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. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.

Segmentation features and structural organization of the intrapulmonary artery of the yak

“…As a special plateau animal, many scholars have studied the yak in plateaus, focusing on reproductive organ anatomical features and ovarian morphology (Cui et al, 1999a,b;Yong et al, 2005), the pineal gland and thyroid structure (Wang et al, 2007), cranial neck ganglia and its branch (Shao et al, 2007(Shao et al, , 2008, ventricular microvascular morphology He et al, 2010), pulmonary microvasculature (Du et al, 2009), the sinus node and its artery (Duan et al, 2012), and placentome morphometric analysis (Liu et al, 2010). Studies on the plateau adaptive mechanism of the yak are available in the literature, including histochemical and ultrastructural observations of the respiratory epithelium and gland in Bos grunniens , morphological studies on the lung of yak , local anatomy of yak lung (Heath et al, 1984), structural characteristics and plateau adaptability of yak lung (Chen et al, 2006), and distribution of vascular endothelial growth factor in plateau yak lung .…”