Final answer:
The Achilles reflex tests the functioning of the nerves that control the calf muscles. It is tested by striking the tendon at the back of the ankle. When the Achilles reflex is tested, a sensory signal is sent to the spinal cord, and then a motor signal is sent back to the muscles, causing them to contract.
Step-by-step explanation:
The Achilles reflex, also known as the ankle reflex, is a test that checks the functioning of the nerves that control the calf muscles. It is a common reflex tested in the neurological exam. To test the Achilles reflex, the tendon at the back of the ankle is struck with a rubber mallet, which stretches the calf muscles. A sensory signal is sent to the spinal cord, and then a motor signal is sent back to the muscles, causing them to contract.