摘要:

AbstractEach of the major cardiac valves (two arterial and two atrioventricular) is made up of a fibrous annulus with a characteristic configuration, and cusps or leaflets comprising a layer of endocardium folded over a fibrous lamina. Each of the arterial valves (aortic and pulmonary) has an annulus shaped like a three‐pronged coronet to which are attached three equal‐sized semilunar cusps. The arterial wall beyond each cusp forms a pocket or sinus which is crucial in the efficient closure of these valves. The coronary arterial orifices in the aorta lie high in two of the sinuses or above them and are unaffected by valve action. Narrowing of the annulus is a significant component of closure of each cardiac valve, more so for the atrioventricular valves than the arterial. Despite their traditional terminology, the left and right atrioventricular valves (mitral and tricuspid) both possess more than three leaflets each. Closure of these valves is not dependent on the number of leaflets and it is easiest to regard leaflet tissue as a continuous veil or skirt tapering towards the ventricles, where it is tethered to papillary muscles by means of chordae tendineae. Closure of these valves is biphasic, an incomplete phase in late diastole and complete closure during ventricular systole. Movement of atrioventricular leaflet tissue is slight as it is held down by tension of the chordae tendineae. © 1993 Wiley‐Lis

ISSN:0897-3806    

DOI:10.1002/ca.980060602

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

年代:1993

数据来源: WILEY

摘要:

AbstractA group of cadaveric livers bearing anteroposterior grooves or furrows in the superior surface of the right lobe is described. Such grooves have been noted by others in living patients. The existence of these grooves has been recognized since at least 1888, but there seems to be no agreement as to their cause. It appears from this study that different types of groove or indentation occur, according to their orientation relative to the median plane of the body. Two major groups of theories of causation are recognized, but no firm conclusions are drawn. © 1993 Wiley‐Liss, I

ISSN:0897-3806    

DOI:10.1002/ca.980060603

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

年代:1993

数据来源: WILEY

摘要:

AbstractTracheostomy surgery may be accompanied by complications that lead to morbidity and mortality. The incidence of these complications is not inconsiderable, as documented by case reports that continue to appear annually. Most complications are based on failure to appreciate the anatomic relationships of the area. In an operation that often falls to the lot of the junior surgeon and that deals with normal anatomic structures, it is disappointing to find that the surgeon gets little help when consulting clinical anatomic texts. Infact, the advice given may be erroneous, indefinite, or even misleading. It is strongly urged that a tracheostomy education program be instituted at the clinical anatomic level. © 1993 Wiley‐Liss, I

ISSN:0897-3806    

DOI:10.1002/ca.980060604

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

年代:1993

数据来源: WILEY

摘要:

AbstractIn this paper, we introduce the concept of functional anteversion of the femur and its positional change. It emerged from studies using B‐mode and real‐time ultrasound to determine femoral anteversion in two knee positions. Twenty healthy children were scanned at the hips whilst lying supine with knees extended and then with the knees flexed to about 90°. The “anteversion” angle between the head‐trochanter line and the horizontal measured with knees extended and feet together is determined by three factors: 1) anatomical femoral anteversion, 2) femoro‐tibial rotation at the knee, and 3) tibial torsion. This is one type of “functional anteversion” of the femur.The best reproducibility for functional femoral anteversion was obtained by scanning with real‐time ultrasound and the knees extended (95% confidence limits within ± 2.8°); the use of B‐mode ultrasound in the knees‐extended position is significantly less reproducible (95% confidence limits within ± 6.1°). In the flexed‐knee position, the reproducibility is similar with both B‐mode and real‐time ultrasound (± 2.6–3.5°). Both positions have limitations in attempts to measure anatomical femoral anteversion by ultrasound.The functional femoral anteversion angle measured by B‐mode and real‐time ultrasound is significantly larger (by 9–10°) with the knees flexed than with the knees extended. This positional change of measured femoral anteversion involving axial rotation at the hip is attributed mainly to 1) lateral rotation (unlocking) of the femur at the knee during flexion from the fully extended position and 2) any lateral tibial torsion which rotates the femur nedially in the knees‐extended position with the feet vertical. The considerable individual variation and asymmetry of this axial rotational change may have relevance to the etiology of certain clinical disorders of the spine,

