Which germ layer do you think gives rise to the human heart? Why do you think this?
The mesoderm germ layer forms in the embryos of triploblastic animals. During gastrulation , some of the cells migrating inwards contribute to the mesoderm.
This leads to the formation of a coelom. Organs formed inside the coelom move freely, grow and develop independently of the body wall. The fluid inside cushions and protects them from shocks.