1. Schematic diagram showing arrangement of thick and thin filaments within the sarcomere. Thick filaments contain myosin, myosin-binding protein C, and titin. The tails of the myosin heavy chains are woven together to form the thick filament. The globular head projects outward to form cross bridges. The thin filaments include actin (which forms the backbone of the thin filament), the troponins, and tropomyosin. Tropomyosin binds to troponin T at multiple sites along the major groove of the actin filament and inhibits actin-myosin interaction. Troponin T binds the troponin complex to tropomyosin, troponin I inhibits interactions between actin and myosin, and troponin C binds calcium. The sarcomere, which lies between two Z-discs, is anchored by interactions between titin and actin with Z-disc proteins, including LIM domain-binding protein 3 (cipher/ZASP), α-actinin, cardiac LIM domain protein (MLP), and telethonin. Adapted from Mahony L. Development of myocardial structure and function. In: Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, eds. Moss and Adams’ Heart Disease in Infants, Children and Adolescents, 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:577.
Source: Myocyte Contraction and Relaxation, Neonatal Cardiology, 3e
Citation: Artman M, Mahony L, Teitel DF. Neonatal Cardiology, 3e; 2017 Available at: Accessed: December 26, 2017
Copyright © 2017 McGraw-Hill Education. All rights reserved