State the name of cell P.
State the kinds of blood vessel labelled Q, S and T.
State the name of the tissue at R that acts as insulation.
Use the information in Fig. 4.2 to describe how raising the temperature of the skin surface affects blood flow to the skin without capsaicin.
Explain the mechanism that increases blood flow through the skin.
State the difference between the mean blood flow for the two treatments (with and without capsaicin) at $35\,^{\circ}\mathrm{C}$. Show your working.
The researchers believed that capsaicin stimulates receptors in the skin. Explain how capsaicin could reach these receptors.
Explain why regulating body temperature is important in humans.
Explain how co-ordination by hormones is different from co-ordination by nerves.