Many human actions are automatic and protective, known as reflex actions.

Which two of the following are examples of reflex actions?

• Jerking your knee when tapped below the kneecap
• Contracting your biceps to lift a heavy book
• Pulling your hand away rapidly after touching a hot pan
• Deciding to put on a jacket when it feels cold
• Planning a walking route on a map

Figure 1 shows how the size of the pupil of the human eye can change by reflex action.

Draw on this

Name one stimulus that would cause the pupil to change in size from $P$ to $Q$, as shown in Figure 1.

Structure M causes the change in size of the pupil.

Name structure M.

Describe how structure M causes the change in the size of the pupil from $P$ to $Q$.

Figure 2 shows some structures involved in the coordination of a spinal reflex action.

Describe how the structures shown in Figure 2 help to coordinate a reflex action. Refer to Neurone A, Neurone B, and Neurone C in your answer.