Muscle tissue can be categorized into skeletal muscle tissue, smooth muscle tissue, and cardiac muscle tissue. The muscle fibres are made up of long narrow spindle shaped cells that are generally shorter than striated muscle cells. Surrounding the nucleus and throughout most of the cytoplasm are the thick (myosin) and thin (actin) filaments. Cardiac muscle tissue - has branching fibres, one nucleus per cell, striated and involuntary. It forms the contractile component of the digestive, urinary, and reproductive systems as well as the airways and arteries. Tiny projections that originate from the myosin filament are believed to be cross bridges. And proper, spindle-shaped spindles for your favourite stickless whorl. Smooth muscle cells are spindle shaped, have a single, centrally located nucleus, and lack striations. Smooth muscle fibers are located in walls of hollow visceral organs, except the heart, appear spindle-shaped, and are also under involuntary control. A muscle spindle consists of several differentiated muscle fibers (intrafusal fibers) that are enclosed in a spindle-shaped connective tissue sac. Fusiform Muscles Sometimes, included in the parallel muscle group, these muscles are more spindle-shaped, with the muscle belly being wider than the origin and insertion. However, smooth muscle tissue tends to demonstrate greater elasticity and function within a larger length-tension curve than striated muscle. Muscle spindles can be defined as small, spindle-shaped sensory receptors located in skeletal muscle tissue (Fig. Von Economo neurons (VENs), also called spindle neurons, are a specific class of mammalian cortical neurons characterized by a large spindle-shaped soma (or body) gradually tapering into a single apical axon (the ramification that transmits signals) in one direction, with only a single dendrite (the ramification that receives signals) facing opposite. 1. These cells possess a single, central nucleus. Skeletal muscle fibers occur in muscles which are attached to the skeleton. 6.11), and they run parallel to the main muscle fibers (extrafusal fibers). Parasite Rex. Cardiac muscle, found in the walls of the heart, is also under control of the autonomic nervous system. Smooth muscle contracts slowly and rhythmically. And proper, spindle-shaped spindles for … Each cell is spindle shaped with a single nucleus and … They average a length of about 0.2 mm. They are called involuntary muscles. The non-striated (smooth) muscle cell is spindle-shaped and has one central nucleus. The muscle spindle has both sensory and motor components. It crawls along the long muscle fibers and then penetrates one of the long, spindle-shaped cells that make them up. Smooth muscle tissue contraction is responsible for involuntary movements in the internal organs. Skeletal muscle tissue - cylindrical, multi-nucleated, voluntary and striated. Cardiac Muscle. Acquiring a product line. Smooth muscle cannot be controlled consciously and thus acts involuntarily. In the relaxed state, each cell is spindle-shaped, 20–500 micrometers in length. Muscle - Muscle - Structure and organization: Smooth muscle contains spindle-shaped cells 50 to 250 μm in length by 5 to 10 μm in diameter. This ability to stretch and still maintain contractility is important in organs like the intestines and urinary bladder. Skeletal muscle fibers are cylindrical, multinucleated, striated, and under voluntary control. An example is the Deltoid muscle which has three sections, anterior, posterior and middle. 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