1. Faculty of allied medical sciences
Histopathology and cytology
(MLHC-201)

2. DISEASES OF BLOOD VESSELS
Supervision:
Prof.Dr. Noha Ragab

3. Outcomes
By the end of this lecture the student will understand the Atherosclerosis , causes and complication .

4. ARTERIOSCLEROSIS Definition:
This is thickening and hardening of arterial walls. Arteriosclerosis includes:
Atherosclerosis
Mockenberg's sclerosis (medial calcification)
arteriolosclerosis

5. ATHEROSCLEROSIS (ATHEROMA)
Definition:
Atherosclerosis; this is patchy thickening of the intima of arteries by lesions composed of deposited lipids surrounded by proliferating connective tissue.
Each of these lesions is called atheroma

6. Risk factors:
High levels of plasma lipids (hypercholesteriamia) cause endothelial damage
Hypertension : is a major risk factor
Smoking : causes endothelial damage
Diabetes mellitus
Life style: lack of exercise, stress, obesity
Familial hereditary factors

7. Pathological features
Sites of atherosclerosis:
Large arteries: aorta and its main branches
Small arteries : coronaries, cerebral and renal arteries
Medium sized arteries as femoral artery

8. Pathogenesis: The pathogenesis of disease is according to two theories
Chronic Endothelial Damage Theory
Thrombogenic Theory

9. Chronic endothelial damage
Caused by:
Vascular stress (hypertension)
Toxic products of cigarette
Endothelial injury  allows trapping of LDL (cholesterol) in the sub-endothelial part of the intima
Also endothelial injury  enhance the adherence of platelets  release of platelet factors  stimulation of proliferation of connective tissue & smooth muscles

10. Thrombogenic theory:
Fibrosis of an arterial thrombus can give rise to atheromatous plaque (lipids within the blood involve the thrombus)

11. Atheroma of Aorta

12. Effects and Complications:
(A) Ischemic effects:
Ischemia may be incomplete i.e. narrowing or complete i.e. occlusion
Small arteries
Coronaries:
Narrowing  arteriosclerosis heart diseases
Occlusion  myocardial infarction
Femoral artery:
Narrowing  intermittent claudication
Occlusion  dry gangrene of leg
Large arteries: Aorta
Thrombosis may develop over atheromata and this may be detached to form thrombo-emboli which can cause systemic embolism leading to infarctions in different organs

13. Angiogram - Embolism Infarction

14. Narrowing of coronaries by atheroma

15. Occlusion of coronaries by atheroma

16. (B) Aneurysms formation: A local enlargement of an artery
They are due to stretch of the atrophic media
The most common are:
The cerebral arteries
The aorta

17. HYPERTENSION

18. HYPERTENSION Definition:
Hypertension is persistent elevation of blood pressure above normal. The normal adult pressure is 140/90

19. Types of hypertension:
Primary (essential) hypertension: (90%)
Secondary hypertension: (10%)

22. Questions
Define Atherosclerosis and Hypertension ?
What is the risk factor for developing atherosclerosis ?
Explain with drawing the aneurysms formation ?