Search results
Results from the WOW.Com Content Network
Isotonic contractions differ from isokinetic contractions in that in isokinetic contractions the muscle speed remains constant. While superficially identical, as the muscle's force changes via the length-tension relationship during a contraction, an isotonic contraction will keep force constant while velocity changes, but an isokinetic ...
The list below describes such skeletal movements as normally are possible in particular joints of the human body. Other animals have different degrees of movement at their respective joints; this is because of differences in positions of muscles and because structures peculiar to the bodies of humans and other species block motions unsuited to ...
during contraction, actin filaments move into the A bands and the H zone is filled up reducing its stretch, the I bands shorten, the Z line comes in contact with the A bands; and; the possible driving force of contraction is the actin-myosin linkages which depend on ATP hydrolysis by the myosin.
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]
Number of times that the named muscle row occurs in a standard human body. Here it may also be denoted when a given muscles only occurs in a male or a female body. By (F) for female and (M) for male, if nothing is denoted. The muscle can be assumed to occur in both genders.
It is typically used to describe the contraction properties of pennate muscles. [1] It is not the same as the anatomical cross-sectional area (ACSA), which is the area of the crossection of a muscle perpendicular to its longitudinal axis. In a non-pennate muscle the fibers are parallel to the longitudinal axis, and therefore PCSA and ACSA coincide.
[14] For example, with the latissimus dorsi muscle, the origin site is the torso, and the insertion is the arm. When this muscle contracts, normally the arm moves due to having less mass than the torso. This is the case when grabbing objects lighter than the body, as in the typical use of a lat pull down machine.
The angle of pennation will increase during contraction accompanied by an increase in thickness. Thickness is defined as the area between the aponeuroses of the muscle. A low gear ratio occurs when the contraction velocity of the whole muscle and individual fibers is approximately the same, resulting in a gear ratio of 1.