ISSN:0897-3806    

DOI:10.1002/ca.980060605

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis report describes the length of the entire vena cava in Japanese subjects. This length is important for the use of the new intravenous oxygenator (IVOX). The IVOX is used as an intravascular artificial lung. Situated in the vena caval system, IVOX extends from the upper end of the superior vena cava via the right atrium to the lower end of the inferior vena cava. It was first reported by Mortensen (1987) and has been used clinically in the United States and Europe. The IVOX has four sizes, which range in length from 30 to 40 cm. When using the IVOX for Japanese subjects, a vena cava size that accommodates the IVOX should be chosen. We measured the length of the entire vena cava in 34 cases at postmortem examination. These lengths varied from 30 to 46 em. The calculated average caval distance was 37 cm with a standard deviation of ± 4 cm. Among three corporal indexes of weight, height, and body surface area, the most significant statistical correlation was between vena cava length and patient height. The regression equation for this is as follows: Y = −13. 0 + 0. 31 × X, where Y is predicted length of the vena cava (cm), and X is patient height (cm). This finding should serve as a relatively simple means for calculating the length of the entire vena cava, and it should be useful in clinical practice with the IVOX in Japan. © 1993 Wiley‐Lis

ISSN:0897-3806    

DOI:10.1002/ca.980060606

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

年代:1993

数据来源: WILEY

摘要:

AbstractWe describe a rare anomaly in the submental region of a single male cadaver specimen. The anterior belly of the right digastric muscle was observed to have three separate insertions. Most medial of these crossed the midline and inserted to the digastric fossa with the opposite digastric muscle. These muscle bands were united in a common tendon as they continued with the posterior belly. This is an anatomical variation in the mylohyoid digastric muscle group in the floor of the mouth. Consideration of such variations of the anterior bellies of the digastric muscles should be noted during the evaluation of the floor of the mouth in the CT examination or MR imaging. © 1993 Wiley‐Liss, I

ISSN:0897-3806    

DOI:10.1002/ca.980060607

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe gubernaculum has been described as the “rudder” that guides the testis into the scrotum. Prior to inguinoscrotal testicular descent, the gubernaculum rests in the groin and does not attach to the scrotum. Subsequently, it migrates and attaches to the scrotum under control of the genitofemoral nerve. This study evaluates, with electron microscopy, the relationship of the gubernaculum with the developing scrotum during normal testicular descent.Male rats were sacrificed at 0, 2, 4, 7, 10, 14, and 18 days (n = 2 for each group) and sagittal sections through the gubernacular‐scrotal interface evaluated with transmission electron microscopy. We observed the following with increasing animal age: (1) gubernacular cremaster muscle matured and nuclei shifted to the periphery of cells as connective tissue surrounding myofibers decreased, (2) scrotal fibroblasts initially showed high activity with dilated endoplasmic reticulum, but activity and number subsequently decreased, (3) scrotal collagen increased and organized into defined fibers and bundles, (4) a well‐delineated band of collagen developed along the gubernaculum and advanced towards the inferior scrotum, and (5) nerve fibers appeared between the layers of cremaster muscle, increased in number with increasing age, and became myelinated at age 14 days. Gubernacular migration is intimately associated with scrotal development and testicular descent. Knowledge of cellular and intracellular differentiation during migration in the normal animal can further understanding of abnormal development and lead to improvements in treatment for common surgical problems such as cryptorchidism. © 1993 Wiley

ISSN:0897-3806    

DOI:10.1002/ca.980060608

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe history of the production of a textbook of human anatomy is recounted. The objective was to compose a volume that would (1) be regional rather than systemic in organization, (2) be a concise guide for both medical and dental students, and stress points of clinical importance, (3) be clearly illustrated but not be a substitute for an atlas, (4) include excellent radiographs and examples of other methods of imaging, (5) use the (then new) internationally accepted nomenclature, but provide a glossary of eponymous terms, and (6) treat the subject as a university discipline with its own history and encompassing an appropriate literature, including both strictly anatomical and clinically applied references. It should be remembered that at that time, more than 30 years ago, these notions were not nearly as frequently encountered in practice as they might be today, although even now it would be difficult to find a textbook in which all of the above features are combined. © 1993 Wiley‐Liss, I

ISSN:0897-3806    

DOI:10.1002/ca.980060609

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

年代:1993

数据来源: WILEY

ISSN:0897-3806    

DOI:10.1002/ca.980060610

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

年代:1993

数据来源: WILEY

ISSN:0897-3806    

DOI:10.1002/ca.980060611

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

年代:1993

数据来源: WILEY