac. The wall of the esophagus possessed the usual structure characteristic of this region of the digestive tube. Three types of glands have been distinguished in these birds. In the kingfisher and owl simple oval glands were situated almost entirely within the epithelium. The glands and excretory duct were composed of similar cells with slight variations occuring in excretory duct lengths. In the California murre the glands were still simple but had sunken to the tunica propria with just the excretory ducts passing through the epithelium. The gland cells were narrower, and the duct cells resembled those observed in the owl and the kingfisher. These glands were all apocrine secretory. However, in the Peale’s falcon and sparrow hawk secretion was holocrine. These glands were deeply embedded within the tunica propria and resembled the esophageal glands of the chicken. The excretory ducts were lined by squamous epithial cells. Although the birds examined possessed a variety of food habits: fish, mammals, birds and crustaceans, the food was essentially meat. However, considerable variations in the structure of the esophagus were observed. The proventriculus was comprised of: a mucosa, indented with minute gastric pits, a muscularis externa of three layers of smooth muscle, and a lamina adventitia that surrounded the entire tube. Within the mucosa the deep glands were situated. These were composed of large lobes, enveloped in a dense capsule of connective tissue and internally consisted of simple tubules that radiated about a central excretory duct. The structure of the proventriculus was more or less uniform in the birds investigated, with only slight variations occuring in cellular arrangement and cellular size. The gizzards in the birds examined were large spherical structures that filled a majority of the abdominal cavity. In the kingfisher, owl, Peale's falcon, and sparrow hawk, the gizzard was lined by a thin keratinoid lining that was secreted by the glands present in the gizzard mucosa. The muscularis externa was of approximately equal thickness throughout. In the murre, the keratinoid layer was five or six times as thick as in the above birds and the muscles showed a heavy development on the dorsal and ventral sides. This development took place toward a grinding mechanism that was necessary for processing the hard shelled crustaceans eaten by this bird. / Science, Faculty of / Zoology, Department of / Graduate
405

The Impact of Student Motivation on Academic Performance in an Online Undergraduate Gross Anatomy Course

Parker, Madeline F. January 2022 (has links)
No description available.
406

Functional morphology of the hominoid shoulder, past and present

Berger, Lee Rogers 18 July 2016 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg 1994. / This thesis presents an :investigation into the functional morphology and form of the skeletal elements of" the shoulder girdle of extant h0111inoids and extinct hO)ll.inids\~hich inhabited the Afr:i.c~n continent during the Late pliocene and Elarly \Ii Ii \Ii, ill Partic'l.l.lcu: emphasis is placed o\~\the \' i\. form of the scapula, clavicle and humerus. \Ii variation in the bony, arthrological and 41.yoloQif\;Lcal I" anatomy' Of this region in extant hominoids is I Pleistocene. examined. In light of biomechaniq~l models II reSUlting from this work, the bony,;anatomy of u hominid shoulder girdle elements examined and i. .1 r;:I~t>. ssil .1,1 . " biomechanical interpretations are made. The fossil shoulder girdle elements exan\ine~ in this study are grouped into four species samples. The first sample (Australopithecus a.:friCaIlUS) comprises Pliocene ,fossils from sterkfontein, South Africa. 'rhe second sampJ.e (A. afarelJ.si.s) i.s comprised of fossilo front Hadar, Ethiopia. The third (Homo habilis) and, fourth (ii. boisei) samples comprise fossils from C'lduvai GorgeI Ta:nzania, Koobi For~ll, Ke!nya and t.ne omo Valley ~ Ethiopia. When the t!;ossil homi.ndd. remains are scrt.ed into specf.ea, jl~heI:;houlder g;l.rdle elements InelYd:>e used to const.zuct; and contrast specd.es specijSiq '1· . ) bitOmechar1,ic::aml odelS of th~ shoulder. Th~~se models e:>fltP10re differernoes in form amon~,r.;tj;ossil hominid. species that may'be reJ,ated to dii.:;eetenc;:.es in behaviour. The models may also be appU.ed to the :~......,..~ interpretation of systemat.ic relationShips amongst early hominids. In o:(.~ierto construct models of early homi:p,ids it is first necessary to establish the,movement, myology and oste0logy of the extant hominoid shoulder. Chapters 4,5 and 6 sUl'l.1Il1ar~n,$eew data and available in,formation concel:"ning shoulder girdle mo.Jementand form. Chapter 7 presents detailed C';escriptiQns Of the fossil hominid ma.terial (u:::::19) available for study. 'rhis descriptive information, in conibination with all of the information derived from Chapters 4 through 6, is then used to inte1.pret, compaxe and contrast the fu.nctional morphology Of the shoulder girdle elements of each species of early hotninid. pa:q:ticuJ.ar emphasis is placed .on those features that cart be. directly related to specific :functiOl'l~ Model.s ,,.l the functional morphology of each of t1Je four species are then created. comparisons are made between indJ.vidual Shoulder girdle elements 'cg,fthe different homj.nid spacd.es as well as between the interpreted total morphology of each species' shoulder girdle. The study concludes that the functional m~>l':phologyof the shoulder girdle Qf A. afriaanus is unique ~unorJ.gstknown hominoic1~mode'l.s in that it poasesaes shoul<;ier girdle mo;t,'ph.oo.)gy adapted to bobh suspen ory behaviour and bipE~d;;d~i.srn. TIte suspensory adaptations are :Lndi9ated by the overall ape ..like morphology of the humeri, claviculae and heCid.of the scapulae, whilst bipedalism is mainly (J G indicated. by a broad, human-like inf.Ell:'ior'an9,'].eof " = the scapula. Several' RpparentlY prim.itive featu:r:es" are present in,..the A. africanus Ejcapl,1la,incl~dirtg a 0i,? ..... . _ .. '. \ shortened scapular 'n~ck, that ind:l.Cate'-\poss~ple ancestry f.roma quadru:pedal form. ~p.e functi<:>tJ.al. morphology of the A. afarens.ts shoulder is founa .to be more diffi.cult to interpret d'.le to poor f(i:; ,pre.~ervationt but the hypothesised znodel'~does not diffe):: substantially from th~t constructed for A. _c,~) . ..' .', 1) (; a£ricanus. The few robust aURtra.lopithecine,.,(A. boi.se:1) sho~~der girdle elements appear to possess ~,.. similar morpJ;lologi.esto A. a.:falyrnsis and )1- africanus. There ara .no'l:.SUfi:'lc:tently well preServedoH. habili.s shoulder girdle elements preserved to 'makemeffilningfulinterpreta.tions about the functional morphology of this, specie~:' .' n the lack of comparable elements amongst the two (I 1arger samples (...21.. a:faJ;'ensi.s and ,fl. arr:J;canus) I .it '..':::/ is not knownwhether the features found to be apparently unique to either species are useful as n taxonomic indicators.
407

