Atherosclerosis

Overview

Atherosclerosis is a chronic disease that involves the buildup of plaque, a substance made of fat, cholesterol, calcium, and other substances found in the blood, on the inner walls of the arteries. This buildup can lead to serious problems, including heart attack, stroke, or even death. The primary components of atherosclerosis include the arterial wall, blood lipids, and immune cells.

Components of Atherosclerosis

1. Arterial Wall
   • The arterial wall is the site where atherosclerosis develops. It is composed of three layers: the intima (innermost layer), the media (middle layer), and the adventitia (outer layer). The intima is the primary site of atherosclerotic plaque formation.
2. Blood Lipids
   • Blood lipids, particularly low-density lipoprotein (LDL) cholesterol, play a crucial role in the development of atherosclerosis. High levels of LDL cholesterol in the blood can lead to the formation of atherosclerotic plaques.
3. Immune Cells
   • Immune cells, such as macrophages and T-cells, are involved in the inflammatory response that contributes to atherosclerosis. These cells can ingest LDL cholesterol and become foam cells, which are a major component of atherosclerotic plaques.

Functions of Atherosclerosis

Atherosclerosis, being a disease process, does not perform functions but rather disrupts the normal functioning of the arteries. It affects the following:

1. Blood Flow: Atherosclerosis can reduce or block the flow of blood through the arteries. This can deprive tissues and organs of the oxygen and nutrients they need to function properly.
2. Arterial Wall Integrity: The buildup of plaques can weaken the arterial wall and make it more prone to damage and rupture. If a plaque ruptures, it can lead to a blood clot that can block blood flow or break off and travel to another part of the body.
3. Inflammatory Response: Atherosclerosis is associated with an inflammatory response that can further damage the arteries and contribute to the progression of the disease.

Diseases and Disorders Associated with Atherosclerosis

Atherosclerosis can lead to a number of serious diseases and disorders, including:

1. Coronary Artery Disease (CAD): This is the most common type of heart disease and the leading cause of death in many countries. It occurs when the coronary arteries, which supply blood to the heart muscle, are narrowed or blocked by atherosclerotic plaques.
2. Stroke: A stroke can occur if an artery that supplies blood to the brain is blocked by a blood clot formed due to atherosclerosis.
3. Peripheral Artery Disease (PAD): PAD occurs when atherosclerosis narrows the peripheral arteries, often in the legs, causing symptoms such as leg pain when walking.

¹ Libby, P., Buring, J. E., Badimon, L., Hansson, G. K., Deanfield, J., Bittencourt, M. S., Tokgözoğlu, L., Lewis, E. F. (2019). Atherosclerosis. Nature Reviews Disease Primers, 5(1), 56. ↩