You’re doing a clinical at the local hospital when you meet Mr. T, a 23-year-old man who has suffered a complete spinal injury at the level of the third thoracic vertebra in a motorcycle accident. He’s been recovering uneventfully for three days when his sister comes to visit him. She hasn’t been in the room long when she comes running out, calling for help. When you go in, you see Mr. T lying unconscious in bed. His face and arms are pale, cold, and sweating, and the monitor attached to his arm blood pressure cuff says his heart rate is elevated and his blood pressure is dangerously low. His blanket is off, and his legs are flushed a bright pink and warm to the touch. You immediately lower the head of the bed, and Mr. T’s blood pressure starts to rise. In a few moments he opens his eyes, and soon he’s able to tell you what happened. While chatting with his sister, Mr. T asked her to raise the head of his bed. As soon as she did that, he started to feel faint and it just got worse and worse until he passed out. When Mr. T’s blood pressure dropped, his heart rate increased. Which part of his autonomic system was responsible for this response? What other signs of autonomic activity did you observe in Mr. T?