Blood Vasculature of the Lymph Node in the Dog: Anatomical Evidence for Participation of Extrahilar Arterial Vessels in the Blood Supply of the Cortex

Abstract

The organization of the arterial vessels of dog lymph nodes (LN) was studied using methods of visualization of the vasculature by systemic injection of different tracers (colloidal carbon, Micropaque® resin and methylmethacrylate) followed by observation of the samples by light microscopy (after clearing of the thick sections of LN) or scanning electron microscopy (corrosion casts). LN from all of the three groups of nodes studied (tracheobronchial, paratracheal and popliteal) showed an extensive network of arterial vessels encircling the capsule of the organ. We found that branches of these capsular arteries penetrated deeply into the cortical domain of LN. The capsule-originating vessels appeared to have a significant participation in the blood supply of the LN parenchyma at the cortical domains of the organs. Our findings are in contrast with current views on the angiology of the LN that consider that virtually all of the arterial capillaries of the LN parenchyma come from hilar arteries. We propose, therefore, that important segments of the LN cortex receive their blood supply from capsular arteries rather than from hilar vessels.

Three-dimensional analyses of vascular network morphology in a murine lymph node by X-ray phase-contrast tomography with a 2D Talbot array

“…He investigated the microcirculation in murine LNs and presented an arterial blood supply which spreads over the entire upper surface of the investigated inguinal LN. Despite this, similar results for dog and sheep LN support these findings (11,12) yet, the general idea of the hilus as a definite point remained untouched over the years. With the 3D data provided within this study we suggest defining the hilus not as a definite point but rather a large area where blood-and lymphatic vessels enter and emerge, respectively.…”

“…The hilus is commonly described as a narrow entry for the efferent lymphatic vessel which penetrates the capsule at the point of indentation together with one artery and one vein. Only few studies suggest that the blood supply is not restricted to one entering arteriole, but either conclusive three-dimensional (3D) data or the relation of blood vessels to the surrounding structures like the LN capsule are missing or experiments refer to species like dog and sheep (10)(11)(12). Textbook knowledge describes that one artery enters the LN via the hilus and immediately branches into smaller arterioles.…”

Vascularização arterial e venosa do linfonodo poplíteo em cães

“…Da mesma forma, as veias emergentes de tal estrutura dirigem-se a um único vaso sangüíneo venoso, a veia safena lateral. Ainda conforme resultados obtidos, tais ramos, sejam estes arteriais ou venosos, não apresentam um local único de inserção ou emergência, ocorrendo estes aleatoriamente ao órgão, indo, portanto, de encontro às observações de Salvador, Pereira e Grande 9 e Salvador et al 10 em relação ao linfonodo traqueobraquial em cães e dos dois últimos autores. Outro fato constatado e relevante nos resultados foi a presença de sulcos em vários dos linfonodos, bem como a existência de dois linfonodos em um mesmo membro pélvico, totalmente individualizados e com vascularização, arterial e venosa, próprias.…”

Association between anthropometric markers and asthma control, quality of life and pulmonary function in adults with asthma

“…The best of three acceptable manoeuvres of the forced expiratory curve was selected. FVC, FEV 1 and FEV 1 /FVC were registered and expressed as a percentage of the predicted values and as absolute values (21) .…”