What does the human body's muscle tissue consist of?

The basic tissue of animals composed of specially differentiated muscle cells. There is a small amount of connective tissue between muscle cells, as well as capillaries and nerve fibers. Muscle cells are elongated in shape and are therefore called muscle fibers. The cell membrane of a muscle cell is called the sarcolemma and its cytoplasm is called sarcoplasm. These are considered to be relatively professional explanations. Let us now take a brief look at the composition of human muscle tissue.

1. Meat tissue is the basic tissue of animals composed of specially differentiated muscle cells. There is a small amount of connective tissue between muscle cells, as well as capillaries and nerve fibers. Muscle cells are elongated in shape and are therefore called muscle fibers. The cell membrane of a muscle cell is called the sarcolemma and its cytoplasm is called sarcoplasm. Sarcoplasm contains myofilaments, which are the material basis for muscle cell contraction. According to the morphology and distribution of muscle cells, muscle tissue can be divided into three categories: skeletal muscle, cardiac muscle and smooth muscle. Skeletal muscles are generally attached to bones by tendons, but there are exceptions, such as the muscle layer of the upper esophagus and the muscles of facial expression, which are not attached to bones. The myocardium is distributed throughout the heart, forming the myocardial layer on the walls of the atria and ventricles, and is also found on the walls of large blood vessels close to the heart. Smooth muscles are distributed in internal organs and blood vessel walls. The muscle fibers of skeletal muscle and cardiac muscle have striations, also known as striated muscle. Smooth muscle fibers have no striations. Muscle tissue has contractile properties and is the source of power for movements of the trunk and limbs, as well as physiological processes such as digestion, respiration, circulation and excretion in the body. The contraction of skeletal muscles is controlled by the will and is considered voluntary muscle. Myocardial and smooth muscles are involuntary muscles that are controlled by autonomic nerves.

2. Skeletal muscle fibers are generally long cylindrical, about 1 to 40 mm long and 10 to 100 microns in diameter. Each muscle fiber is surrounded by a thin layer of connective tissue called the endomysium. Several to dozens of muscle fibers are gathered into muscle bundles. Outside the muscle bundles is a thicker connective tissue called perimysium. A muscle is composed of many muscle bundles, and the connective tissue on its surface is called epimysium, also known as deep fascia. There are abundant blood vessels in each connective tissue, and a capillary network surrounds the muscle fibers in the endomysium. There are afferent and efferent nerve fibers in the connective tissue of the muscle, all of which are myelinated nerve fibers. The nerves distributed on the blood vessel walls within the muscles are autonomic nerves and are unmyelinated nerve fibers.

3. Smooth muscle fibers are generally spindle-shaped, about 20 to 300 microns long and about 6 microns in diameter. The smooth muscle of the uterus during pregnancy can reach 500 microns in length. The nucleus is oblong and located in the central basement membrane of the muscle fiber, attached to the outside of the sarcolemma. Smooth muscles are often arranged in bundles or layers. According to the distribution of their nerve endings, they can be divided into two categories: one is a minority, with nerve endings distributed on the surface of muscle cells, and their endings are bead-like and swollen, while most other smooth muscle cells do not have nerve endings. These cells transmit information through the suture connections of smooth muscle cells to spread nerve impulses. Most smooth muscles in the body, such as those distributed in the digestive tract and uterine wall, belong to this category. The other type is the majority, in which each muscle cell has nerve endings distributed on the surface, and each cell is directly controlled by the nerves. For example, the sphincter and dilator pupillae of the eye belong to this category. In addition, there are intermediate types. In addition to its contractile function, smooth muscle also has the function of producing extracellular matrix.

The above explains the issue of human muscle tissue. Nowadays, many people do not know the structure or composition of their bodies. These are considered to be relatively professional academic issues. For the sake of a good body and our own health, we usually need to pay more attention to our own bodies, and go to the hospital in time if we find any problems.