Answer:
The nerves
Step-by-step explanation:
The blood has a pure physical function.
Alveoli are tiny air sacks in the lungs.
Capillaries are tiny blood vessels, they transfer nutrients and oxigen.
The nerves transmit impulses of sensation to the brain or spinal cord; then these impulses are sent to the muscles and organs. So if you watch something loaded with emotion, your eyes send signals to your brain which sends it to your skin that produces Goosebumps.