Search results
Results from the WOW.Com Content Network
reticulospinal tract: connects the reticular system, a diffuse region of gray matter in the brain stem, to the spinal cord. It also contributes to muscle tone and influences autonomic functions. lateral vestibulospinal tract: Connects the brain stem nuclei of the vestibular system with the spinal cord. This allows posture, movement, and balance ...
The muscular system is an organ system consisting of skeletal, smooth, and cardiac muscle. It permits movement of the body, maintains posture, and circulates blood throughout the body. [1] The muscular systems in vertebrates are controlled through the nervous system although some muscles (such as the cardiac muscle) can be
To generate more force, increase the spike rates of active motor neurons and/or recruiting more and stronger motor units. In turn, how the muscle force produces limb movement depends on the limb biomechanics, e.g. where the tendon and muscle originate (which bone, and precise location) and where the muscle inserts on the bone that it moves.
The cell bodies of Betz cell neurons are the largest in the brain, approaching nearly 0.1 mm in diameter. The axons of the upper motor neurons project out of the precentral gyrus travelling through to the brainstem, where they will decussate (intersect) within the lower medulla oblongata to form the lateral corticospinal tract on each side of ...
A functional muscle synergy is defined as a pattern of co-activation of muscles recruited by a single neural command signal. [18] One muscle can be part of multiple muscle synergies, and one synergy can activate multiple muscles. Synergies are learned, rather than being hardwired, like motor programs, and are organized in a task-dependent manner.
Muscle relaxation and inhibition of muscle contraction in vertebrates is obtained only by inhibition of the motor neuron itself. This is how muscle relaxants work by acting on the motor neurons that innervate muscles (by decreasing their electrophysiological activity) or on cholinergic neuromuscular junctions, rather than on the muscles themselves.
Reciprocal innervation describes skeletal muscles as existing in antagonistic pairs, with contraction of one muscle producing forces opposite to those generated by contraction of the other. For example, in the human arm, the triceps acts to extend the lower arm outward while the biceps acts to flex the lower arm inward. To reach optimum ...
The clearest example of the coordination of muscles into complex movement in the motor cortex comes from the work of Graziano and colleagues on the monkey brain. [ 11 ] [ 26 ] They used electrical stimulation on a behavioral time scale, such as for half a second instead of the more typical hundredth of a second.