Q1. What time one is cold or the external temperature is low, most venous blood returning from the distal part of the arm travels in the deep veins where it picks up heat (by concurrent exchange) from the nearby brachial artery en route. Though, when one is hot, and especially during exercise, venous return from the distal arm travels in the superficial veins and those veins tend to bulge superficially in a person who is working out. Give details why venous return takes a different route in the second situation.

Q2. Due to a spinal injury, a patient has lost pain and temperature sensation on the left half of his body from the waist down. Where is his injury? Where will you expect loss of tactile sensation in this patient?