Spinal level of the patellar reflex?

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Multiple Choice

Spinal level of the patellar reflex?

Explanation:
The patellar reflex is a stretch reflex whose spinal center is at the L4 level. When the patellar tendon is tapped, the quadriceps muscle spindle is stretched, sending afferent signals via the femoral nerve into the spinal cord at L4. These signals synapse directly on an alpha motor neuron in the L4 ventral horn, which, through the femoral nerve, causes the quadriceps to contract and the knee to extend. The knee-jerk reflex therefore mainly evaluates the L4 motor neuron pool. In comparison, the ankle (Achilles) reflex tests S1–S2, so those levels are not the primary contributors to the patellar reflex.

The patellar reflex is a stretch reflex whose spinal center is at the L4 level. When the patellar tendon is tapped, the quadriceps muscle spindle is stretched, sending afferent signals via the femoral nerve into the spinal cord at L4. These signals synapse directly on an alpha motor neuron in the L4 ventral horn, which, through the femoral nerve, causes the quadriceps to contract and the knee to extend. The knee-jerk reflex therefore mainly evaluates the L4 motor neuron pool. In comparison, the ankle (Achilles) reflex tests S1–S2, so those levels are not the primary contributors to the patellar reflex.

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