5. Explain the structure of the heart. nations of the heart​

Go through G♦♦gle that's all

The human heart is a four-chambered muscular organ, shaped and sized roughly like a man's closed fist with two-thirds of the mass to the left of midline. The heart is enclosed in a pericardial sac that is lined with the parietal layers of a serous membrane.

by going smokefree, you could improve the well-being of your friends, family, coworkers, and even your pets. here’s how the cigarettes you smoke affect the people around you.