The poet Callimachus locates the Cyclopes forge on the island of Lipari, the largest of the Aeolians. Virgil associates both the Hesiodic and the Homeric Cyclopes with Sicily. He has the thunderbolt makers: "Brontes and Steropes and bare-limbed Pyracmon", work in vast caverns extending underground from Mount Etna to the island of Vulcano, while the Cyclops brethren of Polyphemus live on Sicily where "near at hand Aetna thunders".As Thucydides notes, in the case of Hephaestus forge on Vulcano, locating the Cyclopes forge underneath active volcanoes provided an explanation for the fire and smoke often seen rising from them. Etymology
For the ancient Greeks the name "Cyclopes" meant "Circle-eyes" or "Round-eyes", derived from the Greek kúklos ("circle") and ops ("eye"). This meaning can be seen as early as Hesiods Theogony  (8th–7th century BC), which explains that the Cyclopes were called that "since a single circle-shaped eye was set in their foreheads". Adalbert Kuhn, expanding on Hesiods etymology, proposed a connection between the first element kúklos (which can also mean "wheel") and the "wheel of the sun", producing the meaning "wheel (of the sun)-eyes". Other etymologies have been proposed which derive the second element of the name from the Greek klops ("thief") producing the meanings "wheel-thief" or "cattle-thief". Although Walter Burkert has described Hesiods etymology as "not too attractive", Hesiods explanation still finds acceptance by modern scholars. Possible origins
A possible origin for one-eyed Cyclopes was advanced by the palaeontologist Othenio Abel in 1914.
Muscarinic receptors are coupled to the Gi subunit; therefore, vagal activation decreases cAMP. Gi-protein activation also leads to the activation of KACh channels that increase potassium efflux and hyperpolarizes the cells. Increases in vagal activities to the SA node decreases the firing rate of the pacemaker cells by decreasing the slope of the pacemaker potential (phase 4 of the action potential); this decreases heart rate (negative chronotropy). The change in phase 4 slope results from alterations in potassium and calcium currents, as well as the slow-inward sodium current that is thought to be responsible for the pacemaker current (If). By hyperpolarizing the cells, vagal activation increases the cells threshold for firing, which contributes to the reduction in the firing rate. Similar electrophysiological effects also occur at the AV node; however, in this tissue, these changes are manifested as a reduction in impulse conduction velocity through the AV node (negative dromotropy). In the resting state, there is a large degree of vagal tone on the heart, which is responsible for low resting heart rates. There is also some vagal innervation of the atrial muscle, and to a much lesser extent, the ventricular muscle. Vagus activation, therefore, results in modest reductions in atrial contractility (inotropy) and even smaller decreases in ventricular contractility. Muscarinic receptor antagonists bind to muscarinic receptors thereby preventing ACh from binding to and activating the receptor. By blocking the actions of ACh, muscarinic receptor antagonists very effectively block the effects of vagal nerve activity on the heart.