Final answer:
An anatomy student focusing on the structural changes of the heart during embryonic development studies developmental biology, encompassing embryonic growth, cardiac anatomy, and the formation of the human circulatory system.
Step-by-step explanation:
An anatomy student studying how the heart structure changes during the first two months after fertilization is conducting a study in the field of developmental biology, specifically focusing on embryonic development and cardiology. The heart forms from a tissue called mesoderm around 18 to 19 days after fertilization and is the first functional organ to develop. By day 21 or 22 post-fertilization, the heart begins beating, marking a critical phase in embryonic growth as it starts distributing blood and facilitating the vital exchange of nutrients, oxygen, and wastes between the developing baby and the mother.
During the embryonic stage, which spans from weeks 3 to 8, the embryo's simple tube-like heart starts undergoing structural changes, developing the four heart chambers. Around week 4, the heart is capable of electrical conduction and contraction, and by the end of this stage, organized circulation patterns are established, crucial for the survival of the developing human. Knowing these details can enable understanding of the heart's role in developmental anatomy and how any abnormalities during this critical stage might lead to congenital heart defects.