Tunica adventitia or tunica externa is the outer layer of the blood vessel wall. It consists of connective tissue with vasa and nervi vasorum and plays a key role in vascular health. The aim of our study was to compare the wall layers beyond tunica media in arteries of different type and location. The following arteries of pig, dog and cat were processed histologically and analysed by light microscopy: aorta ascendens, arcus aortae, aorta thoracica, aorta abdominalis, arteria (a.) femoralis, a. tibialis cranialis, a. carotis communis, a. lingualis, a. basilaris, a. cerebralis media, a. testicularis and aa. jejunales. We found two layers of connective tissue outside the media: (1) a compact layer with many elastic fibres in muscular and few in elastic arteries and (2) an outer layer of loose connective tissue. The compact layer was missing in aorta ascendens, arcus aortae and intracranial vessels. Adventitial stripping removed only the loose connective tissue layer. In spite of the still present compact layer, stripped arteries were very flimsy. We suggest using the term 'tunica externa' for the compact connective tissue layer and 'tunica adventitia' for the outermost loose connective tissue layer as in other organs. The presence of the tunica externa differs between species, arteries and arterial side, as well as the removability of tunica adventitia and tunica externa by anatomical dissection.
- MeSH
- adventicie anatomie a histologie MeSH
- aorta abdominalis anatomie a histologie MeSH
- aorta thoracica anatomie a histologie MeSH
- elastická tkáň anatomie a histologie MeSH
- kočky anatomie a histologie MeSH
- prasata anatomie a histologie MeSH
- psi anatomie a histologie MeSH
- svaly hladké cévní anatomie a histologie MeSH
- zvířata MeSH
- Check Tag
- kočky anatomie a histologie MeSH
- psi anatomie a histologie MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Wall remodeling in varicose veins is associated with hypertrophy of subendothelial tissue, increase in inner diameter, wrinkling and invagination of the endothelial layer. Due to structural alterations of the wall, the smooth muscle cells (SMCs) change their original circular and longitudinal orientations. Our aim was to quantify the volume fraction of circularly, longitudinally and obliquely oriented SMCs within both the inner and outer half of the wall of 11 great saphenous varicose veins and five small saphenous varicose veins. Using stereological methods applied on cross-sections of the vessels regularly gained each 5 cm along the vessel we determined the wall thickness (846 ± 319 μm, mean ± standard deviation), the volume fraction of circular SMCs in the inner (0.19 ± 0.13) and outer (0.06 ± 0.06) layers, the volume fraction of longitudinal SMCs in the inner (0.06 ± 0.05) and outer (0.05 ± 0.04) layers, the volume fraction of oblique SMCs in the inner (0.15 ± 0.08) and outer (0.09 ± 0.08) layers, and the total volume fraction of SMCs in the inner (0.4 ± 0.1) and outer (0.21 ± 0.09) layers. The volume fraction of SMCs with circular and oblique but not with longitudinal orientation was greater in the inner layer compared to the outer layer. The SMC orientation distribution was uniform along the varicose saphenous veins. With increasing wall thickness, the volume fraction of longitudinal and oblique SMC bundles increased in both layers at the expansion of circular SMC bundles. The main differences in the orientation of the SMCs in the inner and outer wall layers should be taken into account when computational modeling of varicose saphenous veins is attempted.
- MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- myocyty hladké svaloviny fyziologie ultrastruktura MeSH
- senioři MeSH
- svaly hladké cévní anatomie a histologie patologie fyziologie MeSH
- tunica media patologie MeSH
- varixy patologie MeSH
- vena saphena patologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
