Natsu with Lisanna, watching over their Dragon Egg. One day, Natsu found an egg in the forest east of Magnolia. Thinking it to be a Dragon Egg, Natsu took it to the guild and asked Makarov to make it hatch, but Makarov and Erza told him that he was the only one that could make the egg hatch; through love and care.
1 As a Decompression Chamberâ This is a hyperbaric chamber used by surface-supplied divers (commercial divers mostly) to make their decompression stops.  As Recompression chamberâ A hyperbaric chamber is used to treat or prevent patients suffering from decompression sickness.
Chambers of the Heart. The heart is composed of four well separated chambers. The two superior chambers are the atria (= entry halls) , and the two inferior chambers are the ventricles (= little bellies). The atria are the receiving chambers, they receive venous blood from systemic and pulmonary circulation and pump it down into the ventricles. The ventricles are the distributing chambers, they pump blood out of the heart into the peripheral circulation.