Search results
Results from the WOW.Com Content Network
In vertebrates, the force of a muscle contraction is controlled by the number of activated motor units. The number of muscle fibers within each unit can vary within a particular muscle and even more from muscle to muscle: the muscles that act on the largest body masses have motor units that contain more muscle fibers, whereas smaller muscles ...
The uvula (pl.: uvulas or uvulae), also known as the palatine uvula or staphyle, is a conic projection from the back edge of the middle of the soft palate, composed of connective tissue containing a number of racemose glands, and some muscular fibers. [1] [2] It also contains many serous glands, which produce thin saliva. [3] It is only found ...
All muscles consist of a number of motor units and the fibers belonging to a motor unit are dispersed and intermingle amongst fibers of other units. The muscle fibers belonging to one motor unit can be spread throughout part, or most of the entire muscle, depending on the number of fibers and size of the muscle.
Resistance training has been shown to dramatically increase performance of motor units of the larger muscle groups. [2] Motor unit plasticity of the larger muscle groups is extremely important for athletes, especially those participating in high impact and fast pace sports such as track and field, martial arts, and American football.
These attach to and control discrete bundles of muscle fibers. A coordinated and fine-tuned response to a specific circumstance will involve controlling the precise number of motor units used. While individual muscle units' contract as a unit, the entire muscle can contract on a predetermined basis due to the structure of the motor unit.
Human ancestors are thought to have had more muscles connecting the skull, neck, and shoulders/back area (similar to apes) which caused their neck and skull regions to appear to sag, such as non-human primate species do. These diminished muscles allow the human head to be held in its current ‘upright’ position and lets the occipitofrontalis ...
In some of its facets human anatomy is closely related to embryology, comparative anatomy and comparative embryology, [1] through common roots in evolution; for example, much of the human body maintains the ancient segmental pattern that is present in all vertebrates with basic units being repeated, which is particularly obvious in the ...
The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs. [3]