Nav1.5 kb. The gene consists of 28 exons, of which exon 1 and in part exon 2 form the 5’ untranslated region (5’UTR) and exon 28 the 3’ untranslated region (3’UTR) of the RNA. SCN5A is part of a family of 10 genes that encode different types of sodium channels, i.e. brain-type (Na1.1, Na1.2, Na1.3, Na1.6), neuronal channels (Na1.7, Na1.8 and Na1.9), skeletal muscle channels (Na1.4) and the cardiac sodium channel Na1.5. SCN5A is mainly expressed in the heart, where expression is abundant in working myocardium and conduction tissue. In contrast, expression is low in the sinoatrial node and atrioventricular node.
Lymph node stromal cell the "T cell zone". B lymphocytes (cells which help to fight certain bacteria) are located in the "B cell follicle". The primary B cell follicle matures in germinal centers. In the medulla are hematopoietic cells (which contribute to the formation of the blood) and stromal cells. Near the medulla is the hilum of lymph node. This is the place where blood vessels enter and leave the lymph node and lymphatic vessels leave the lymph node. Lymph vessels entering the node do so along the perimeter (outer surface). The lymph nodes, the spleen and Peyer's patches, are known as secondary lymphoid