Search results
Results from the WOW.Com Content Network
In geometry, a rhombohedron (also called a rhombic hexahedron [1] [2] or, inaccurately, a rhomboid [a]) is a special case of a parallelepiped in which all six faces are congruent rhombi. [3] It can be used to define the rhombohedral lattice system , a honeycomb with rhombohedral cells.
There are two rhomboid muscles on each side of the upper back: [1] [2] [3] Rhomboid major muscle; Rhomboid minor muscle; The large rhombus-shaped muscle, located under the trapezius muscle, in the upper part of the thoracic region of the back, and the small muscle, in the same way, participate in the movement of the scapula. [4]
In either case, there are 3 lattice points per unit cell in total and the lattice is non-primitive. The Bravais lattices in the hexagonal crystal family can also be described by rhombohedral axes. [4] The unit cell is a rhombohedron (which gives the name for the rhombohedral lattice). This is a unit cell with parameters a = b = c; α = β = γ ...
The parallel muscle architecture is found in muscles where the fibers are parallel to the force-generating axis. [1] These muscles are often used for fast or extensive movements and can be measured by the anatomical cross-sectional area (ACSA). [3] Parallel muscles can be further defined into three main categories: strap, fusiform, or fan-shaped.
The muscle cross-sectional area (blue line in figure 1, also known as anatomical cross-section area, or ACSA) does not accurately represent the number of muscle fibers in the muscle. A better estimate is provided by the total area of the cross-sections perpendicular to the muscle fibers (green lines in figure 1).
More complicated aggregations have also been observed, such as rhombohedral, tetragonal and orthorhombic phases. It forms an important part of current academic research in the fields of membrane biophysics (polymorphism), biochemistry (biological impact) and organic chemistry (synthesis).
In that study, an increase in muscle fiber conduction velocity was observed when there was a higher level of voluntary muscle contraction, which agrees with the gradual recruitment of higher-force muscle types. [16] In Wistar rats, it was found that cell size is the crucial property in determining neuronal recruitment. [17]
Smooth muscle is involuntary and found in parts of the body where it conveys action without conscious intent. The majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food, chyme, and feces in the former and urine in the latter.