Search results
Results from the WOW.Com Content Network
The gastrocnemius muscle is heterogeneous, composed of both "red" and "pale" muscle, and thus containing fast-twitch high force fibers. Henneman's and colleagues took advantage of the differences between the soleus and gastrocnemius muscles to show that the neurons innervating the soleus muscle:
Muscles which possess more motor units (and thus have greater individual motor neuron innervation) are able to control force output more finely. Motor units are organized slightly differently in invertebrates : each muscle has few motor units (typically less than 10), and each muscle fiber is innervated by multiple neurons, including excitatory ...
Each individual muscle fiber is innervated by only one motor neuron, but one motor neuron may innervate several muscle fibers. This distinction is physiologically significant because the size of a given motor pool determines the activity of the muscle it innervates: for example, muscles responsible for finer movements are innervated by motor ...
The firing of gamma motor neurons in sync with alpha motor neurons pulls muscle spindles from polar ends of the fibers as this is where gamma motor neurons innervate the muscle. The spindle is innervated by type Ia sensory fiber that go on to synapse with alpha motor neurons, completing the gamma-loop. The parallel pulling keeps muscle spindles ...
A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch. Innervation takes place at a neuromuscular junction and twitches can become superimposed as a result of summation or a tetanic contraction. Individual twitches can become indistinguishable ...
There are 43 segments of nerves in the human body. [4] With each segment, there is a pair of sensory and motor nerves. 31 segments of nerves are in the spinal cord and 12 are in the brain stem. [4] Interneurons also known as association neurons are present throughout the central nervous system forming links between the sensory and motor fibres. [5]
For example, the biceps brachii muscle, a muscle of the arm, is innervated by α-MNs in spinal cord segments C5, C6, and C7, which are found rostrally in the spinal cord. On the other hand, the gastrocnemius muscle, one of the muscles of the leg, is innervated by α-MNs within segments S1 and S2, which are found caudally in the spinal cord.
The largest nerve of the human body, the sciatic nerve, is the main branch that gives rami to the motor innervation of the muscles of the thigh, the leg, and the foot. Common peroneal nerve and its branches innervate some parts of the skin of the foot, the peroneal muscles of the leg, and the dorsal muscles of the foot.