Search results
Results From The WOW.Com Content Network
Depiction of smooth muscle contraction. Muscle contraction is the activation of tension -generating sites within muscle cells. [ 1][ 2] In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as when holding something heavy in the same position. [ 1]
Sliding filament theory: A sarcomere in relaxed (above) and contracted (below) positions. The sliding filament theory explains the mechanism of muscle contraction based on muscle proteins that slide past each other to generate movement. [ 1] According to the sliding filament theory, the myosin ( thick filaments) of muscle fibers slide past the ...
Blue = troponin C; green = troponin I; magenta = troponin T. [ 1] Troponin, or the troponin complex, is a complex of three regulatory proteins ( troponin C, troponin I, and troponin T) that are integral to muscle contraction [ 2] in skeletal muscle and cardiac muscle, but not smooth muscle. Measurements of cardiac-specific troponins I and T are ...
The Golgi tendon organ ( GTO) (also called Golgi organ, tendon organ, neurotendinous organ or neurotendinous spindle) is a proprioceptor – a type of sensory receptor that senses changes in muscle tension. It lies at the interface between a muscle and its tendon known as the musculotendinous junction also known as the myotendinous junction. [ 1]
Neuromuscular junction. A neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber. [ 1] It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction . Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy.
Muscle spindles are found within the belly of a skeletal muscle. Muscle spindles are fusiform (spindle-shaped), and the specialized fibers that make up the muscle spindle are called intrafusal muscle fibers. The regular muscle fibers outside of the spindle are called extrafusal muscle fibers. Muscle spindles have a capsule of connective tissue ...
An induction shock produces a contraction or fails to do so according to its strength; if it does so at all, it produces the greatest contraction that can be produced by any strength of stimulus in the condition of the muscle at the time. This principle was later found to be present in skeletal muscle by Keith Lucas in 1909. [1]
Skeletal muscle, with myofibrils labeled at upper right. A myofibril (also known as a muscle fibril or sarcostyle) [ 1] is a basic rod-like organelle of a muscle cell. [ 2] Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. [ 3] Each myofibril has a diameter of 1–2 ...