title: Morphological study of the sinus node and its artery in yak.
abstract: The sinus node of yak has been studied by the histological methods and transmission electron microscopy. The sinus node artery of yak was also determined by the injection-corrosion casting technique, the angiography, and histological methods. The results showed that the sinus node of yak contained an extensive framework of collagen and two main type cells: pacemaker cells (P cells) and transitional cells (T cells). The P cells had a perinuclear clear zone, contained less myofibrils, and appeared smaller mitochondria than T cells. The T cells were longer and slender than P cells, and had a variety of shapes. At the periphery of sinus node there were many nerve fibers and ganglions. Gap junction did not reveal reaction with anti-connexin43, but it was detected by electron microscopy in the central part of sinus node of yak. The sinus node artery of yak originated from left coronary artery more frequently (98%) than by right (2%). The artery located at the periphery of sinus node. It had an internal elastic membrane throughout its course, and a large nerve bundle was found running in a longitudinal direction.
authors.affiliation: Laboratory of Animal Anatomy & Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China.
authors.forename: Deyong
authors.initials: D
authors.lastname: Duan
authors.forename: Sijiu
authors.initials: S
authors.lastname: Yu
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
mesh_terms: D000818:Animals; D001683:Biological Clocks; D015415:Biomarkers / Q000032:analysis; D002417:Cattle; D003094:Collagen / Q000032:analysis; D018031:Connexin 43 / Q000032:analysis; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D016319:Corrosion Casting; D005724:Ganglia / Q000648:ultrastructure; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D008929:Mitochondria, Heart / Q000648:ultrastructure; D053142:Mitochondrial Size; D009412:Nerve Fibers / Q000648:ultrastructure; D012849:Sinoatrial Node / Q000033:anatomy & histology* / Q000737:chemistry / Q000166:cytology / Q000294:innervation / Q000648:ultrastructure
chemical_list: D015415:Biomarkers; D018031:Connexin 43; D003094:Collagen