Search results
Results from the WOW.Com Content Network
[1] The endocardium underlies the much more voluminous myocardium, the muscular tissue responsible for the contraction of the heart. The outer layer of the heart is termed epicardium and the heart is surrounded by a small amount of fluid enclosed by a fibrous sac called the pericardium. [2]
The endocardial cushions are thought to arise from a subset of endothelial cells that undergo epithelial-mesenchymal transition, a process whereby these cells break cell-to-cell contacts and migrate into the cardiac jelly (towards the interior of the heart tube). These migrated cells form the "swellings" called the endocardial cushions seen in ...
This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos . The tubular heart quickly differentiates into the truncus arteriosus , bulbus cordis , primitive ventricle , primitive atrium , and the sinus venosus .
The endocardial tubes have an intimate proximity to the foregut or pharyngeal endoderm. [1] As folding of the embryo in the horizontal plane initiates in the 4th week of gestation, the endocardial tubes meet in the midline to form the primitive heart tube, which will eventually develop into the histologically definitive endocardium.
The Purkinje fibers, named for Jan Evangelista Purkyně, (English: / p ɜːr ˈ k ɪ n dʒ i / pur-KIN-jee; [1] Czech: [ˈpurkɪɲɛ] ⓘ; Purkinje tissue or subendocardial branches) are located in the inner ventricular walls of the heart, [2] just beneath the endocardium in a space called the subendocardium.
Multiple choice items consist of a stem and several alternative answers. The stem is the opening—a problem to be solved, a question asked, or an incomplete statement to be completed. The options are the possible answers that the examinee can choose from, with the correct answer called the key and the incorrect answers called distractors. [4]
Quizlet is a multi-national American company that provides tools for studying and learning. [1] Quizlet was founded in October 2005 by Andrew Sutherland, who at the time was a 15-year old student, [ 2 ] and released to the public in January 2007. [ 3 ]
A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. [1] Examples of biological systems at the macro scale are populations of organisms.