How do neurons and neuroglia cells work together? The three types of cell junction recognised as making up an intercalated disc are desmosomes, fascia adherens junctions, and gap junctions. Some myelin sheaths are relatively thin, while others can be very thick, many times thicker than the diameter of the axon it is myelinating. Smooth muscle is an involuntary muscle that is less structured and more easily altered compared to striated muscles. amed for their star shape, they have many processes extending from their main cell body. A second feature of cardiomyocytes is the sarcomeres, which are also present in skeletal muscles. In fact, cell organelles are also concentrated in this cytoplasmic region around the nucleus. Cardiac muscle-the muscle fibre consist of short cells with centarlly placed nuclei and numerous striated myofibrils. Each gap is called a. and assists with the speed of conduction along an axon. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. The fibers are relatively wide and very long, butunbranched. Small motor units permit very fine motor control of the muscle. In addition, calcium channels are also present in the walls of the T tubule system, rather than being limited strictly to the sarcoplasmic reticulum. View the University of Michigan WebScope to explore the tissue sample in greater detail. [5] Additional signs indicating forceful myocardial contraction are: [4] [5] Read more. Cardiac muscle cells branch freely. Describe the divisions of the nervous system and their contents. Cardiac muscle fibers cells also are extensively branched and are connected to one another at their ends by intercalated discs. Morphologically skeletal myocytes are elongated and tubular and appear striated with multiple peripheral nuclei. Attached cells form long, branching cardiac muscle fibers that act as a syncytium, allowing the cells to synchronize their actions. Neuroglia provide support and nutrients for neurons. Not all axons are myelinated, and unmyelinated axons have the slowest conduction speed. Cardiac hypertrophy means an increase in size of cardiomyocytes. Notice mitochondria and glycogen particles lying between myofibrils. Visible striations in skeletal and cardiac muscle are visible, differentiating them from the more randomised appearance of smooth muscle. What is the purpose of intercalated discs quizlet? Essentially, the contractile stimuli is propagated from one cell to the next one, resulting in a synchronous contraction of the entire tissue section. Creative Commons Attribution 4.0 International License, Describe intercalated discs and gap junctions.

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