Load reflex

Muscle spindles are intrafusal mechanoreceptors that are widely distributed within skeletal muscle fibers in the belly of the muscle. They exist in parallel with the much larger extrafusal skeletal muscle fibers, and the cotmective tissue around the muscle spindles is continuous with the connective tissue around the other muscle fibers. The muscle spindles mediate a response to a load placed on the muscle this is known as the load reflex. Muscle spindles have a dampening function, as well. They prevent some types of oscillation and jerkiness in body movement. In fact, tremors noted, especially during times of extreme anxiety or stimulation, represent a failure to dampen this response smoothly. In addition to serving at a subconscious level, the muscle spindle reflex is invoked in voluntary motor activity. 

Adults. 3 g PO q6h x 4 PRN Supl 1-2 g IM or IV repeat PRN Preeclampsia/pre-mature labor 4 g load then g/h IV inf Cardiac arrest 1-2 g IV push (2-4 mL 50% soln) in 10 mL DjW AMI Load 1-2 g in 50-100 mL D5W, over 5-60 min IV then 0.5-1.0 g/h IV up to 24 h (ECC 2005) Feds. 25-50 mg/kg/dose IM or IV q4-6h for 3-4 doses repeat PRN dose w/ low urine output or renal insuff Caution [B, +] Contra Heart block, renal failure Disp Inj 10, 20, 40, 80, 125, 500 mg/mL bulk powder SE CNS depression, D, flushing, heart block Interactions T CNS depression W/ antidepressants, antipsychotics, anxiolytics, barbiturates, hypnotics, narcotics EtOH T neuromuscular blockade Wf aminoglycosides, atracurium, gallamine, pancuronium, tubocurarine, vecuronium EMS Check for absent patellar reflexes this may indicate tox may cause hypokalemia (flattened T waves) and hypocalcemia OD May cause hypotension, resp arrest, T PR, QRS, and QT interval, AV block, and cardiac arrest calcium salts can be given to reverse resp depression... 

Hypokalemic periodic paralysis is a rare complication of hyperthyroidism commonly observed in Asian and Hispanic populations. It presents as recurrent proximal muscle flaccidity ranging from mild weakness to total paralysis. The paralysis may be asymmetric and usually involves muscle groups that are strenuously exercised before the attack. Cognition and sensory perception are spared, whereas deep tendon reflexes are commonly markedly diminished. Hypokalemia results from a shift of potassium from extracellular to intracellular sites. High carbohydrate loads and exercise provoke the attacks. Treatment includes correcting the hyperthyroid state, potassium administration, spironolactone to conserve potassium, and propranolol to minimize intracellular shifts. ... 

Mutoh T, Bonham AC, load JP (2000) Substance P in the nucleus of the solitary tract augments bronchopulmonary C fiber reflex output. Am J Physiol Regul Integr Comp Physiol 279 R1215-R1223... 

Bonham AC, Chen CY, Mutoh T, load JP (2001) Lung C-flber CNS reflex Role in the respiratory consequences of extended environmental tobacco smoke exposure in young guinea pigs. Environ Health Perspect 109(Suppl 4) 573-578... 

Bonham AC, Chen CY, Sekizawa S, load JP (2006a) Plasticity in the nucleus tractus solitarius and its influence on lung and airway reflexes, J Appl Physiol 101 322-327 Bonham AC, Sekizawa S, Chen CY, load JP (2006b) Plasticity of brainstem mechanisms of cough, Respir Physiol Neurobiol 152 312-319... 

Pole trailers shall have on the rearmost support for the load (1) two front clearance lamps, one on each side of the vehicle, both on the same level and as high as practicable to indicate the overall width of the pole trailer (2) two rear clearance lamps, one on each side of the vehicle, both on the same level and as high as practicable to indicate the overall width of the pole trailer (3) two rear side marker lamps, one on each side of the vehicle, both on the same level, not less than 375 mm (15 inches) above the road surface (4) two rear reflex reflectors, one on each side, both on the same level, not less than 375 mm (15 inches) above the road surface to indicate maximum width of the pole trailer and (5) one red reflector on each side of the rearmost support for the load. Lamps and reflectors may be combined as allowed in 393.22. 

Kyberd and Chappell (1994) use a system they call hierarchical artificial reflexes to automate the control process. In their multifunctional hand, they take the operator out of Ihe loop and use onboard processing and sensors in the hand to tell die hand what grasp pattern to adopt. The operator only provides a conventional single degree of freedom open or close EMG signal. The idea is that by allowing the processor to take control, it reduces the mental loading on the operator. A major factor in the success or failure of these devices is confidence in the mechanism on the part of the user, so as to relinquish control to the artificial reflex. 

---