A 60-year-old man is unable to walk more than 100 yards without experiencing severe pain in his left leg; the pain is relieved by resting for 5–10 minutes. He is told that the arteries of his leg are...

A 60-year-old man is unable to walk more than 100 yards without experiencing severe pain in his left leg; the pain is relieved by resting for 5–10 minutes. He is told that the arteries of his leg are becoming occluded with fatty material and is advised to have the sympathetic nerves serving that body region severed. Explain how such surgery might help to relieve this man’s problem.

Your friend Jillian, who knows little about science, is reading a magazine article about a patient who had an “aneurysm at the baseof his brain that suddenly grew much larger.” The surgeons’ first goal was to “keep it from rupturing,” and the second goal was to “relieve the pressure on the brain stem and cranial nerves.” The surgeons were able to “replace the aneurysm with a section of plastic tubing,” so the patient recovered. Jillian asks you what all this means. Explain. (Hint: Check this chapter’s Related Clinical Terms, p. 791.)