A- Reaction time in a spinal reflex is usually shorter than in a voluntary respo

Question

A- Reaction time in a spinal reflex is usually shorter than in a voluntary response. Did your data corborate this observation (provide a quantitative answer)? Why would reflexes be faster than voluntary responses?( explain the mechanisms that account for the difference?)
B- The jendrassik maneuver may exaggerate spinal reflexes such as the patellar reflex. a- is this consistent with your observations? why would it happen?
b- if you didn't observe it, what might have affected your results?
c- Did you see a correlation between the force of the reflex hammer strike and the magnitude of the reflexive response? Was the relationship affected by the jendrassik maneuver or doing mental math? Date: Data and Calculations (1 pt) ubject Profile Name Age Gender: Male/Female Height Weight PART 1-VOLUNTARY REACTIONS A. Summary of Individual Subject's Results Table 1 Stimulus number Reaction time (ms) Dominant Reaction time (ms) Non-dominant Fixed interval 22 0 80 54 68 Random 229 Fixed interval Random 244 75 175 8 201 215 165 Bol 165 214 153 144 289 19 84 1 58 1 60 156 286 215 83 10 Mean 16 114.2 280.2 203.6

Explanation / Answer

A. Voluntary reactions are initiated in the cerebral cortex of brain while reflexes are initiated by the stimulation of receptors; which could either be visual, olfactory, audible or gustatory in nature. A reflex is faster than the voluntary reactions because of the complexity of the neural pathway through which the reaction occurs. The nerve diameter and myelination determines the speed of the nerve conduction velocity i.e., the speed at which the nerve impulse travels along the neural pathway. In voluntary responses, the nerve impulse passes to the side of the cerebral cortex and then down the motor neuron through the spinal cord. Here the impulse first has to travel to the brain and then the response is sent back to the muscles though spinal cord.The impulse passes to the opposite side of the body as right side of the brain controls the left side of the body and vice versa. This involves a lot of cells and synapses and thus a longer pathway making voluntary responses comparitively slower to the reflexes. In reflex responses, the stimulus travels only to the grey matter near to the centre of the spinal cord and then to the motor neuron. The stimulus along with the action and the neurons involved are all on the same side of the body which makes them faster compared to voluntary responses.

B.a) The flexor time is increasing with the decrease in the strike force.Paying attention to the reflexes intends to reduce the amplitude of the reflexes.

b) In the second table, with the increase in the strike force, the reflexes and the voluntary responses are increasing with time. But, in this case, the mental math is also consistently increasing.Paying attention to the reflexes intends to reduce the amplitude of the reflexes.

c) Mental math was provided to create a distraction during the jendrassik manouver. The distraction was supposed to allow the reflexes to be precise and quick to the strike of the hammer. But paying attention to the strike or the reflexes might affect the experiment.All the aspects have been increasing consistently in the second table. But in the third table we can observe that the higher the strike force, the quicker the reflex is.But the mental math is again increasing consistently irrespective of the magnitude of the strike force and the response.

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