Completely different meanings even occur in different branches of physiology, e. As a student, it is easy to despair! But the meanings of words are very precise in science: This glossary is for browsing in, testing yourself, and learning about words that catch your eye.
Muscle contraction When contracting, thin and thick filaments slide with respect to each other by using adenosine triphosphate. This pulls the Z discs closer together in a process called sliding filament mechanism. The contraction of all the sarcomeres results in the contraction of the whole muscle fiber.
This contraction of the myocyte is triggered by the action potential over the cell membrane of the myocyte. The action potential uses transverse tubules to get from the surface to the interior of the myocyte, which is continuous within the cell membrane.
Sarcoplasmic reticula are membranous bags that transverse tubules touch but remain separate from. With a singular neuromuscular junctioneach muscle fiber receives input from just one somatic efferent neuron. Action potential in a somatic efferent neuron causes the release of the neurotransmitter acetylcholine.
This initiates an impulse that travels across the sarcolemma. This causes the filaments to start sliding and the sarcomeres to become shorter. This requires a large amount of ATP, as it is used in both the attachment and release of every myosin head.
This in turn causes the muscle cell to relax. Twitch contraction is the process in which a single stimulus signals for a single contraction. In twitch contraction the length of the contraction may vary depending on the size of the muscle cell.
During treppe or summation contraction muscles do not start at maximum efficiency; instead they achieve increased strength of contraction due to repeated stimuli. Tetanus involves a sustained contraction of muscles due to a series of rapid stimuli, which can continue until the muscles fatigue.
Isometric contractions are skeletal muscle contractions that do not cause movement of the muscle. However, isotonic contractions are skeletal muscle contractions that do cause movement.
These electrical impulses coordinate contraction throughout the remaining heart muscle via the electrical conduction system of the heart. Sinoatrial node activity is modulated, in turn, by nerve fibres of both the sympathetic and parasympathetic nervous systems. These systems act to increase and decrease, respectively, the rate of production of electrical impulses by the sinoatrial node.
Fiber typing[ edit ] ATPase staining of a muscle cross section. Type II fibers are dark, due to the alkaline pH of the preparation. In this example, the size of the type II fibers is considerably less than the type I fibers due to denervation atrophy.
There are numerous methods employed for fiber-typing, and confusion between the methods is common among non-experts. Two commonly confused methods are histochemical staining for myosin ATPase activity and immunohistochemical staining for Myosin heavy chain MHC type.
Myosin ATPase activity is commonly—and correctly—referred to as simply "fiber type", and results from the direct assaying of ATPase activity under various conditions e.A myocyte (also known as a muscle cell) is the type of cell found in muscle initiativeblog.comes are long, tubular cells that develop from myoblasts to form muscles in a process known as myogenesis.
There are various specialized forms of myocytes: cardiac, skeletal, and smooth muscle cells, with various properties. The striated cells of cardiac and skeletal muscles are referred to as muscle fibers. Critical Update: How to Optimally Rotate the Pelvis during the Downswing.
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Introduction: In this review paper I will be detailing in considerable depth my updated opinions regarding the optimal method of performing a rotary pelvic motion during the downswing.
We’ve had a few comments come in this week from people struggling with their lack of progress and dissatisfaction with their size gains as compared to their strength gains..
I’ve written about this before and showed the geometric relationship between the area of a muscle and its cross-sectional size. This is a law which can’t be overcome – you will always see a disproportionate.
Human muscle system, the muscles of the human body that work the skeletal system, that are under voluntary control, and that are concerned with movement, posture, and initiativeblog.comy considered, human muscle—like the muscles of all vertebrates—is often divided into striated muscle (or skeletal muscle), smooth muscle, and cardiac initiativeblog.com muscle is under involuntary control and is.
What is the difference between Isotonic and Isometric Contraction? • In isotonic contraction, the tension is constant while the length of the muscle varies. In isometric contraction, the muscle length remains constant while the tension varies. • Isotonic twitch has a shorter latent period, shorter contraction period, and a longer relaxation.
Such clinical features as fatigue, weakness, nervousness, pain, tenderness, paralysis, sensory loss, paresthesia, and abnormalities of muscle mass or tone are the most common signs and symptoms noted in neural disorders.