Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Anatomists”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources
PubMed1990

Irregular geometries in normal unmyelinated axons: a 3D serial EM analysis.

Axons have generally been represented as straight cylinders. It is not at all uncommon for anatomists to take single cross-sections of an axonal bundle, and from the axonal diameter compute expected conduction velocities. This assumes that each cross-section represents a slice through a perfect cylinder. We have examined the three-dimensional geometry of 98 central and peripheral unmyelinated axons, using computer-assisted serial electron microscopy. These reconstructions reveal that virtually all unmyelinated axons have highly irregular axial shapes consisting of periodic varicosities. The varicosities were, without exception, filled with membranous organelles frequently including mitochondria, and have obligatory volumes similar to that described in other neurites. The mitochondria make contact with microtubules, while the other membraneous organelles were frequently found free floating in the cytoplasm. We conclude that unmyelinated axons are fundamentally varicose structures created by the presence of organelles, and that an axon's calibre is dynamic in both space and time. These irregular axonal geometries raise serious doubts about standard two dimensional morphometric analysis and suggest that electrical properties may be more heterogeneous than expected from single section data. These results also suggest that the total number of microtubules contained in an axon, rather than its single section diameter, may prove to be a more accurate predictor of properties such as conduction velocity. Finally, these results offer an explanation for a number of pathological changes that have been described in unmyelinated axons.

Animals↗
PubMedDate not supplied

Treitz redux: the ligament of Treitz revisited.

In the medical literature, the ligament of Treitz is frequently used as a term to designate the duodenojejunal flexure, but the attributes of the structure itself are not generally known. Indeed, anatomists describe it as the suspensory muscle of the duodenum, arising from the connective tissue around the stems of the celiac and superior mesenteric arteries and inserting as nonstriated muscle commonly into the third and fourth portions of the duodenum and frequently into the duodenojejunal flexure as well. Misconceptions regarding its configuration and anatomic relationships continue to be widely illustrated. The fibromuscular structure plays an important role in the embryologic rotation of the bowel and in facilitating normal progression of contents from the extraperitoneal duodenum to the mesenteric small bowel and contributes to the effects of the superior mesenteric artery syndrome. Whereas virtually all other ligaments and mesenteries in the abdomen have been imaged, features of the ligament of Treitz render its visualization by CT or MRI challenging.

Duodenum↗
PubMed1987

Comparative anatomy of cutaneous muscles of the face.

Comparative anatomical studies of monkeys, apes, and humans have clarified essential factors involved in the structure of the cutaneous muscles of the face. Among the findings are that the platysma muscle is a very important entity because it is the only muscle without any bony attachments. In addition, the platysma is a fan-shaped structure that has been divided artificially by classical anatomists into five elements. The parotid fascia forms part of this fan-shaped fibromuscular structure and is not of the deep fascia. As such, these findings require a revision of the classical anatomical concepts of the parotid space.

Adult↗
PubMed1995

The arterial blood supply of the pancreas: a review. I. The superior pancreaticoduodenal and the anterior superior pancreaticoduodenal arteries. An anatomical and radiological study.

The gross anatomy of the pancreatic blood supply has been subjected to numerous studies. The results of such studies, however, have never been summarized in detail, even in the most important textbooks. For this reason, a certain confusion was generated, especially regarding the interpretation of the nomenclature used to identify pancreatic arteries. This review summarizes more than two centuries of studies of the gross anatomy of the pancreatic blood supply, clarifies the arterial nomenclature, and underlines the aspects about which anatomists are not in agreement. Moreover, it supplies, as far as possible, documentary evidence for numerous observations previously reported only verbally. For this purpose, more than 200 references were directly consulted to provide the anatomical background of the topic, and more than 1000 angiograms were studied to support the review with original figures. The present paper, on the superior pancreaticoduodenal and anterior superior pancreaticoduodenal arteries, is the first of a series of articles dealing with the pancreatic blood supply.

Aorta, Abdominal↗
PubMed1993

Reflections and suggestions on the nomenclature of the prostate.

