The heart has two pumps. Each pump has two chambers, the upper and lower chambers. The upper chamber is the atrium that receives blood coming in from the veins. The lower chamber is the ventricle that forces the blood out into the arteries. There is a valve between each atrium and ventricle to prevent the blood from flowing backwards. The valves are like one-way doors that keep the blood moving in only one direction. Valves control movement of blood into the heart chambers and out to the aorta and the pulmonary artery.

All of the muscle tissues of the heart do not contract at the same time. Different parts of the heart contract at different times. When the top portion contracts, the bottom part relaxes. When the bottom contracts, the top relaxes. When a chamber contracts, it becomes smaller and the blood inside gets squeezed or pumped out.

KEY CONCEPTS

The heart is a hollow muscular organ, about the size of your fist, which is located in the center of your chest between the lungs. It is a double pump that pumps on the left and right sides. Every side is divided into two chambers, the atrium and the ventricle, each of which has a left and right portion, totaling to four chambers altogether. The top chamber is the atrium (plural: atria). The bottom chamber is called the ventricle. The valve acts as a one-way door, allowing blood to flow either forward into the next chamber, or out of the heart.

KEY CONCEPTS

Each time your heart beats, it delivers oxygen-rich blood to your body, which allows it to function properly. Your heart rate or pulse is the number of times your heart beats in a minute (BPM or beats per minute). Shorter time intervals may be used in taking the pulse as long as it comes to 60 seconds upon multiplying with a factor. When you are resting, your heart rate slows down, because your body does not need as much blood as it does when you exercise.

KEY CONCEPTS

Cigarette smoking harms nearly every organ in the body, causing many illnesses and affecting health in general. The negative effects of smoking on circulatory system include increased heart rate and blood pressure, coronary heart disease, arteriosclerosis, and vascular diseases. The respiratory diseases caused by smoking are chronic bronchitis, emphysema, asthma, cough, colds, tuberculosis, lung cancer, and other respiratory infections.

KEY CONCEPTS

The best way to prevent diseases in the respiratory and circulatory systems is to have a healthy lifestyle, which includes balanced diet, regular exercise, adequate rest, proper hygiene, and avoiding vices such as cigarette smoking and alcohol drinking. Respiratory and circulatory disease can easily be detected with regular health check-up and physical screening. Perhaps, air pollution can be discussed as well, which one's respiratory system.

KEY CONCEPTS

Several lifestyle choices can affect a person's risk for developing respiratory and circulatory diseases. Negative lifestyle weakens your system while healthy lifestyle leads to complete wellness. Vices, stressful environments, and unhealthy eating habits can cause various diseases, specifically of the respiratory and circulatory systems.