sarcomere


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

sarcomere

 [sahr´ko-mēr]
the contractile unit of a myofibril; sarcomeres are repeating units, delimited by the Z bands along the length of the myofibril.
Thick and thin filaments are organized into contractile units called sarcomeres. A sarcomere extends from one Z line to the next and represents the fundamental unit of muscle contraction. From Copstead, 1995.

sar·co·mere

(sar'kō-mēr),
The segment of a myofibril between two adjacent Z lines, representing the functional unit of striated muscle.
[sarco- + G. meros, part]

sarcomere

(sär′kə-mîr′)
n.
One of the repeating contractile segments into which a myofibril is divided, composed of actin and myosin filaments and giving striated muscle its distinctive bands.

sar·co·mere

(sahr'kō-mēr)
The segment of a myofibril between two adjacent Z lines, representing the functional unit of striated muscle.
[sarco- + G. meros, part]

sarcomere

The structural unit of a striped muscle fibre (myofibril).
Sarcomereclick for a larger image
Fig. 273 Sarcomere . Muscle fibrils consist of alternating groups of the thick and thin filaments (dark and light bands), the distance between two Z-membranes being termed a ‘sarcomere’.

sarcomere

that part of the muscle fibre which is contained between two Z-MEMBRANES, and is the contractile element of the fibre.

See MUSCLE, I-BAND.

References in periodicals archive ?
In the above-mentioned simulating model, when we slided actin filaments present on both sides of a myosin filament toward center of A band in a single sarcomere as it occurs during contraction, two Z discs on either side of A band moved toward center of the sarcomere, as shown in Figure 1.
The speed of sarcomere shortening as well as relengthening showed the same frequency relationship as the sarcomere-shortening amplitude.
For example, electrical stimulation can improve functional maturation (action potential, calcium transient, and contraction force), while mechanical stretch increases cell size and sarcomere structure.
It can be assumed that when a muscle is contracting and working just concentrically, the rate that all of the muscle's sarcomeres collectively can or are allowed to generate mechanical energy, and apply or transfer it via attached tendons and skeletal segments to an external load ultimately determines how quickly the muscle develops force and how well it maintains a useful level of force against a moving load if loading velocities reach relatively high rates and the energy is being transferred to the load at relatively high rates.
The sarcomere length of animals that received palm kernel cake decreased linearly (p<0.05; Table 5).
In 18-hour mechanically ventilated rats (PEEP of 2.5 cm H2O), diaphragm fibers adapted to the reduced length by absorbing serially linked sarcomeres, the smallest contractile units in muscle (i.e., longitudinal atrophy).
Carybdea marsupialis tentacle muscles lack Z-disks characteristic of a typical sarcomere structure but do possess light and dark myofilament bands.
We assumed baseline euvolemia for calculating the resting sarcomere length and that the volume infused did not accumulate in the RV.
In its most simplistic form, this length-tension relationship in skeletal muscle is predicated on the magnitude of overlap between actin and myosin filaments within the muscle tissue, which directly reflects a precise sarcomere length-tension relationship.
The two sub-types of HCM share the same underlying genetic defects in the sarcomere that results in hypercontractility.
Ultrastructural analysis showed swollen sarcoplasmic reticulum, dilated t tubes and areas with sarcomere disruption (Figure 4e).
The genetic defects most commonly associated with LVNC are of the sarcomere genes which are also involved with both dilated and hypertrophic cardiomyopathies [8].