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What is the differences between smooth,skeletal and cardiac muscles?
State the cells,length of fibre,fibre arrangement,nucleus,myofibrils,sarcolemmanerve control and location
5 Answers
- Anonymous1 decade agoFavorite Answer
Skeletal muscle is attached to the bones of the skeleton which you use for making voluntary movements. The biceps and triceps are skeletal muscles. Skeletal muscle looks stripey when seen with a light or electron microscope. The stripes are produced by a regular pattern of protein filaments which are lined up to form alternating light and dark bands. Skeletal muscle fibres are very large cells. They can be up to 80 micrometres in diameter and many centimetres long. Each cell has many nuclei which lie close to the cell surface. Inside the cell there are several bundles of myofibrils, containing actin and myosin, which run along the whole length of the cell. Large numbers of mitochondria lie alongside the myofibrils, mostly between them and the cell surface membrane.
Cardiac muscle is found only in the heart. Cardiac muscle differ from skeletal muscle in several ways. The fibre are smaller, each one being about 80 micrometres long and 15 micrometres in diameter. Each cell has one nucleus. These cells branch and form connections with adjacent cells. Cardiac muscle has more mitochondria than skeletal muscle to provide more energy for the long periods of contractions to ensure a continous supply of oxygen.
Smooth muscle is rather different from the previous muscles. It does not look striped under the microscope. It is made up of individual cells each with their own nucleus. The cells are quite long and thin, about 400 micrometres long and 5 micrometres wide. They lie parallel to each other. Smooth muscle is found in many places in the body, including the walls of the alimentary canal, blood vessels and the uterus. It is not under voluntary control.
- 1 decade ago
Smooth muscle - spindle shaped muscle without striations histologically, hence the term "smooth". They are involuntary muscles which are usually found in the walls of blood vessels, respiratory, digestive and urinary tracts. They're innervated by the autonomic nervous system.
Skeletal / straited muscles - are names as such because they're in close association with the skeletal system. They appear to have light and dark bands histologically hence the term striated or striped. If I remember correctly the light and dark bands correspond to the areas aligned M and Z bands. Control comes from the precentral gyrus and the descending tracts but the cerebellum also makes contributions.
Cardiac muscle is involuntary and it appears straited too. the straitions result also from the alignment of the bands. Innervation is from the autonomic nervous system too. What differentiates cardiac muscle from skeletal muscle is its branch-like appearance histologically and the free flow of ions between individual cells which facilitates the contraction of the heart as a single coordinated unit. A subset of cardiac muscle is called the purkinje system which makes up the conduction system of the heart.
- 1 decade ago
The above answers are well said. I just want to add that cardiac muscles contain intercalated discs. Which is a major difference between cardiac and skeletal, because both are sometimes referred to as striated muscles. Cardiac is the only muscles that contain intercalated discs.
- Anonymous1 decade ago
Well cardiac muscules would be heart muscules so they are probably shorter than most skelatal muscules like your biceps and quads.
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- Anonymous5 years ago
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