A new study shows that the heart of human embryos actually starts pumping on day 16 of its conception.

During a person’s lifetime, his heart will pump for a total of three billion times, however, there is no confirmation when the really pumping begins. Earlier studies reveal that it occurs 21 days from conception but a more recent study says it starts at day 16.

Researchers from the University of Oxford, England experimented on mouse hearts which according to biologists have a closer resemblance to human hearts. Human embryos were not used because capturing the image and activation of its heart is hard to achieve.

Based on current research, a mouse’s heart starts beating on the eighth day from conception. At this phase, the mouse’s heart now in the shape of a tiny tube pumps oxygen and helps provide nourishment to its entire system.

A more in-depth study of mouse heart at its developmental stage came out with a lower figure of 7.5 days. Taking into account the biological structure of its heart at this phase of its life and equating it to those of human embryos, it may be concluded that the human heart starts beating at day 16.
The team explains that at this phase, the “cardiac crescent” in mice and humans (and some mammals) start to develop.
According to University Professor Paul Riley, identifying the first heart beat in human embryos and looking deep into probable issues affecting heart development would aid in arresting heart complications on embryos while it is still developing.

Professor Riley’s team monitored molecular calcium present in the mouse embryos. Calcium in an ionized state is likened to a messenger, sending electrical signals from one neuron to another during fertilization.

It has been established that calcium ions play a huge role in jump-starting cardiomyocytes in heart muscles to begin pumping.

Based on this info, the team marked calcium molecules with a fluorescent material and successfully monitored the point at which the molecules trigger cardiomyocytes to activate.

This new revelation that the human hearts begin pumping on day 16 is vital to the prevention of heart problems arising at the developmental stage of human embryos. Moreover, it will also help physicians to better understand and repair damaged adult hearts due to strokes and serious illnesses.