diaphragm
the muscles dividing the chest cavity from the abdominal cavity.
placenta
an organ of blood vessels that supply food and air exchange for the babies developing inside female mammals.
mammal
a warm-blooded vertebrate covered with fur or hair, breading air with lungs and a diaphragm, having a 4 chambered heart, and the largest and most developed brai
marsupial
a group of mammals in Australia which give birth to incompletely developed young, and then care for them several months in an external pouch.