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Skeletal muscle summary
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Cellular Respiration in Skeletal Muscles
Every day we use our skeletal muscle to do simple task and without skeletal muscles, we will not be able to do anything. Szent-Gyorgyi (2011) muscle tissue contraction in rabbit’s muscles and discovered that ATP is a source for muscle contraction and not ADP. He proposed a mechanism to cellular respiration and was later used by Sir Hans Krebs to investigate the steps to glucose catabolism to make ATP. In this paper, I will be discussing the structure of muscle fibers and skeletal muscles, muscle contraction, biomechanics, and how glucose and fat are metabolized in the skeletal muscles.
Muscle fibers are cylindrical. They have a diameter around ten to one hundred micrometers and are generally a few centimeters long. Within each muscle cells, contains basal lamina of collagen and glycoproteins. Each fiber contains a structure called excitation-contraction coupling, which is used to make sure the each contractile stimulus is quickly and equally communicated throughout the muscle fiber.
The four different type of fiber types are: slow, fast and fatigue resistant, fast fatigable and fast intermediate. Slow muscle fibers have a long twitch time, which means that they have low peak forces, and have a high resistance to fatigue. These fibers are high in oxidative enzymes and are low in glycolytic markers and ATP activity.
Fast and fatigue resistant fibers are faster in contractions. Fast and fatigue resistant fibers maintains force production after contractions. These fibers are the opposite of slow fibers, instead they have a high ATP and glycolytic activity and have a low oxidative capacity. The fast fatigable have high contractions rates and large forces, but they cannot maintain tensions...
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...st the sacrolemma will depolarized, thus activation potentials along the T-tubules. This signal will transmit from along the T-tubules to sarcroplasmic reticulum's terminal sacs. Next, sarcoplasmic reticulum will release the calcium into the sarcroplasm leading to the next second event called contraction. The released calcium ions will now bind to troponin. This will cause the inhibition of actin and mysoin interaction to be released. The crossbridge of myosin filaments that are attached to the actin filaments, thus causing tension to be exerted and the muscles will shorten by sliding filament mechanism. The last event is called Relaxation. After the sliding of the filament mechanism, the calcium will be slowly pumped back into the scaroplasmic reticulum. The crossbridges will detach from the filaments. The inhibition of the actin and myosin will go back to normal.
In the beginning phases of muscle contraction, a “cocked” motor neuron in the spinal cord is activated to form a neuromuscular junction with each muscle fiber when it begins branching out to each cell. An action potential is passed down the nerve, releasing calcium, which simultaneously stimulates the release of acetylcholine onto the sarcolemma. As long as calcium and ATP are present, the contraction will continue. Acetylcholine then initiates the resting potential’s change under the motor end plate, stimulates the action potential, and passes along both directions on the surface of the muscle fiber. Sodium ions rush into the cell through the open channels to depolarize the sarcolemma. The depolarization spreads. The potassium channels open while the sodium channels close off, which repolarizes the entire cell. The action potential is dispersed throughout the cell through the transverse tubule, causing the sarcoplasmic reticulum to release
Cellular respiration is the process by which energy is harvested involving the oxidation of organic compounds to extract energy from chemical bonds (Raven & Johnson, 2014). There are two types of cellular respiration which include anaerobic respiration, which can be done without oxygen, and aerobic respiration, which requires oxygen. The purpose of this experiment is to determine whether Phaseolus lunatus, also known as dormant seeds or lima beans, respire. You will compare the results of the respiration rate of the dormant seeds, and the Pisum sativum, or garden peas. In this experiment, you will use two constants which will be the temperature of the water and the time each set of peas are soaked and recorded. Using these constants will help
Kinesiology: The Mechanics & Pathomechanics of Human Movement (Second ed.). Glenside, Pennsylvania: Lippincott Williams & Wilkins. Qiao T, Liu C and Ran F. (2005) The impact of gastrocnemius muscle cell changes in chronic venous insufficiency. Eur J Vasc Endovase Surg 30; 430-436.
Within skeletal muscle there are extremely small structures that form the muscle and allow contractions and movement to occur (epimysium, perimysium, endomysium, fascicles, fiber, sarcomere, sarcoplasmic reticulum and t tubules). These structures all play a role in protecting, connecting and transporting substances throughout the muscle fibers. They are also the main contributors to movement.
Black Star, composed of MC’s Mos Def and Talib Kweli, are joined by fellow rapper Common in their 1998 song “Respiration” to expose the decaying urban and societal conditions in their respective cities of Brooklyn and Chicago. Each artist paints a brilliant picture of their surroundings and deals with various issues which plague their communities. Mos Def’s verse is particularly well-written; in it he highlights the growing economic inequality, daily struggles of the inner city poor, and the overriding nature of the his city.