The prostate has been given different and contradictory nomenclatures. The nomenclature of the normal prostatic gland must allow for the concepts of comparative anatomy, human anatomy and pathologic anatomy. The object of this study, based on a review of the literature, is to analyse the discordant terminologies, which give rise to misunderstandings, and to suggest a simple nomenclature conformant to anatomic rules and the descriptions of leading authors. It seems necessary to suggest a schema utilising the studies of comparative anatomists and the original descriptions of Albarran and correlating all this information. One must distinguish between the prostate, the prostatic gland and the periprostatic fibromuscular tissue. The central glands are those situated at the center of the prostate in the urethral wall. The prostatic glands themselves are found around the urethra. Within these glands there is a distinction between the cranial glands situated around the ejaculatory ducts, which drain above the seminal colliculus, and the caudal glands situated below the ejaculatory ducts which drain into the urethra below the colliculus. Between the wall of the urethra which contains the central glands and the peripheral glands is the transitional zone.

Animals↗
PubMed1997

Penile arteries in humans. Origin--distribution--variations.

The arterial supply to the penis remains unclear. The frequency of occurrence and functional significance of accessory pudendal arteries remains controversial and it has been suggested that the presence of variations is correlated with atheromatous disease involving internal pudendal arteries. We dissected pelvic and penile arteries in 20 adult fresh male cadavers. The results are expressed according to age and the presence of atherosclerosis. Three patterns of penile arterial supply can be described: type I arising exclusively from internal pudendal arteries (3/20), type II arising from both accessory and internal pudendal arteries (14/20) and type III arising exclusively from accessory pudendal arteries (3/20). This study emphasizes the findings previously reported by early anatomists. No correlation between the presence of accessory pudendal arteries and the extent of atheroclerosis was observed. Accordingly we postulate that these variations are usually congenital. Terminal branches of accessory pudendal arteries mainly supply the corpora cavernosa. As they are located very close to the prostate, the risk of injury is high during radical prostatectomy. The possibility of impotence from such injury after radical prostatectomy needs therefore to be reconsidered.

Aged↗
PubMed1999

The Graz learning and training model for arthroscopic surgery.

Up to 30% of all operative procedures in orthopaedic surgery are performed arthroscopically. Because of the steadily increasing number of residents, it seems to be difficult both to maintain high standards and to guarantee an adequate training in arthroscopic surgery. However, in contrast to many other surgical techniques it is possible to learn and practice arthroscopy using artificial models and cadaver joints, provided that experienced surgeons and anatomists act as supervisors and instructors. The aim of this paper is to assess practice models and training programs which should guarantee sufficient practical experience during the training period.

Arthroscopy↗
PubMed1997

Fascia: an illustrative problem in international terminology.

As a result of international nomenclatures being in Latin, with the terms usually being undefined and translated into national vernacular languages, the same terms have been used in different ways in different countries. Fascia is an example of this, the limits of the meaning of the word differing in English-, French- and German-speaking countries. These differences are itemized in a comparative table. In 1989 the General Assembly of the International Federation of Associations of Anatomists [IFAA] created the Federative Committee on Anatomical Terminology [FCAT] with a remit to create a new terminology for the anatomical sciences with full democratic consultation with the member societies of IFAA. The draft recommendations of FCAT on fascia and the reasons for them are given. Problems associated with the use, or lack of use, of international terminologies are illustrated. For the advancement of medical knowledge and understanding, the cooperation of authors, editors and publishers in using the current terminology in the right way remains of critical importance. It is suggested that, after adopting a terminology, IFAA has a responsibility to arrange for technical back-up.

Fascia↗
PubMedDate not supplied

Surgical anatomy of the inguinal area.

The anatomy of the inguinal region is enigmatic and confusing. Among the many structures involved in hernial repair are the iliopubic tract, the transversus abdominis aponeurosis and the transversalis fascia, the transversalis crura and sling, and the inguinal canal. There is still much disagreement among surgeons and anatomists about the existence, structure, and function of these anatomic entities.

Anatomy, Artistic↗
PubMed1987

Some little-known aspects of spinal cord softening.

