Faculty of allied medical sciences

Faculty of allied medical Faculty of allied medical sciencessciences

Histopathology and cytologyHistopathology and cytology

((MLHC-201MLHC-201))

DISEASES OF DISEASES OF BLOOD VESSELSBLOOD VESSELS

SupervisionSupervision::

Prof.Dr. Noha RagabProf.Dr. Noha Ragab

OutcomesOutcomes

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

ARTERIOSCLEROSISARTERIOSCLEROSIS

Definition:Definition:

This is thickening and hardening of This is thickening and hardening of arterial walls. Arteriosclerosis arterial walls. Arteriosclerosis includes:includes:

AtherosclerosisAtherosclerosis Mockenberg's sclerosis (medial Mockenberg's sclerosis (medial

calcification)calcification) arteriolosclerosis arteriolosclerosis

ATHEROSCLEROSIS ATHEROSCLEROSIS (ATHEROMA)(ATHEROMA)

Definition:Definition:

Atherosclerosis; this is patchy Atherosclerosis; this is patchy thickening of the intima of arteries by thickening of the intima of arteries by lesions composed of deposited lipids lesions composed of deposited lipids surrounded by proliferating surrounded by proliferating connective tissue. connective tissue.

Each of these lesions is called atheromaEach of these lesions is called atheroma

Risk factors:Risk factors:

High levels of plasma lipids High levels of plasma lipids (hypercholesteriamia) cause (hypercholesteriamia) cause endothelial damageendothelial damage

Hypertension : is a major risk factorHypertension : is a major risk factor Smoking : causes endothelial damageSmoking : causes endothelial damage Diabetes mellitusDiabetes mellitus Life style: lack of exercise, stress, Life style: lack of exercise, stress,

obesityobesity Familial hereditary factors Familial hereditary factors

Pathological featuresPathological features

Sites of atherosclerosis:Sites of atherosclerosis: Large arteries: aorta and its main Large arteries: aorta and its main

branchesbranches Small arteries : coronaries, cerebral Small arteries : coronaries, cerebral

and renal arteriesand renal arteries Medium sized arteries as femoral arteryMedium sized arteries as femoral artery

PathogenesisPathogenesis::

The pathogenesis of disease is The pathogenesis of disease is according to two theoriesaccording to two theories

Chronic Endothelial Damage TheoryChronic Endothelial Damage Theory Thrombogenic TheoryThrombogenic Theory

Chronic endothelial Chronic endothelial damagedamage

Caused by:Caused by: Vascular stress (hypertension)Vascular stress (hypertension) Toxic products of cigaretteToxic products of cigarette

Endothelial injury Endothelial injury allows trapping of LDL allows trapping of LDL (cholesterol) in the sub-endothelial part of (cholesterol) in the sub-endothelial part of the intimathe intima

Also endothelial injury Also endothelial injury enhance the enhance the adherence of platelets adherence of platelets release of platelet release of platelet factors factors stimulation of proliferation of stimulation of proliferation of connective tissue & smooth musclesconnective tissue & smooth muscles

Thrombogenic theoryThrombogenic theory::

Fibrosis of an arterial thrombus can Fibrosis of an arterial thrombus can give rise to atheromatous plaque give rise to atheromatous plaque (lipids within the blood involve the (lipids within the blood involve the thrombus)thrombus)

Atheroma of AortaAtheroma of Aorta

Effects and Effects and ComplicationsComplications::

(A) Ischemic effects:(A) Ischemic effects: Ischemia may be incomplete i.e. narrowing or complete i.e. Ischemia may be incomplete i.e. narrowing or complete i.e.

occlusion occlusion

Small arteriesSmall arteries Coronaries: Coronaries:

Narrowing Narrowing arteriosclerosis heart diseases arteriosclerosis heart diseases Occlusion Occlusion myocardial infarction myocardial infarction

Femoral artery:Femoral artery: Narrowing Narrowing intermittent claudication intermittent claudication Occlusion Occlusion dry gangrene of leg dry gangrene of leg Large arteries:Large arteries: Aorta Aorta Thrombosis may develop over atheromata and this may be Thrombosis may develop over atheromata and this may be

detached to form thrombo-emboli which can cause systemic detached to form thrombo-emboli which can cause systemic embolism leading to infarctions in different organsembolism leading to infarctions in different organs

Angiogram - Embolism Angiogram - Embolism

InfarctionInfarction

Narrowing of coronaries by atheroma

Occlusion of coronaries by atheroma

(B) Aneurysms formation:(B) Aneurysms formation: A local enlargement of an arteryA local enlargement of an artery They are due to stretch of the atrophic They are due to stretch of the atrophic

mediamedia The most common are:The most common are:

The cerebral arteriesThe cerebral arteries The aorta The aorta

HYPERTENSIONHYPERTENSION

HYPERTENSIONHYPERTENSION

Definition:Definition: Hypertension is persistent elevation Hypertension is persistent elevation

of blood pressure above normal. The of blood pressure above normal. The normal adult pressure is 140/90normal adult pressure is 140/90

Types of hypertension:Types of hypertension: Primary (essential) hypertension: Primary (essential) hypertension:

(90%)(90%) Secondary hypertension: (10%)Secondary hypertension: (10%)

Questions

1) Define Atherosclerosis and Hypertension ?

2) What is the risk factor for developing atherosclerosis ?

3) Explain with drawing the aneurysms formation ?