Muscles in the body are known by several names, including tendons, myofibrils, sarcolemma, and terminus arteriole. Some of these are named after the bones they attach to (for example, the sternomastoid connects the sternum and clavicle to the mastoid process of the skull), while others are named according to their connection to a moving bone, such as the occipitofrontalis, which connects the occipital bone to the frontal bone.
The tendons of muscles in the body are made up of a matrix composed of collagen fibers and proteoglycan. The latter contributes to the strength and tensile characteristics of the tendon. The tendons are usually round, but some are flat. The shape of the tendons depends on their role within the body. Some of the tendons are used to connect muscles and other body parts. This article will provide an overview of the structure and function of tendons.
Myofibrils are filamentous structures within skeletal muscles. They are composed of sarcomeres and have a thickness of less than one micron. Myofibrils are white in color and contain more myofibrils than sarcoplasm, which makes them shrink more rapidly. On the other hand, red fibers contain more myoglobin and have fewer myofibrils.
Sarcolemma muscles in the body have specialized cytoplasm called sarcoplasm. They contain abundant myofibrils and a modified endoplasmic reticulum (SER). These structures conduct impulses from the cell surface to the SARCOPLASMIC RETICULUM. Sarcolemma muscles in the body are found in all body parts. These muscle fibers are located in the legs, arms, and thigh muscles.
As blood flows through an artery, changes in its diameter affect the way that it flows. An arteriole contracts or dilates in response to the metabolic need of different tissue types. This process occurs via neuronal or chemical signals. When an arteriole contracts, blood flows past that tissue, and when it dilates, blood flows to another location. Although there are a variety of mechanisms that regulate the blood flow through an artery, vasoconstriction is the primary mechanism for the distribution of blood.