Skeletal Muscle Essay

Contractility of ASM requires an increased levels of intracellular Ca2+. When surface receptors are not activated, Ca2+ levels are low. Upon activation of these cell surface receptors by contractile agonists e.g. acetylcholine, serotonin and histamine, intracellular Ca2+ increases causing a contraction (9). Smooth muscle cell contraction is controlled by both receptor and mechanical activation of proteins actin and myosin and also changes to membrane potential.

Skeletal Muscle Structure.The cells of skeletal muscles are long fiber-like structures. They contain many nuclei and are subdivided into smaller structures called myofibrils. Myofibrils are composed of 2 kinds of myofilaments. The thin filaments are made of 2 strands of the protein actin and one strand of a regulatory protein coiled together. The thick filaments are staggered arrays of myosin molecules.

types of muscle tissues : skeletal, cardiac, smooth. Each of these different tissues has the ability

These muscle tissue cells specialised to contract and move parts of the body. It is also capable of responding to stimuli. There are three types of muscle in the body such as: skeletal, cardiac and smooth. Each muscle is created of muscle fibers that are capable of contracting and returning back to original state-relaxation. Contraction causes movement of the skeleton, soft tissue, blood or specific material. Skeletal muscle is attached to the bones of the skeleton. Some facial muscles are attached to the skin. They have direct control over them through nervous impulses from our brain sending messages to the muscle. Contractions can vary to produce fast, powerful movements. These muscles also have the ability to stretch and contract to return to original shape. Cardiac muscles are found in the chambers of the heart such as the atria and ventricles. It is under the control of the automatic nervous system; however, even without nervous input contractions can occur. It is completely different to all the other muscles. Smooth muscles are also known as involuntary due to our inability to control its movement. This muscle is usually found in the walls of hollow organs

Rationale, Significance and Hypothesis. An extrinsic factor, which exerts a dominant influence on skeletal muscle fiber phenotype, is the nervous system. Buller et al. (1960) elegantly demonstrated the plastic nature of skeletal muscle fibers in response to changes in innervation type. Later, Lφmo and Westgaard (Lφmo and Westgaard, 1974; Westgaard and Lφmo, 1988) demonstrated that depolarization of muscle with specific patterns and frequencies of electrical activity are sufficient to cause changes in mature muscle fiber phenotypes. However, how myofibrillar gene expression and structural organization is affected by the frequency of impulses during activity, the amount of activity over time, or other characteristics of patterned activity is essentially unknown. To answer these questions will require the isolation and study of subsets of muscle-specific proteins in relation to different electrical activation patterns in vivo, an issue that cannot be easily addressed in preparations currently used in the study of muscle development and maintenance. However, using novel in vivo approaches can, in part, circumvent this difficulty.

Skeletal muscles allow the bones to move; smooth muscles aid in digestion; cardiac muscles pump blood throughout the body.

Skeletal tissue is voluntary which means that it is used in the movements of the skeletal components.

There are three types of muscle tissue: skeletal, cardiac and smooth muscle. Skeletal muscle is attached to bones and helps with movement. Cardiac muscle is found the heart helping the heart to contract and pump blood through an organism. Smooth muscle lines the walls of organs in the digestive and urogenital tracts.

There are three types of muscle tissues in the human body: skeletal, smooth and cardiac muscle. Skeletal muscles are striated muscles that attach to the bone by tendons and permit movement. Skeletal muscles promote movement by contracting and relaxing in response to voluntary messages from the nervous system, deeming skeletal muscles, the only voluntary muscles in the human body. Smooth muscles are involuntary muscles found inside the walls of the stomach,

Muscle is formed with a long and thin tissue called muscle tissue which moves the organs and organisms, and the muscle tissue is made out of a group of cells called the muscle fibers. There are three types of muscle: skeletal muscle, smooth muscle, and cardiac muscle. Skeletal muscle is the muscle who moves the bones, it has much longer fibers than the smooth muscles. Smooth muscle forms the walls of organs, for example, the wall of a stomach. Cardiac muscle is the muscle that forms the heart. From the cross-section view of a muscle, it shows that there is a layer of muscle sheath around the outermost layer of the muscle. The blood vessels that brings glucose and oxygen to the muscle are weaved in the fibers, and there is a layer of epithelial cells around the muscle to keep the fibers together.Muscle tissue can repair itself, but with round scar tissue instead of long, stretchy fibers. Skeletal

In Anatomy and Physiology, one of the topics this class recently covered was the muscle system. In the video, “How Your Muscular System Works” published in 2017 by Emma Bryce said a brief explanation of how the muscular system works. In the video, Bryce stated, “Each time you take a step, two hundred muscles work in unison to lift your foot, propel it forward, and set it down.” Indeed, each muscle is responsible to do a specific movement. The muscle system is a very important system because this is where the three types of muscles come from. For example, in the video, it talked about the skeletal muscle, cardiac muscle, and the smooth muscle. The skeletal muscle is involuntary muscle and voluntary muscles. In addition, the cardiac muscle and the smooth muscle are only involuntary muscles. The cardiac muscle is only found in the heart. The smooth

Smooth muscles are found in the skin, internal organs, reproductive system, major blood vessels, and excretory system. Skeletal muscles are composed of long fibers surrounded by a membranous sheath, the sarcolemma. Since the Skeletal muscles are under control by whom ever they belong to are called voluntary muscles. This muscle is attached to two or more bones which are then attached to the skeleton by tendons. For example, head and neck muscles; contraction of these muscles produces facial expressions and head movements. They are also responsible for speech and swallowing. Skeletal muscles are the main muscles which move your body. Muscles nearly always work in coordinated groups; contraction of one muscle is accompanied by relaxation of another, while other muscles stabilize nearby joints. Then the last of the muscle types is the Cardiac Muscle or the involuntary muscles. Cardiac muscles are not under conscious control they do not react by a persons decision or movement. and are connected to the nervous system which are stimulated by autonomic impulses. Cardiac muscles are found in your internal organs like the heart or the intestine. For example; they include muscles that propel food through the intestine and those that control sweating and blood pressure.

Multiunit smooth muscle highlights strands that are to some degree disorganized and occur as particular filaments as opposed to sheets. It can be found in the iris of the eyes and in the walls of veins. Multiunit smooth muscle tissue contracts when stimulation by motor nerve impulses. Visceral smooth muscle is made out of sheets of spindle-shaped cells in close contact with each other. This more common variety is found in the walls of hollow, visceral organs, for example, the stomach, digestion tracts, urinary bladder, and uterus. The filaments of visceral smooth muscles are equipped for stimulating one another. In this way, when one fiber is stimulated, the impulse might energize nearby strands that, thusly, might energize others. Visceral

1. Why does the force begin to decrease with time? Note that a decrease in force indicates muscle fatigue.

Both of these muscles expand and contract as they have complex structures so it is essential how they do this. The cardiac muscle needs the contractions to occur in order to pump blood out of the atria and into the ventricles and round the circulatory system so the structure of this muscle shows the systole of the heart. The contractions of the skeletal muscle also depend on its structure. The binding and releasing of two strands of sarcomere is how the repeated pattern of contractions occurs. ATP is used to prepare myosin for binding to allow the contractions to happen. The skeletal and cardiac muscle also both has elasticity. The elasticity is used to restore the muscles back to their original lengths which enable them to resume back to their original length once they have contracted and been stretched.