Cardiovascular+Problems

=**__What are the diseases of the Cardiovascular System?__**=

There are a variety of types of cardiovascular diseases, which are associated with the heart or blood vessels. The underlyling cause of such diseases is usually __atherosclerosis__, which is the accumulation of plaque (cholesterol deposits) in arteries. __Arteriosclerosis__ is the hardening of and loss of elasticity in medium or large arteries as a result of atherosclerosis. __Arteriolosclerosis__ is the hardening of and loss of elasticity in arterioles (small arteries) as a result of atherosclerosis.




 * //The Progression of Atherosclerosis//**

1. Damage to the __tunica intima__ by chemicals, viruses, physical damage, etc. 2. Blood platelets cling to the damaged site. 3. Clotting occurs on the __endothelium__ walls. 4. Injured endothelial cells release chemotatic agents which attract __monocytes__ (white blood cells), which transfrom into __macrophages__ after passing through the endothelium. 5. Chemotatic agents increase the permeability of the endothelium and allow fats and cholesterol to seep in. 6. The cholesterol and fat enter the tunica intima. 7. Macrophages, attracted to the tunica intima by the chemotatic agents, gorge on fats and swell to become __foam cells__. 8. Smooth muscle cells migrate into the area (fatty streak stage) in order to smooth out the constricting endothelium walls. The lesions created are called atherosclerosis plaques. 9. Atherosclerosis plaques of fat, macrophages, and muscle bulge into the __lumen__ (the space inside the endothelium) of the vessel. 10. Enlarging plaques hinder diffusion of nutrients from blood, as smooth muscle dies and scar tissue forms, and a __thrombus__ (a blood clot) forms.




 * //Risk Factors for Atherosclerosis//**

Uncontrollable Factors:

1. Heredity 2. Gender 3. Age

Controllable Factors:

1. Smoking 2. Hypertension (high blood pressure) 3. Blood cholesterol levels (specifically low density cholesterol) 4. Diabetes 5. Obesity 6. Lack of exercise 7. Stress


 * //Coronary Heart Disease//**

Coronary heart disease, also known as coronary artery disease, is the most common type of heart disease and is the leading cause of heart attacks. It claims more lives each year in the United States than the next 7 leading causes of death. When you have CHD, plaque accumulates in the arteries that supply the heart with blood. The plaque narrows the arteries, so the heart does not get all the blood it needs. CHD can lead to:
 * //Angina.// Angina is chest pain or discomfort that occurs when the heart does not get enough blood. It may feel like a pressing or squeezing pain, often in the chest, but sometimes in the shoulders, arms, neck, jaw, or back. It can also feel like indigestion, heartburn, weakness, sweating, nausea, cramping, and shortness of breath. Angina is not a heart attack, but having angina means you are more likely to have a heart attack.
 * //Heart attack//. A heart attack occurs when an artery is severely or completely blocked, and the heart does not get the blood and oxygen it needs for more than 20 minutes. It causes serious injury to the heart muscle, and may even result in the death of the heart muscle if blood flow is not restored within 20 to 40 minutes.