The diagram shows a simplified schematic of blood vessels near the surface of the human skin, which are involved in thermoregulation.
During a period of cold exposure, thermoreceptors detect a drop in temperature and trigger autonomic reflexes to minimise heat loss.
Which row in the table below correctly describes the states of arteriole P P\,P and shunt vessel QQQ, and the resulting relative rate of blood flow through the capillary network R R\,R under these cold conditions?
State of arteriole PState of shunt vessel QBlood flow through capillary network RAConstrictedDilatedDecreasedBDilatedConstrictedIncreasedCConstrictedConstrictedDecreasedDDilatedDilatedIncreased \begin{array}{cccc} \hline & \textbf{State of arteriole } P & \textbf{State of shunt vessel } Q & \textbf{Blood flow through capillary network } R \\ \hline \mathbf{A} & \text{Constricted} & \text{Dilated} & \text{Decreased} \\ \mathbf{B} & \text{Dilated} & \text{Constricted} & \text{Increased} \\ \mathbf{C} & \text{Constricted} & \text{Constricted} & \text{Decreased} \\ \mathbf{D} & \text{Dilated} & \text{Dilated} & \text{Increased} \\ \hline \end{array} ABCDState of arteriole PConstrictedDilatedConstrictedDilatedState of shunt vessel QDilatedConstrictedConstrictedDilatedBlood flow through capillary network RDecreasedIncreasedDecreasedIncreasedRow A
Row B
Row C
Row D