The source expands on three major groups of muscular systems. They are skeletal muscle, Cardiac muscle and smooth muscle. Skeletal muscles are made up of muscle tissue, connective tissue, nerves and blood vessels that is attached to tendons and bones. Cardiac muscles are small with short wide T-tubules and is only found in heart. Smooth muscles are long, slender and spindle shaped with no T tubules, myofibrils or sarcomeres that arrange the blood vessels in some organs. All these three types of muscles are grouped together with fibers that
Cardiac muscle is a type of involuntary muscle found only in the walls of the heart, specifically the myocardium. Cardiac muscles contract automatically to tighten the walls of the heart in a rhythmic fashion. The heart beats nonstop about 100,000 times each day. Smooth muscle is a type of involuntary muscle found within the walls of blood vessels such as in small arteries and veins. Smooth muscle is also found in the urinary bladder, uterus, male and female reproductive tracts, gastrointestinal tract, and the respiratory tract. Skeletal muscles are voluntarily controlled and are attached to bones by tendons. Skeletal muscles also vary considerably in size and shape. They range from extremely tiny strands such as in the muscle of the middle ear as large like in the muscles of the thigh. The three individual muscle types also serve five main functions. The five basic functions are movement, organ protection, pumping blood, aiding digestion, and ensuring blood flow.
Sarcopenia is considered to be the degenerative loss of skeletal muscle mass and it’s functioning due to aging (Waters, Baumgartner & Garry 2000). It is linked to muscle atrophy which is shortening of the muscle. It can be mostly noticed in fast twitch fibres which usually fatigue easily and provide a larger amount of force in comparison to slow twitch fibres. Sarcopenia is usually ...
Muscle activity, including generating force and moving limbs through lengthening and shortening, is an important influence on beneficial tissue stress. Muscles adapt quickly to periods of lower or higher stress and demonstrate obvious visual and functional changes. At a tissue level, the Physical Stress Theory (PST) states that muscle adaptations are consistent with other high and low strain tissue adaptation models. Low stress/activity associated with immobilization results in decreases in contractile protein, fiber diameter, peak tension and power. Evidence supports the idea that tissues within the musculoskeletal system atrophy and become less tolerant of physical stress if stress on the tissue diminishes below a baseline level.3 In addition,
Tremblay, A., Simoneau, J., & Bouchard, C. (1994). Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism, 43(7), 814--818.
When observing both cell types under a microscope several differences are obvious. Firstly, skeletal muscles are larger than smooth muscle cells (one muscle cell can be up to 100µm in length). They are also multinucleated whilst smooth muscle cells are uninucleate (Alberts et al, 2002: 961). Additionally, skeletal muscle cells appear to be striated, whereas smooth muscle cells do not show this banding pattern; but are instead smooth and tapered. The absence of this patterning in smooth muscle cells suggests that they consist of a less organised collection of contractile fibres (Silverthorn, 2007: 397). This banding pattern in skeletal muscles is known as the sarcomere.
fibers. When ATP and is in turn broken down, the result is a spark of
From my reading I learned that cellular respiration is a multi-step metabolic reaction type process that takes place in each living organism 's cell rather it be plant or animal. It’s my understanding that there are two types of cellular respiration, one called aerobic cellular respiration which required oxygen and anaerobic cellular respiration that does not require oxygen. In the anaerobic cellular respiration process, unlike the aerobic process oxygen is not required nor is it the last electron acceptor there by producing fewer ATP molecules and releasing byproducts of alcohol or lactic acid. The anaerobic cellular respiration process starts out exactly the same as anaerobic respiration, but stops part way through due to oxygen not being
Synaptic transmission is the process of the communication of neurons. Communication between neurons and communication between neuron and muscle occurs at specialized junction called synapses. The most common type of synapse is the chemical synapse. Synaptic transmission begins when the nerve impulse or action potential reaches the presynaptic axon terminal. The action potential causes depolarization of the presynaptic membrane and it will initiates the sequence of events leading to release the neurotransmitter and then, the neurotransmitter attach to the receptor at the postsynaptic membrane and it will lead to the activate of the postsynaptic membrane and continue to send the impulse to other neuron or sending the signal to the muscle for contraction (Breedlove, Watson, & Rosenzweig, 2012; Barnes, 2013). Synaptic vesicles exist in different type, either tethered to the cytoskeleton in a reserve pool, or free in the cytoplasm (Purves, et al., 2001). Some of the free vesicles make their way to the plasma membrane and dock, as a series of priming reactions prepares the vesicular ...
Muscle tissues grow by means of physical activity in the same way they are able to become more well-defined (with regards to physical