MUSCULAR CONTRACTION Meaning and
Definition
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Muscular contraction refers to the physiological process in which muscle fibers generate tension through the activation of actin and myosin proteins within the muscle cells. It is a complex event that allows muscles to exert force and produce movement.
During a muscular contraction, nerve impulses from the brain or spinal cord stimulate the motor neurons, which in turn activate the muscle fibers. This electrical signal triggers the release of calcium ions from the sarcoplasmic reticulum, a network of tubules within the muscle cells. The calcium ions bind to the troponin molecules, causing the tropomyosin to shift its position and expose the binding sites on the actin filaments.
Once the binding sites become available, the myosin heads, present on the thick filaments of the muscle fibers, can connect to the actin and form cross-bridges. By using the energy from ATP (adenosine triphosphate) hydrolysis, the myosin heads pull the actin filaments towards the center of the sarcomere, producing a sliding movement. This slide generates tension as the sarcomeres, the basic contractile units of muscles, shorten.
Muscular contraction can be categorized into two types: isotonic and isometric contractions. Isotonic contraction occurs when the tension generated by the muscles remains relatively constant, and the length of the muscle changes. This is observed during movements such as walking or lifting objects. On the other hand, isometric contraction happens when the tension develops within the muscle, but there is no change in its length. This type of contraction is noticeable when holding a heavy object without moving it.
In summary, muscular contraction is the process by which muscle fibers generate tension and produce movement, allowing an organism to perform various motor activities. It involves a series of
Common Misspellings for MUSCULAR CONTRACTION
- nuscular contraction
- kuscular contraction
- juscular contraction
- myscular contraction
- mhscular contraction
- mjscular contraction
- miscular contraction
- m8scular contraction
- m7scular contraction
- muacular contraction
- muzcular contraction
- muxcular contraction
- mudcular contraction
- muecular contraction
- muwcular contraction
- musxular contraction
- musvular contraction
- musfular contraction
- musdular contraction
Etymology of MUSCULAR CONTRACTION
The term "muscular contraction" is composed of two main parts: "muscular" and "contraction".
1. Muscular: The word "muscular" originates from the Latin term "musculus", which means "a muscle". This Latin word is a diminutive form of "mus", meaning "mouse". It is believed that this term was chosen due to the shape and movement of muscles resembling the movement of mice. Over time, "musculus" evolved into "muscularis" in Medieval Latin, and eventually turned into the English word "muscular".
2. Contraction: The word "contraction" comes from the Latin verb "contrahere", which means "to draw together" or "to shrink". This word is formed by combining the prefix "con-" (meaning "together") and the verb "trahere" (meaning "to draw" or "to pull").
Similar spelling word for MUSCULAR CONTRACTION
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