Morphofunctional aspects of the myocardicsheath in the cranial vena cava of the bovine (Bos indicus)

Data about the functional valve structure of the cranial vena cava in the right atrium of bovines are scarce. We have done a histological study in ten bovines to observe the functional architecture of the conective-muscular wall of the cranial vena cava. After fixation, the intrapericardiac segment was harvested and embedded in paraplast. Transverse and longitudinal sections, which were stained by Masson's Trichromic, Mallory Hematoxylin, Cloridic Orcein and Calleja methods were obtained. We have observed cardiac muscular fibers comming from the atrial musculature. We believe that, during the atrial systole, the contraction of the cardiac muscular fibers, like a spiral, reduces the venous length and increase its diameter, resulting in the blood push into the atrial chamber.

Description of nodal fibers in the cranial vein cava walls of the bovine (bos indicus)

Muchas investigaciones han estudiado la presencia de fibras musculares estriadas cardíacas, con características de fibras nodales en las paredes de la vena cava y del seno coronario de mamíferos. Sin embargo no hay un consenso sobre la localización exacta de estas fibras. El objetivo de este trabajo fue identificar estas fibras en la vena cava craneal de bovino. Para este propósito, utilizando 10 corazones bovinos con los vasos de la base, fijados en formol 10 por ciento. Después de la fijación, el segmento intrapericárdico fue aislado e incluido en paraplástico. Se obtuvieron cortes transversales y longitudinales los que fueron sometidos a coloración con tricrómicos de Masson y Mallory, orceína clorhídrica de Unna-Taenzer y Calleja. Los resultados microscópicos revelaron que estas fibras nodales están localizadas en las paredes ventral e izquierda de la vena cava craneal a nivel de la desembocadura en el atrio derecho. Concluimos que estas fibras presentes en las paredes de la vena craneal, transmiten el estímulo eléctrico originado en el nodo sinoatrial para toda musculatura atrial, hasta las paredes venosas, causando la constricción del ostio venoso impidiendo el reflujo venoso durante la sístole atrial

Microscopic observations on the great saphenous vein at the upper third level of the thigh and at the level of discharge into the femoral vein

For the microscopical study of the great saphenous vein wall, the venous segments from six male necropsiedcadavers: were obtained three young individuals between 16 and 35 years old and three aged individuals between 50 and 83 years old. The tunica media of the great saphenous vein at the upper third level of the thigh belonging to both young and aged individuals is made up of two layers: an internal formed by fascicles of smooth longitudinal muscular fibers and the external layer made up by fascicles of smooth circular muscular fibers. At the level of the discharge in the femoral, the tunica media of the great saphenous vein wall of both, young and aged individuals, is made up of one layer, whose fascicles of smooth muscular fibers are circularly orientated in relation to the vascular axis. The tunica adventitia of the great saphenous vein wall at the upper third level of the young individuals thigh, presents elastic fibers whereas it the aged individuals it is made up of fascicles of smooth longitudinal fibers; at the level of the femoral vein disdarge in both young and aged individuals, the tunica adventitia presents a fiber elastic constitution. The young and aged individuals' parietal venous valve is elastic fiber in nature. The young individuals' ostial valve is also elastic and that of aged individuals is muscular fiber in nature.

Structure of the vena cava caudalis of the dog (canis familiaris)

El objetivo de este trabajo fue proporcionar datos exactos que permitan identificar la estructura y comportamiento de los elementos "tisulares" presentes en las porciones de origen "pre renal" y post renal" de la pared de la vena cava caudal del perro. Las observaciones nos permitieron concluir que la vena cava caudal es un vaso fibromuscular que tiene la capacidad para propulsar la sangre venosa de vuelta al atrio derecho

Anatomical observations on the human great saphenous vein

During the dissections of the lower limbs we observed that the most frequent occurrence of the forms of discharges of the great saphenous vein tributaries was one observed in 29.09 per cent of the cases, where the superficial epigastric vein and superficial circumflex iliac vein make up a veinous trunk discharging in to the great saphenous vein, and the external pudendal and the "lateral accessory saphenous" veins drain separately into the great saphenous vein. In the male right lower limbs, the average distance between the pubic tubercle and the great saphenous vein arch upper border was 3.98cm and 3.9lcm for the left lower limbs. In the male right lower limbs, the diameter average of the great saphenous vein arch was l.O2cm and l.O6cm for the male left lower limbs. At the hiatus saphenus level, the wall of lhe great saphenous vein clings to the sieved fascia and the femoral sheath. We have observed the presence of the parietal venous valve at the lumen of the great saphenous vein upper segment; and also the ostial venous valve near the draining of the great saphenous vein into the femoral vein.

Estrutura microscópica da parede da veia porta no cao (Canis familiaris, L.) / Microscopic struture of the portal vein wall in the dog (Canis familiaris, L.)

No cao, o estudo microscópico revela que a parede da veia porta apresenta três túnicas: (1) uma túnica íntima onde o endotélio repousa sobre fina rede de fibras elásticas, subendotelial; (2) uma túnica média e (3) uma túnica externa. Estas últimas túnicas sao formadas por numerosas células musculares lisas entremeadas por fibra elásticas e colágenas