Muscle And Smooth Muscle

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

Q2 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.

Crystal Nguyen School of Anatomy, Physiology and Human Biology, The University of Western Australia, WA, 6009 Introduction Smooth muscle contraction occurs when calcium is present in the smooth muscle cell and binds onto calmodulin to activate myosin light chain kinase (Wilson et al., 2002). Phosphorylation of myosin light chains result in myosin ATPase activity thus cross-bridge cycling occurs causing the muscle to contract (Horowitz et al., 1996). There are two known models of excitation and contraction in smooth muscle, electromechanical coupling (EMC) and pharmomechanical coupling

P3-Types of muscle There are three main types of muscle tissue in the body: Skeletal muscle, smooth muscle and cardiac muscle. Firstly, skeletal muscle has a stripped appearance when it is examined under a microscope so it is sometimes known as striated/stripped muscle. Skeletal muscle is voluntary and this means that it is under conscious control. Secondly, there is smooth muscle which is an involuntary muscle that operates without any conscious control. This muscle is controlled by the nervous system. Smooth muscle can be found in the blood vessels and the walls of the digestive system and it helps to control digestion and blood pressure. Lastly, there is cardiac muscle which is located in in the wall of the heart. Cardiac muscle is involuntary and this means that it is not under conscious control. This is made up of a specialised type of tissue which is striated and it has its own blood supply. The contractions aid the pumping of blood through the blood vessels

Muscle tissue 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

Muscles Diagram 1 Muscle fibres, as shown in Diagram 1, consist of myofibrils, which contain the proteins, actin and myosin, in specific arrangements . The diagram illustrates how a muscle is made up of many fascicles, which in turn are made up of many endomysiums, and within them, many muscle fibres. Each muscle fibre is made up of many myofibrils that consist of sarcomeres bound end on end . Actin is a thin filament, about 7nm in diameter, and myosin is a thick filament, about 15nm in diameter , both of which reside in the sarcomere. They are held together by transverse bands known as Z lines . Diagram 2 shows actin and myosin filaments within a sarcomere, and the Z lines that connect them.

10. two of the main types of muscle tissue correspond with muscles that are involuntary, they are cardiac muscle, which includes the heart. Smooth muscle, which is also involuntary, and includes the stomach, intestines, uterus, urethra, bladder, and blood vessels. The Skeletal muscles are voluntary, they’re attached to the bone and are used to affect skeletal movement.

9th Ed. Boston: Benjamin Cummings, 2012. Martini, F. H., Nath, J. L., and Bartholomew, E. F. “Muscle Tissue.” Anatomy & Physiology. 9th

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.

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

[pic] Background Smooth muscle is one of three muscle fiber types found in animals. Unlike skeletal and cardiac muscle cells, smooth muscle cells are not striated, and have single nuclei. Smooth muscles are typically under control of the autonomic nervous system, and do not contract voluntarily. Smooth muscle contracts slowly,

INTRODUCTION When a muscle contracts, myosin heads in thick filaments bind to actin in thin filaments and pulls the thin filament, shortening the length of the muscle fiber. However, without Ca++ when troponin binds to actin, the tropomyosin moves into a position that

Summary… A condition which is characterized by an inability of the muscles to function at their full strength; a vague complaint of debility, fatigue, or exhaustion attributable to weakness of various muscles. The weakness can be characterized as subacute or chronic, often progressive, and is a manifestation of many muscle

1.a) Contractile protein molecules that are seen in skeletal muscle fibres are actin (thin filaments) and myosin (thick filaments). Together, they produce the force of muscle contractions by forming cross bridges, and moving via a power stroke. The regulatory proteins that are seen within a skeletal muscle are troponin and tropomyosin. These proteins play a role in starting or stopping muscle contractions. When a muscle fibre is relaxed, there are no contractions because actin is unable to bind with the cross bridge. This is because tropomyosin covers the myosin binding sites on the actin proteins. In addition, troponin is not bound to calcium when a muscle fibre is relaxed, thus keeping the tropomyosin in its blocking position. When calcium enters the muscle fibres, it binds with troponin. This binding causes the tropomyosin to move away

This table shows the similarities and differences between the cardiac and skeletal muscle. One of the main similarities is the fact both muscles are categorized as striated muscles. Striations are the main key to identifying the skeletal and cardiac muscle. The striated muscles are attached to the bone of the