Premature ventricular contraction

was stimulated by one pulse in a 625 ms period after an initial 50 ms delay, each record. The minimum stimulus voltage that resulted in a measurable muscle contraction was the threshold voltage. Records were collected until three successive stimuli of increasing voltage did not increase the force generated by the resulting muscle contractions. The stimulus voltage applied to the muscle at the point where increased voltage strength ceased to increase force generation was the maximum excitation…

The ability for muscles to contract and shorten to produce movement lies within its structure at a cellular level. The muscle organ is surrounded by a fibrous connective tissue called the epimysium, continuous to the perimysium, which separates the organ into small bundles called fascicles. Each fascicle can be further separated into muscle fibers by the endomysium. The plasma membrane of an individual muscle fiber is called the sarcolemma, which plays a major role in generating an action along…

Movement of the skeleton is stimulated by the contraction of striated muscle also known as skeletal muscle. Because it is attached to the bones and skin it is responsible for the motion of the body and limbs, thus making it controlled voluntarily. There are three layers of connective tissue in the skeletal muscle known as epimysium which surrounds the entire muscle, perimysium which surrounds muscle fibers known as fascicles, and endomysium which contains capillaries and nerve fibers. Cardiac…

control lots of muscle fiber, they can form a motor unit. When we do muscle contraction, motor units are activated to send electron signal to muscles, then muscles can do contraction. According to the different physiological function, motor unit can be divided into 2 categories, kinetic motor unit and tonic motor unit. The high frequency of electron signal released when the motor unit of the muscle fiber is excited, the contraction force is strong, but is easy to fatigue, it is the fast…

In a skeletal system joints, ligaments, and tendons all go hand in hand. A joint is defined by two or more bones that meet. However, with the use of fibrous connective tissue, ligaments allow the joints to be held together. Ligaments are what prevent us from moving in an undesirable plane, another purpose they serve is that they limit the range or extent of normal movement (Wallace 2013). Unlike ligaments where the bone might be attached to another, tendons are fibrous tissue connecting the…

Levers are needed within the body so that any small forces can be used to help the bigger forces which are needed. The muscle and bones come together to make a lever, this helps to turn a pivot joint also known as mechanic advantage. There are 4 areas of a lever such as the bone on our bones turn to lever arms, the joints turn to pivots, the muscles stimulate effort to move the force or load and the body parts give muscles strength to move what needs lifted. 1st class levers are very uncommon…

that are on the motor end plate. Then, an action potation is made and travels across the sarcolemma surface. After, the action potential travels down T Tubules. Lastly, calcium ions are released into the sarcoplasm. 3. Calcium functions to cause contraction of a skeletal muscle cell. They way it…

• Muscle tissue: Cardiac and skeletal muscle Cardiac and skeletal muscles have very few similarities and many differences. Firstly cardiac muscles location is found in the heart and the skeletal muscle location is found all over the body in every single bone present in humans. The similarities of cardiac and skeletal to start with is that they are both striated muscle structured, but cardiac is lightly striated and skeletal is heavily striated. Now to describe the differences, initially…

Muscle contraction is a process leading to the shortening and or development of tension in muscle tissue. Tension is developed in muscle tissue when muscles contract. That tension may or may not lead to movement. To contract means to shorten; however, this is not always the case in a muscle contraction. The tension may cause muscle to remain the same, elongate, or condense. When muscles decrease in length (e.x. lifting weights) it is called a concentric contraction. When muscles increase in…

Figure 1 Myosin and actin work together to generate motion within skeletal muscles, however, a vital means of communication, uniting motor neurons and muscles, must be present prior to movement. Tropomyosin and troponin maintain control over the contractions produced by myosin and actin and provide an essential outlet for dictating instructions. Tropomyosin, a two-stranded, alpha-helical coil protein, is positioned laterally along actin filaments and is responsible for “blocking” myosin heads…