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However, there is an inhibitory interneuron used to relax the antagonistic hamstring muscle (reciprocal innervation). This test of a basic automatic reflex may be influenced by the patient consciously inhibiting or exaggerating the response; the doctor may use the Jendrassik maneuver in order to ensure a more valid reflex test.
Muscles should be inserted over the knee joint, in the tibia or in the fibula. Muscles will be innervated by the tibial branch of the sciatic nerve. Muscle will participate in flexion of the knee joint and extension of the hip joint. Those muscles which fulfill all of the four criteria are called true hamstrings.
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 contain fewer muscle fibers in each motor unit. [1]
It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction. [2] Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. In the neuromuscular system, nerves from the central nervous system and the peripheral nervous system are linked and work together with muscles. [3]
Many voluntary movements rely on spinal lower motor neurons, which innervate skeletal muscle fibers and act as a link between upper motor neurons and muscles. [2] [3] Cranial nerve lower motor neurons also control some voluntary movements of the eyes, face and tongue, and contribute to chewing, swallowing and vocalization. [4]
The tongue is a composite muscle made up of various components like longitudinal, transverse, horizontal muscles with different parts innervated having different nerve supply. Digastric muscle: Its anterior belly is supplied by mylohyoid nerve (a branch of trigeminal nerve). The posterior belly is supplied by the facial nerve.
Cranial nerves: They are the nerve fibers that carry information into and out of the brain stem. [4] They include smell, eye muscles, mouth, taste, ear, neck, shoulders, and tongue. [6] Partially innervating the head and neck structures are the cranial nerves, which supply afferent and efferent functions.
At the same time, signals travel up the spinal cord and cause contraction of the contralateral muscles of the hip and abdomen to shift the body’s center of gravity over the extended leg. To a large extent, the coordination of all these muscles and maintenance of equilibrium is mediated by the cerebellum and cerebral cortex. [5]