311 cases of spinal cord softening, were selected for review. The following points emerged from this study: 1) spinal cord softening is a rare occurrence; 2) while formerly syphilis was the most frequent cause, recently reports of cases secondary to aortic disease or to embolism with diffuse signs of arteriosclerosis and circulatory failure pointing to a different pathogenesis have become more frequent; 3) the site of softening rarely corresponds to the vascular spinal territories as defined by the anatomists, from which it may be argued that often several arterial territories may be involved simultaneously or, alternatively, that the arterial territories are not so rigidly defined as anatomical research has led us to suppose; 4) the few cases of multiple vascular lesions show that, as happens in the brain, the cord may be damaged contemporaneously or successively in several areas.

Adolescent↗
PubMed1997

The Origin of Species, Man's Place in Nature and the naming of the calcarine sulcus.

In The Origin of Species by Means of Natural Selection of 1859, Charles Darwin provided a detailed, coherent proposal: species changed into new ones by the action over time of natural forces in the environment acting continuously on the variations always present within species. Readers immediately extrapolated Darwin's argument concerning lower animals to the implications for humans, and its denial of a special creation of humans. In opposition to Darwin's theory, Britain's preeminent paleontologist and comparative anatomist, Richard Owen, argued that man was unique among all creation in the possession of a particular structure within the brain, the 'Hippocampus minor'. Darwin's great defender, Thomas Huxley, demonstrated that this structure also existed in monkeys and apes, and that it was simply a manifestation of a 'particular sulcus' in the posterior cerebral cortex, which he named as the 'calcarine' sulcus. The home of the visual striate cortex was thus named as part of the controversy surrounding the birth of evolutionary theory, soon to be accepted as the great unifying concept in all of biology.

Biological Evolution↗
PubMedDate not supplied

Walking on water: the biomechanics of Michael A. MacConaill (1902-1987).

Biomechanics is a subject that draws on knowledge from many disciplines. One of its great practitioners in the last century was the Irish anatomist M.A. MacConaill. In this paper, we review some of MacConaill's fundamental contributions to biomechanics, namely: the hydrodynamic theory of synovial joint lubrication, the kinematics of joint motion and conjunct rotations; and the theory of spurt and shunt muscles. The aim is to revisit these topics in the light of current research, and to draw some conclusions about the import of his research in the context of recent developments in the field. The paper concludes with a discussion of science in Ireland, the development of the field of biomechanics since MacConaill's time, and some other matters.

Biomechanical Phenomena↗
PubMed2005

Historical milestones in endocrinology.

The 1865 volume of the "II Morgagni", one of the most important Italian medical journals of the 19th century, presented two important articles, milestones for further scientific studies in the field of sexual differentiation. One was the original description of the "ramified cells" of testicular tubules by E. Sertoli, known today as Sertoli cells. The other was the first report and description of a patient with ambiguous genitalia, huge hyperplastic adrenal glands and salt-wasting symptoms: a true case of congenital adrenal hyperplasia, a disease well delineated only 80 yr later. Sertoli, although young (22 yr old) and inexperienced, was absolutely sure of his observation, also against the opinion of other important anatomists. He described different ways of presentation of these cells, hypothesized on their supportive and nutritive functions, but not on any endocrine function at that time. The second article was written by L. De Crecchio, a Professor of Forensic Medicine, and was the detailed description of the clinical, psychological and autoptic features of a female patient with severe ambiguous genitalia, who today would be diagnosed as having congenital adrenal hyperplasia probably due to 21-hydroxylase deficiency. This article gives, still today, important news on the clinical, psychological and social outcome of these patients before the possibility of therapy.

Adrenal Hyperplasia, Congenital↗
PubMed2001

[Surgical procedures in mouth, jaw and facial surgery in Thiel embalmed body donors].

METHODS: This study investigates whether human cadavers embalmed according to Thiel can be used for research and education in oral-maxillo-facial surgery. Different surgical approaches were tested on such cadavers. The usability of the specimen was judged jointly by anatomists and surgeons. Color, structure, and consistency of the different tissues were comparable to vital conditions. Thiel's embalming technique applied to human cadavers provides an optimal basis for research and for basic and postgraduate medical education.

Curriculum↗
PubMed1997

[Max Brödel (1870-1941): his life and contribution to the development of modern surgery].

