ABSTRACT
Based on standard histological methods and specific injection technique, the study demonstrates for the first time the blood vessel system of the scrotal integument.The latter is relatively thin and shows a thick underlying fascia, the tunica dartos. The vessel networks found in both structures are somewhat different from each other, i.e., the former displays the typical integumental vessel scheme, which, because of its thinness, shows a higher vessel density. The tunica dartos displayed a blood vessel system with specific characteristics, i.e. horizontal networks are present, which are on the one hand directly connected to the rete dermidis and on the other hand, with the ascending (arteries) or descending (venes) vessels of the dartos, so that a rather uniform distribution and nutrition of the latter, including its muscle layers, is assured.The findings support the idea that the functions of the scrotal integument and the dartos are based on a dependable energy supply, but with regard to vessel type, particularly arteries, may also be involved in the regulation of blood flow. Thus, the scrotal integument as well as the dartos can be used for thermoregulation.
Subject(s)
Cattle/anatomy & histology , Scrotum/blood supply , Skin/blood supply , Animals , MaleABSTRACT
OBJECTIVE: New teaching methods such as e-learning, are increasingly used to support common methods such as lectures, seminars and practical training in universities providing education in veterinary medicine. In the current study, the acceptance of e-learning in the example of the CASUS system by veterinarians as well as students of veterinary medicine of all German-speaking universities was analyzed. Material und methods: For this purpose an online evaluation questionnaire was developed. Members of the target groups were informed by e-mail and references in professional journals, as well as through veterinarian exchange platforms on the internet. Additionally, 224 students' final anatomy marks were compared and correlated to the utilization of CASUS to gain an important insight for the development of new teaching practices in the teaching of veterinary medicine. RESULTS: In total 1581 questionnaires were evaluated. A good acceptance regarding new teaching practices was found, although the classical textbook is still the most important instrument for imparting knowledge. The degree of utilization of e-learning strongly depends on its integration into the teaching content. CASUS is regarded as an efficient teaching method, with over 90% of the respondents indicating a strong desire to expand the number of case studies. Due to the present low degree of integration into the teaching content, no significant correlation could be found between the utilization of anatomy case studies and the final anatomy mark. However, based on their subjective perception, the students reported a high level of success in their study results with the likely effect of supporting increasing self-assurance in the situation of examinations. CONCLUSION: With the help of e-learning, educational objectives can be achieved that are not attainable by traditional teaching methods, e.g. the review of individual improvements by using the integrated feedback-function of e-learning programs. However, e-learning is not able to completely replace current teaching practices and hence should be considered as an additional element in future teaching models.
ABSTRACT
Platelet-activating factor (PAF) and its receptors are involved in inflammatory-like processes of the uterus associated with increased vascular permeability. PAF is supposed to be influenced by ovarian steroid hormones. The present study was undertaken to examine whether progesterone (P(4)), estradiol (E(2)) or PAF influence the PAF receptor gene expression in perfused endometrial explants derived from ovariectomized bovine. Furthermore, we identified the cell types in which the PAF receptor gene and protein are expressed. In endometrial explants, applications of 10 nM P(4) or 10nM P(4) plus 10 nM E(2) for 24 h induced elevated transcript levels of PAF receptor in comparison to the controls or after treatment with 1 nM E(2). When explants were administered 10 nM E(2), a slight decrease in the transcript level was recorded. After treatment of explants with PAF, no significant changes in PAF receptor mRNA expression was observed compared to the control group. We demonstrate that PAF receptor immunoreactivity and mRNA are detected mainly in the luminal epithelium, epithelial cells of the superficial glands and to a lesser degree in stroma. Levels of PAF receptor mRNA in bovine endometrial explants were correlated with PAF receptor protein localization assessed by immunohistochemistry. The regulation of PAF receptor by progesterone in bovine endometrial explants suggests that PAF is involved in the physiological process of reproduction.