because many proteins are secreted as hormones
Skeletal muscle cells,cardiac muscle cells,sperm cells
Yes, skeletal muscle cells have glycosomes and myoglobin in their sarcoplasm.
Cardiac muscle cells are similar because they have striations which are strands of actin and myosin filaments. They also have mitochondria, transverse tubules, and sarcoplasmic reticulum.Cardiac muscle is different from skeletal muscle in that the muscle is branching, with intercalated dicks at the ends of them, store less calcium, the transverse tubules are larger, and their twitches are longer. Also, the entire cardiac muscle contracts as a whole, regulates itself, and is rhythmic.
no, skeletal muscle cells are
skeletal muscle cells have multiple nuclei in each cell.
Skeletal muscle.
Smooth (organs)Cardiac (heart muscle)Skeletal (movement, support, strength)Muscle cells have a nucleus just like other cells. The basic units of a muscle cell are the actin and myosin filaments that slide past each other to allow flexion and extension of your joints.
Actin and myosin are present in all three muscle types. In skeletal and cardiac muscle cells, these proteins are organized in sarcomeres, with thin and thick filaments. The internal organization of a smooth muscle cell is very different: • A smooth muscle fibre has no T tubules, and the sarcoplasmic reticulum (SR) forms a loose network throughout the sarcoplasm. Smooth muscle tissue has no myofibrils or sarcomeres. As a result, this tissue also has no striations and is called nonstriated muscle. • Thick filaments are scattered throughout the sarcoplasm of a smooth muscle cell. The myosin proteins are organized differently than in skeletal or cardiac muscle cells, and smooth muscle cells have more cross-bridges per thick filament. • The thin filaments in a smooth muscle cell are attached to dense bodies, structures distributed throughout the sarcoplasm in a network of intermediate filaments composed of the protein desmin. Some of the dense bodies are firmly attached to the sarcolemma. The dense bodies and intermediate filaments anchor the thin filaments such that, when sliding occurs between thin and thick filaments, the cell shortens. Dense bodies are not arranged in straight lines, so when a contraction occurs, the muscle cell twists like a corkscrew. • Adjacent smooth muscle cells are bound together at dense bodies, transmitting the contractile forces from cell to cell throughout the tissue. • Although smooth muscle cells are surrounded by connective tissue, the collagen fibres never unite to form tendons or aponeuroses as they do in skeletal muscles.
Smooth muscle cells are similar to skeletal muscle cells due to the actin-tropomyosin interactions. These interactions "tell" the muscle when to contract.
The filaments of myofibrils constructed from proteins, myofilaments, consist of 2 types, thick and thin. Thin filaments consist primarily of the protein actin; thick filaments consist primarily of the protein myosin. The protein complex composed of actin and myosin is sometimes referred to as "actomyosin." In striated muscle, such as skeletal and cardiac muscle, the actin and myosin filaments each have a specific and constant length on the order of a few micrometers, far less than the length of the elongated muscle cell (a few millimeters in the case of human skeletal muscle cells). The filaments are organized into repeated subunits along the length of the myofibril. These subunits are called sarcomeres.
Smooth muscle tissue has a single nucleus in each cell :)
Skeletal muscle tissueVoluntary or skeletal muscles contains long non branching cylindrical cells.