Jake was rabbit hunting with some friends, and accidentally got shot... (Nerves and reflexes)

Jake was rabbit hunting with some friends, and accidentally got shot with buckshot in his left thigh. At the ER, the nurse recorded that Jake could not hold his weight on that leg, and had no sensation on the posterior thigh and lower leg. The doctor tested Jake's reflexes and found his patellar reflex to be intact, but his posterior leg reflexes such as the calcaneal (Achilles) reflex were absent.

Identify which nerve was damaged and explain what information you used to determine this. Name the type of reflex that was tested, and name the components of the reflex arc for the calcaneal reflex, starting with the receptor and ending with the effector. Identify which part of the reflex arc was damaged. Identify the response to the calcaneal reflex that Jake was lacking.