Encapsulated nerve endings in the digital pads and planum nasale of dogs and cats

Reddy, Venkat Krishna. January 1961 (has links)
Call number: LD2668 .T4 1961 R43
408

Origin and early development of the canine circumanal glands

Isitor, Godwin Nwachukwu. January 1978 (has links)
Call number: LD2668 .T4 1978 I83 / Master of Science
409

Quantitation of Teratogenic Effects of 5-fluorouracil Administered to Mice in Vivo or in Submerged Limb Culture

Sanders, Theresa A. 01 May 1987 (has links)
This study demonstrates the use of submerged limb culture in teratologic testing. Pregnant mice were treated on day 11 of gestation (E11, plug date = E0) with 10, 20 or 40 mg of 5-fluorouracil (FU) per kg body weight. On E17, treated and untreated fetuses were examined for gross malformations and were fixed in 95% ethanol. Reduction of limb size and digital defects, including ectrodactyly (ED), syndactyly (SD), microdactyly and polydactyly were dose-dependent. In parallel studies, pregnant mice were treated on the morning of E11 and embryos were removed either 7h (E11) or 24h (E12) later for submerged limb culture. Changes in limb area showed a dose-response relationship while treatment had little effect on the shape of individual bones. This indicates the relatively unspecific nature of FU-induced embryotoxicity. E11 studies revealed a dose dependent response of ED, SD and fusion of the metacarpals/metatarsals (MC/MT) to the proximal phalanges. Unlike E11 cultures, middle phalanges were present but decreased in number as dosage increased. Limbs from embryos of untreated females were cultured (E11) in the presence of 0.002, 0.02, 0.2 or 2.0 mg FU/ml culture medium. The percentage of limbs void of paw cartilage or with decreased numbers of MC/MT was dose-dependent. A dose-dependent decrease in the deleterious effects of 0.02 mg FU/ml was observed when 0.2 or 0.02 mg thymine/ml was added to the cultures. In both culture and non-culture studies, hindlimbs (HL) were more affected than forelimbs (FL) and distal regions were more affected than proximal ones. In addition to the morphometric analyses, biochemical parameters of growth and differentiation were examined at 0, 36 and 72h of culture in untreated and treated limbs. Both DNA and protein of FU treated limbs were decreased compared to untreated controls. FL demonstrated greater capacity for regulation of losses in protein content, HL for DNA content. Submerged limb culture provides a useful model for the examination of xenobiotic effects on limb development and allows some comparative evaluation among in vivo, in vivo/in vitro and in vitro studies. (Abstract shortened with permission of author.)
410

The gross and microscopic renal anatomy of the fish eating bat, Pizonyx vivesi

Braun, Eldon J. January 1965 (has links)
No description available.

Page generated in 0.0563 seconds