HEART OF HUMAN

Heart is the wondrous pump that powers the human body. With each heartbeat, it sends life-giving blood throughout the body. Blood carries oxygen and food to all the body cells. The rhythmic beating of the heart begins about seven months before we are born. When the heart stops beating, we die unless a special device circulates and oxygenates our blood. The heart is a large, hollow, muscular organ divided into two pumps that lie side by side. Veins transport blood from throughout the body to the right-sided pump. That pump sends the blood to the lungs, where it picks up oxygen. The oxygenated blood then flows to the left side of the heart, which pumps it through arteries to the rest of the body.

Valves control the flow of blood through the heart. The left-sided pump, which delivers blood throughout the body, is larger and stronger than the right pump. The nervous system regulates the heart and other parts of the circulatory system. A division of the nervous system, the autonomic nervous system, automatically controls the heart rate, increasing or decreasing it, depending on the body's needs. For example, the heart pumps slowly while a person sleeps, providing relatively small amounts of oxygen to the body But the heart rate can be quickly speeded up and so increase the oxygen output enormously when a person exercises, becomes frightened, or needs to fight or run.

Disease can strike any part of the heart. Disorders of the heart and blood vessels are the leading cause of death in the United States and many other countries. The most common heart disease affects the arteries that supply the heart muscle itself with blood. Disorders of those arteries usually develop over a person's lifetime. Deposits of fatty material block the arteries and so reduce the blood supply to the heart. If the heart muscle receives too little blood, it may work poorly or even die. Damage to the heart muscle resulting from a shortage of blood is called a heart attack.


"The coagulation system is part of a tighly regulated pathway involving many enzymes," said Travis. "It has a so-called cascade pathway in the body, meaning that one enzyme turns on another, and then another and so forth. Normally these enzymes are present in an inactive form and are only activated when coagulation is required”. While the discovery is good news in potentially breaking the link between gum disease and heart disease, Travis said that P. gingivalis has a phenomenal ability to evade host defenses and even uses host enzymes for its own growth. In essence, it is telling the host to "kill me" and then evading the body's response and actually degrading host tissue.