Morphology of Lymphatics of the Mammalian Heart with Special Reference to the Architecture and Distribution of the Subepicardial Lymphatic System

Abstract

The subepicardial lymphatic system in the rat and dog heart has been investigated by means of scanning electron microscopy. Following application of hydrogen peroxide, the epicardium was removed with a forceps under a dissecting microscope. The subepicardial region contained a well-developed lymphatic system which consisted of the main lymphatic trunks and lymphatic capillaries. The lymphatic trunks of large diameters ran from the apex of the heart to its base. The subepicardial lymphatic capillaries were ramified and anastomosed with each other to form a relatively dense network which extended over the entire surface of both ventricles. These networks joined the main lymphatic trunks. Further, some similar networks were connected with the underlying myocardial lymphatic capillaries.

The Lymphatic Vasculature in the 21st Century: Novel Functional Roles in Homeostasis and Disease

“…As development progresses, lymphatic vessels expand over the dorsal and ventral surfaces and into the myocardium during late embryonic and postnatal stages. In humans, cardiac lymphatics span all layers of the heart (Bradham and Parker, 1973;Shimada et al, 1989), but most cardiac lymphatics in mice are found in the subepicardium and outer myocardium (Flaht-Zabost et al, 2014). Cardiac lymphatic vessels play important roles in maintaining tissue fluid balance and immune surveillance and are implicated in myocardial infarction (MI).…”

Formation and Growth of Cardiac Lymphatics during Embryonic Development, Heart Regeneration, and Disease

“…In mammals, including humans, all the layers of the heart harbor lymphatic vessels (Fig. 1;Shore 1929;Bradham and Parker 1973;Shimada et al 1989). The subepicardial lymphatics, first described by Rudbeck in the 17th century (Rudbeck 1653), are complemented by a wide capillary network in the myocardium and one located between the endocardium and the layer of Purkinje nerve fibers (Johnson and Blake 1966).…”

Anatomy and roles of lymphatics in inflammatory diseases

“…43,44 Microscopically, these lymphatics share anatomical and physiological characteristics of other tissues. Subendocardial plexuses are networks of lymphatic capillaries found in the connective tissue between the endocardium and myocardium that form branches running parallel to the endocardial surface.…”