The Cardiovascular (Circulatory) System

The Heart and Blood Vessels (Arteries and Veins)

Jul 29, 2009 Linda Mundorff

The cardiovascular system is one of twelve organized body systems with the sole purpose of systemically transporting blood containing oxygen and other vital substances.

The heart never stops working, it beats approximately 60-80 times per minute (adult) and its purpose is to pump blood continuously throughout the body.

Heart Anatomy

The heart has four chambers, two atria and two ventricles. The atrium is a receiving chamber and functions under low pressure while the ventricle functions under high pressure to push or pump the blood.

Blood Flow

Rich oxygenated blood leaves the heart from the left side to the systemic arterial (body-wide) circulation. The arterial vessels transport life sustaining oxygen, nutrients, hormones, and immune agents throughout the body.

The veins follow the same path as the arteries with its primary role to transport deoxygenated blood and waste products to several different excretory systems for disposal. Deoxygenated blood returns to the right side of the heart via the veins and into the lungs where removal of carbon dioxide takes place.

Each cell has a layer of capillaries, which separate the arteries from the veins. It is at the capillary level where arteries deliver vital substances and veins pick-up waste products. Removal and excretion of waste products occurs in one of four sites:

• Lungs
• Kidneys
• Intestines
• Skin

Blood Pressure

According to the National Institutes of Health, about 1 in 3 adults suffer from high blood pressure. Blood pressure is a measurement used to determine how much pressure the heart is exerting within the arterial walls. Two numbers are obtained by a blood pressure reading. The first number refers to systolic pressure and it registers how much pressure the heart is exerting against the arterial wall during the heart contractions.

The second number is called diastolic and it registers how much pressure the heart exerts against the aterial wall in between beats or when at rest. A baseline blood pressure for an average sized adult is 120/80. The first number, 120 represents the systolic pressure, while the second number, 80 represents the diastolic pressure.

Blood Pressure Variations

A person's blood pressure usually varies slightly during the day with the lowest reading found upon awakening. On average, a blood pressure should only vary by a few points and it is important that everyone know their baseline blood pressure, as it is usually the observant patient who alerts the doctor to deviations.

Many things can affect blood pressure, for example:

• dehydration
• stress
• cardiovascular disease
• significant blood loss

Heart Attack

The heart has its own set of coronary arteries. When one of these major arteries is blocked oxygen is unable to flow to that part of the heart. The tissue will die resulting in a heart attack or myocardial infarction. During a heart attack the heart is still beating, however a cardiac arrest will result if medical intervention is not swift.

Cardiac Arrest

When the heart fails to receive its own supply of oxygen tissue will die and the heart will stop beating. The heart simply quivers and not only is blood failing to supply the heart it is also not being transported throughout the body.

Therefore, to circumvent the possibility of brain damage, medical intervention or defibrillation must occur within 3-5 minutes of the incident. Because medical intervention does not normally occur within the parameters mentioned survival from a cardiac arrest is usually less than 5%.

Cardiovascular Disease

Many conditions can affect the abilities of the heart and blood vessels. Below is a very short list of possible problems:

• hardening of the arteries due to decrease in vessel elasticity(arteriosclerosis)
• hardening of the arteries due to plaque buildup within the arteries (atherosclerosis)
• blood clot (thrombus)
• weakened arterial wall (aneurysms)
• high blood pressure (hypertension)
• high cholesterol (hyperlipidemia)

There are a number of risk factors associated with cardiovascular disease, such as sedentary lifestyle, diet, and cigarette smoking. An active lifestyle consisting of aerobic exercises at least 3 times a week, low-fat and low-salt diet, and cessation of cigarette smoking can decrease one's chance of developing cardiovascular disease significantly.

In conclusion, the cardiovascular system is responsible for ensuring that all vital nutrients and other substances necessary for all body systems to function properly. This system has the number one spot for illnesses and death in the United States. Implementing a heart smart lifestyle of exercise, stress reduction, and proper nutrition for example will decrease the likelihood of developing cardiovascular problems later in life.

The copyright of the article The Cardiovascular (Circulatory) System in General Medicine is owned by Linda Mundorff. Permission to republish The Cardiovascular (Circulatory) System in print or online must be granted by the author in writing.

organs of the cardiovascular system

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