Spinal Reflex


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Related to Spinal Reflex: cranial reflex

spinal reflex

[′spīn·əl ′rē‚fleks]
(neuroscience)
A reflex mediated through the spinal cord without the participation of the more cephalad structures of the brain or spinal cord.

Spinal Reflex

 

a reflex whose center is located in the spinal cord. There are four types of spinal reflexes: somatic (motor), autonomic, segmental, and intersegmental. Somatic spinal reflexes are involved in the activity of the skeletal musculature of the trunk and extremities, and autonomic spinal reflexes in the activity of the musculature of the blood vessels and internal organs. Segmental spinal reflexes occur within a single segment of the spinal cord, and intersegmental spinal reflexes enter and emerge from different spinal segments.

Depending on the structure of the reflex arcs, spinal reflexes may be monosynaptic or polysynaptic. The former include tendon and muscular reflexes, including the quadriceps and triceps reflexes (extension of the extremities upon tapping a tendon). The latter include skin reflexes, for example, the flexion reflex (the jerking of an extremity in response to stimulation of the skin), reflex stepping (the extension of the leg upon touching the plantar surface), crossed reflexes of corresponding extremities, and interextremital reflexes, which are elements of locomotion, a complex motor activity. Vascular, bladder, and rectal reflexes are spinal reflexes of the internal organs.

The study of spinal reflexes is an important method used in examining individuals suffering various pathological conditions.

REFERENCES

See references under .

P. A. KISELEV

References in periodicals archive ?
This reciprocal pattern of motor disorder, extensor spasticity, and flexor weakness is a direct expression of the abnormal balance of spinal reflexes affected by chronic lesions of the higher centers, which involve amongst others the descending pathways, the corticospinal or pyramidal tract.
Stein, "Spinal reflexes in ankle flexor and extensor muscles after chronic central nervous system lesions and functional electrical stimulation," Neurorehabilitation and Neural Repair, vol.
Although previous studies have demonstrated neuro-plasticity with dance training, to date no studies have examined the role of specific presynaptic mechanisms in modulating spinal reflexes in dancers.
Answers: 1) central nervous system; 2) spinal reflex; 3) spinal cord; 4) vertebrae; 5) periphery; 6) spinal column
Key search words included, vibration and whole-body vibration; which were used in combination with spinal reflexes, muscle tuning, neuromuscular (motor unit firing frequency, synchronisation, intermuscular coordination) and central motor command.
Autogenic inhibition means "self-generated inhibition." It is the name given to the spinal reflex response that occurs when the Golgi tendon organ receptor is activated, then producing an inhibitory response in the motor neurons that return to the same muscle and its synergists.
Additionally, electrical stimulation can partially restore segmental spinal reflex responses in the lumbar spinal cord, in particular the H reflex [133], that are altered by thoracic SCI [134].
Dr A said these could be explained by spinal reflexes, and some responses could actually be seizures - "without anybody recognising them as such".
When the team tried the technique in patients, certain spinal reflexes returned, indicating that the implanted neuron had integrated with the spine to form a functional neural circuit.
But the baby revived by himself 90 minutes later, despite medical staff dismissing his breath sounds as "postdeath agonal gasps"and "spinal reflexes."
Also, shivering has been reported in normothermic patients suggesting that inhibited spinal reflexes, apprehension, decreased sympathetic activity, pyrogen release, adrenal gland suppression and respiratory alkalosis are also involved.
In summary increase in the excitability of polysynaptic spinal reflexes and startle responses was recorded, whereas other segmental and brain stem reflexes were normal.