Atherosclerosis and atheroma

Author(s): and

Learning outcomes Part 1 of 13

  • Definitions – atherosclerosis, atheroma
  • Describe the pathogenesis of atherosclerosis
  • Describe the morphology of atheroma development
  • Describe the consequence of atherosclerosis on other body systems

Definitions Part 2 of 13

  • Atheroma – a reversible accumulation of degenerative tissue in the intima of the arterial wall
  • Atherosclerosis – hardening of any artery due to an atheromatous plaque
  • Arteriosclerosis – hardening (and loss of elasticity) of small to medium arterioles

Pathogenesis of atherosclerosis Part 3 of 13

1. Chronic endothelial insult leads to expression of growth factors

2. Lipid is deposited in the intima and macrophages digest this, forming foam cells

3. Smooth muscle infiltrates & proliferates, connective tissue forms a thin fibrous cap on the surface

©Manosinistra [Public domain], from Wikimedia Commons
Accumulation of lipid and foam cells with inflammation and smooth muscle infiltration in early atheromatous plaques. Adapted from: https://commons.wikimedia.org/wiki/File:Atherome_step3_fr.svg

Progression of an atheromatous plaque Part 4 of 13

Complications of atheromatous plaques Part 5 of 13

Quiz - macroscopic appearance of atheroma Part 6 of 13

 

 

Microscopic appearance of atheroma - normal histology Part 7 of 13

Microscopic appearance of atheroma 2 Part 8 of 13

This is another cross-section of an artery. The intima is labelled A and the media is labelled B.

©Patho [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons
Adpated from: https://commons.wikimedia.org/wiki/File:Atherosclerosis,_HE_4.JPG

Macroscopic appearance of atheroma 3 - complicated atheroma Part 9 of 13

Microscopic appearance of atheroma 4 - fibrolipid plaque Part 10 of 13

Distribution (and consequences) of atherosclerosis Part 11 of 13

Atheroma and atherosclerosis are usually found near anastomoses of large arteries – bifurcation of common carotids, Circle of Willis and bifurcation of common iliac arteries etc.

 

Consequences of atheroma Part 12 of 13

Summary Part 13 of 13

Atheroma is a very important process in medicine and is a contributor to a large burden of disease worldwide.

 

By the end of this module you should be able to:

  • Discuss the aetiology and pathophysiology of atherosclerosis
  • Discuss the sites it most commonly affects and the consequences that can happen at these sites