Explain when you hit the patella knee cap your reflexes jerk a little. i know that due to sending a signal to?

the spinal cord receptors. but why is the reflex greater when your hands are folded together you get a greater response????????

the knee jerk reflex, is caused by stretch in your guadriceps. there are receptors in the tendon that sense stretch of the tendon and send messages, as you said, to the spinal cord. The spinal cord then tells the quads to tighten so the tendon doesn't become too stretched and break. Now the hand position, what that does is distract the person from controlling the muscles. The reflex is unconscious but can be overriden if you think about it, so doctors try to make you think about holding your arms together so you aren't impeding your reflex

The knee jerk reflex is supplied by the L3 and L4 nerve roots.

The examiner:

* slides his one arm under the patient's knees so they are supported and slightly bent
* lets the tendon hammer fall onto the infrapatellar tendon
* an intact reflex arc results in contraction of quadriceps and extension of the knee

If the reflexes appear to be absent then ask the patient to interlock his fingers and then to pull them hard apart or clench their teeth- 'reinforcement'. While the patient is doing this, the examiner tests for the reflexes again.

Reinforcement may be needed to relax the patients muscles and joint by distraction