The sinus node is a cluster of cells situated in the upper part of the wall of the right atrium. While skeletal muscle fibers are arranged into regular, non-branching bundles, the muscle fibers of the myocardium branch at irregular angles, and connect to other muscle cells at junctions called intercalated discs. The cardiac muscle consists of much broader, shorter cells that branch. The electrical impulses are generated there. This broadness, and the interdigitations of the cardiac muscle increase its surface area for impulse conduction. (a) Cardiac muscle cells have myofibrils composed of myofilaments arranged in sarcomeres, T tubules to transmit the impulse from the sarcolemma to the interior of the cell, numerous mitochondria for energy, and intercalated discs that are found at the junction of different cardiac muscle cells. There are 3 types of muscle cells in the human body; cardiac, skeletal, and smooth. d. Starling’s law of … Each nucleus regulates the metabolic requirements of the sarcoplasm around it. D) Cardiac muscle cells are found in … Choose all correct answers. Question 1 Which type of muscle has branched cells? Cardiac muscle fibers have a single nucleus, are branched, and joined to one another by intercalated discs that contain gap junctions for depolarization between cells and desmosomes to hold the … A) bone cells B) muscle cells C) adipose cells D) red blood cells 39) Which of the following options best describes the structure of … The sinus node is the heart's natural pacemaker. Purkinje fibers are specialized for conduction. It does this continuously. Cardiac muscles composed of cardiomyocytes cells that are short and slender cells, and rectangular shape cells. 9) A) Striated muscle cells are long and cylindrical with many nuclei. Compared to collagen, many more types of cells can adapt to fibrin scaffolds, including adipose-derived MSC, ESC-derived cardiac cells, iPSCs, smooth muscle cells, and fibroblasts. Although cardiac muscle cannot be consciously controlled, the pacemaker cells respond to signals from the autonomic nervous system (ANS) to speed up or slow down the heart rate. The myocyte is composed of bundles of myofibrils that contain myofilaments (Figure 1). Muscle cells, commonly known as myocytes, are the cells that make up muscle tissue. Part of the boundary membranes of adjacent cardiac muscle cells make very elaborate interdigitations (branchings) with one another under microscopic examination. O Skeletal O Smooth O Cardiac Question 3 What name do we use for the outer membrane of skeletal muscle cells? Another difference is in the cell nuclei: Smooth and cardiac muscle cells possess a single nucleus per cell, and skeletal muscle cells are multinucleated. They are relatively short, branched fibers that measure approximately 10 to 10 micrometers in diameter and 50 to 100 micrometers in length. cardiac muscle contraction Source: MGI cardiac muscle tissue morphogenesis Source: MGI Inferred from mutant phenotype i "Cellular disorganization and extensive apoptosis in the developing heart of mice that lack cardiac muscle alpha-actin: apparent cause of perinatal death." The myofibrils have distinct, repeating microanatomical units, termed sarcomeres, which represent the basic contractile units of the myocyte (Figure 2). The heart muscle responds to stimuli which may be mechanical, electrical or chemical Refractory Period The refractory period of the myocardial fibers is of much longer duration than that of skeletal muscle fibers and lasts approximately as long as the cardiac contraction----- so no continous contraction Skeletal O Smooth O Cardiac Question 2 Which type of muscle cell has striations? Cardiac muscle cells are responsible for providing the power to drive blood through the circulatory system. Cardiac muscle is made from sheets of cardiac muscle cells. Choose all correct answers. Part 2 The Cardiovascular System • Cardiac muscle –Striated –Short –Wide –Branched –Interconnected • Skeletal muscle –Striated Long –Narrow –Cylindrical Properties of cardiac muscle • Cells connected to each other by intercalated discs – Passage of ions between cells – … Contractions of the heart (heartbeats) are controlled by specialized cardiac muscle cells called pacemaker cells that directly control heart rate. In fact, the fibers may branch around a nucleus. For one thing, the initiation of the "beating" of the heart is controlled by special cardiac myocytes, or heart-muscle cells, called pacemaker cells. Contractions of the heart (heartbeats) are controlled by specialized cardiac muscle cells called pacemaker cells that directly control heart rate. Gap junctions, which are part of the sarcolemma, are channels between adjacent fibers of the cardiac muscle. Cardiac Muscle Definition. C) Smooth muscle cells have T tubules. Each cell (fiber) has only one nucleus. Second, cardiac muscle fibers are branched and interconnected. The cardiac muscle cell or fiber. A) cardiac muscle B) smooth muscle C) striated muscle D) skeletal muscle 38) Which type of cell is specialized to store fat in animals? They never get tired. Figure 1. The cells could be induced to differentiate into any one of the three major cardiac lineages by treatment with specific growth factors like PDGF (platelet derived growth factor) for smooth muscle cells, VEGF for endothelial cells and conditioned medium of both fibroblasts and CMs for ventricular-like CMs. The cells of the cardiac muscle tissue are shorter than the skeletal muscle tissue. They typically contain one nucleus, similar cell organelles as skeletal muscle cells, and plenty of acrosomes, which give the desired energy for contraction. Among the major elements in the cardiac conduction system are the sinus node, atrioventricular node, and the autonomic nervous system. This helps the tissue to get locked tightly. In this study, we have compared the exon-skipping activity and the cellular trafficking of Pip6a-PMO in relevant muscular cells, namely, a H2k mdx cell line (as representative of skeletal muscle), in primary cardiomyocytes isolated from newborn mdx mice, as well as in wild-type skeletal and cardiac muscle cells.