Part 3 book "Nelson textbook of pediatrics" includes content: The cardiovascular system, diseases of the blood; nephrology, urologic disorders ininfants and children, gynecologic problemsof childhood, the endocrine system, the nervous system, neuromuscular disorders, disorders of the eye, the ear, the skin, bone and joint disorders, rehabilitation medicine, environmental health hazards, laboratory testing in infants and children. | PART The Cardiovascular System XX 2 BMP2 fibroblast growth factor 4 FGF4 the transcription factors Section 1 GATA4 Mesp1 and Mesp2 and members of the Wnt β- Developmental catenin signaling pathway. The clinical importance of these ligands is revealed by the spectrum of cardiac teratogenic effects caused by the retinoid-like drug isotretinoin. Biology of the As early as 20-22 days before cardiac looping the embryonic heart begins to contract and exhibit phases of the cardiac cycle that are Cardiovascular System surprisingly similar to those in the mature heart. Morphologists initially identified segments of the heart tube that were believed to correspond to structures in the mature heart Fig. 420-1 the sinus venosus and atrium right and left atria the primitive ventricle left ventricle the bulbus cordis right ventricle and the truncus arteriosus aorta and Chapter 420 pulmonary artery . However this model is oversimplified. Only the trabecular most heavily muscularized portions of the left ventricular Cardiac Development myocardium are present in the early cardiac tube the cells that will become the inlet portion of the left ventricle migrate into the cardiac tube at a later stage after looping is initiated . Even later to appear are Daniel Bernstein the primordial cells that give rise to the great arteries truncus arterio- sus including cells derived from the neural crest which are not present until after cardiac looping is complete. Chamber-specific transcription factors participate in the differentiation of the right and left ventricles. Knowledge of the cellular and molecular mechanisms of cardiac devel- The basic helix-loop-helix bHLH transcription factor dHAND is opment is necessary for understanding congenital heart defects and expressed in the developing right ventricle disruption of this gene or will be even more important in developing strategies for prevention of other transcriptional factors such as myocyte enhancer factors 2C whether cell or .
