Blood vessel sclerosis Flashcards
Types of sclerosis
- Monckeberg’s medial calcific sclerosis
- Atherosclerosis
- Arteriosclerosis
Monckeberg’s medial calcific sclerosis
Clinically insignificant
• age > 50 years
• Involves tunica media and internal elastic lamina
• Dystrophic calcification
Stains for calcium
- Vin Kossa
2. Alizarin red stain
Arteriosclerosis
Thickening or hardening of arteries Two types: 1. Hyaline: Benign HTN, DM 2. Hyperplastic: Malignant HTN
Hyaline arteriosclerosis
- Seen in patients with benign HTN, DM
* Pink, homogenous, glassy appearance of arterial wall
Hyperplastic arteriosclerosis
- Seen in patients with malignant HTN
- Hyperplasia of wall: smooth muscle proliferation
- Concentric laminated thickening ➡️ onion skin appearance on microscopy
- Fibrinoid necrosis can also be seen (malignant HTN)
Risk factors of atherosclerosis
- Non-modifiable
- Modifiable
- Additional:
• infections: CMV, chlamydia, herpes
• lipoprotein (a, apo B-100, apo A)
• metabolic syndrome
• hyperhomocysteinemia
Non modifiable risk factors of atherosclerosis
- Age
- Male gender
- Family history
- Type A personality
Modifiable risk factors for atherosclerosis
- Sedentary lifestyle
- Obesity
- Hypertriglyceridemia
- DM/ HTN
- Smoking
Pathogenesis of atherosclerosis
- Vascular endothelial injury
- Accumulation of LDL and its oxidised form
- Monocyte adhesion
- Smooth muscle migration from tunica media to intima and proliferates
- Neo-intimal hyperplasia
- Formation of atheromatous plaque
Fatty streak
Earliest lesion of atherosclerosis
1 mm yellowish lesion
Components of a atheromatous plaque
1. Fibrous cap & shoulder: • Smooth muscle cells • Macrophages, foam cells, • Lymphocytes • Collagen, elastin, proteoglycan, neovascularisation 2. Necrotic centre: • Cell debris • Cholesterol crystals • Foam cells • Calcium
Types of plaque
1. Stable: Fibrous cap forms most of the plaque 2. Vulnerable (unstable): Necrotic court forms most of the plaque More dangerous
Complications of plaque
A. Aneurysm C. Calcification U. Ulceration T. Thrombosis E. Embolism
Vessels affected by atherosclerosis in descending order
- Abdominal aorta (M/C affected)
- Coronary artery
- Popliteal artery
- Descending thoracic aorta
- Circle of Willis (least commonly affected)
Aneurysm
Building/ dilation of a vessel wall M/C of aortic aneurysm: atherosclerosis Two types: 1. True: Involves all 3 layers of blood vessel 2. Pseudo/false: • Due to extra vascular hematoma communicating with the vessel lumen • M/C post MI rupture
Leutic aneurysm/ syphilitic aneurysm
Occurs in tertiary syphilis
Usually affects ascending aorta and vasa vasorum
Tree bark appearance like lung histoplasmosis
Mycotic aneurysm
Caused by Staphylococcus aureus
Occurs in femoral artery
