"Well, the parathyroid gland is like a 24 hour calcium monitor, when the gland detects that blood calcium levels have dropped under a certain amount, they produce PTH."
A thermostat is sensitive to and responds to the temperature in a room. This gland is sensitive to the level of calcium in the blood and will respond to fluctuation in this ion.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.