Max Brödel (1870-1941), from Leipzig, Germany, is often referred to in the USA as the father of modern medical illustration and mentioned in the same breath as Leonardo da Vinci or Andreas Vesal. After a classical formal art education in Leipzig he worked in Carl Ludwig's laboratory of physiology and anatomy, where he came in contact with American physicians. In 1894, the anatomist F.P. Mall convinced him to work for the recently inaugurated Johns Hopkins School of Medicine in Baltimore, where he collaborated with world-famous surgeons such as H.A. Kelly, W.S. Halsted, and H. Cushing. His illustrations were characterized by meticulous observation, both realistic and explanatory intention, technical superiority, and artistic merit. In 1911 he established the first "Department of Art as applied to Medicine". Here, he proved to be an innovative artist, a creative scientist, and an inspiring and skillful instructor. By the time of Brödel's retirement in 1939, 160 students had graduated as medical illustrators. His pupils spread his principles and style throughout the USA and Canada, and several similar academic programs for medical illustration have been founded in these countries.

Anatomy, Artistic↗
PubMed2005

[Diprosopus triophthalmus. From ancient terracotta sculptures to spiral computer tomographic reconstruction].

A still-born male fetus from the 19th century, fixed in formalin and presenting as diprosopia triophthalmica, was analysed by helical computer tomography and virtually reconstructed without damage. This rare, incomplete, symmetrical duplication of the face on a single head with three eyes, two noses and two mouths develops in the first 3 weeks of gestation and is a subset of the category of conjoined twins with unknown underlying etiology. Spiral computer tomography of fixed tissue demonstrated in the more than 100 year old specimen that virtual reconstruction can be performed in nearly the same way as in patients (contrast medium application not possible). The radiological reconstruction of the Munich fetus, here confined to head and neck data, is the basis for comparison with a number of imaging procedures of the last 3000 years. Starting with some Neolithic Mesoamerican ceramics, the "Pretty Ladies of Tlatilco", diprosopia triophthalmica was also depicted on engravings of the 16th and 17th century A.D. by artists as well as by the anatomist Soemmering and his engraver Berndt in the 18th century. Our modern spiral computer tomography confirms the ability of our ancestors to depict diprosopia triophthalmica in paintings and sculptures with a high level of natural precision.

Craniofacial Abnormalities↗
PubMed2001

The internal calcar septum (femoral thigh spur) in computed tomography and conventional radiography.

OBJECTIVE: The femoral "thigh spur", a cortical septum in the region of the lesser trochanter of the human femur, was first described and named by the German anatomist Merkel in 1874, but it was never examined in detail. To evaluate the frequency and the shape of this structure, a combined anatomical and radiological study was performed using saw-cuts from specimens, high-resolution CT and conventional radiography. DESIGN: Thirty human cadaveric femora of central European origin were analyzed by high-precision computed tomography (CT) using thin slices and high-resolution imaging. The CT data were image processed with thresholding to obtain a reconstruction of high-density bone formations and for three-dimensional imaging. Additionally three macerated femur specimens were cut exactly corresponding to the CT slices. The computed images were validated with the anatomical saw-cuts. RESULTS: A dense trabecular ridge protruding endosteally from the posteromedial cortex was found in all femora. This cortical septum reaching from the femoral neck to the distal part of the lesser trochanter separated the femoral cavity from the cancellous bone inside the lesser trochanter. On conventional radiography the femoral thigh spur could be visualized best in the frog-lateral view of the hip. CONCLUSION: The internal calcar septum is a constant cortical structure. It should be recognized when radiographs or CT images of the proximal femur are interpreted. It could be of importance for metaphyseal fitting of an endoprosthetic stem.

Aged↗
PubMed2002

The seated man: geometry acquisition and three-dimensional reconstruction.

A three-dimensional (3D) virtual human body in seated position can be used in a wide range of applications such as basic or clinical research. A male cadaver placed in the driving position in a car cockpit was frozen. Strictly parallel 5 mm thickness serial sections were then performed. Both sides of the slices were photographed, scanned and analyzed by anatomists with software tools, in order to produce accurate contours of the identified anatomical structures. A 3D reconstruction of organs, based on the marching cubes method, was achieved except for thin structures. This allowed an anatomical validation of these reconstructed elements. The result of this work is a complete geometrical database of a seated human body in the driving position including skin, all bones, internal organs and main muscle groups.

Aged↗