Blood Vessels

Question 1

Name the most common sites of atherosclerosis.

Answer 1

ALCPIC

Lower abdominal aorta 
Iliac arteries
Coronary artery 
Popliteal artery 
Internal carotid artery 
Circle of Willis

Question 2

What are the complications of atherosclerosis?

Answer 2

1. Rupture, erosion, ulceration - Exposes Thrombogenic contents to the blood, thrombosis and occlusion
2. Intraplaque hemorrhage - expansion and occlusion of lumen
3. Atheroembolism- After plaque rupture, debris from the contents discharged into circulation as microemboli
4. Aneurysm- pressure from plaque weakens tunica media and disrupts elastic lamina

Question 3

What is aneurysm. Types and patterns. Pathogenesis.

Answer 3

Localised abnormal dilation of a blood vessel or the heart, which may be acquired or congenital.

Types:

1) True aneurysm: All 3 wall layers involved eg. MI, Atherosclerosis
2) False aneurysm: Occurs when extra vascular hematoma communicates with intravascular space eg. Post MI- ventricular wall rupture contained by adhesions.

Patterns:

1) Saccular: Spherical outpouching eg. Berry aneurysm
2) Fusiform: Cylindrical/Circumferential dilation of a segment of an artery

Pathogenesis:

1) Intrinsic weakness of vessel wall eg EDS (type 3 collagen defect)
2) Abnormal TGF-beta signalling (excessive) eg. Marfan synd, Loeys Dietz syndrome
3) Imbalance b/w collagen synthesis and degradation: Due to inflammation eg. Atherosclerosis, vasculitis
4) Acquired weakening of vessel wall eg. Syphilis, hypertension etc

Question 4

Define atherosclerosis.

Answer 4

It is a progressive disease of intima

• involving large and medium-sized
• elastic and muscular arteries
• characterized by focal lipid- rich intimal lesions called atheromas

Question 5

Onion skins in pathology.

Answer 5

1. Malignant HTN: malignant hypertension leads to hyperplastic arteriosclerosis. Onionskin appearance on H&E
2. Chronic inflammatory demyelination g poly neuropathy- nerve biopsy (ONION BULB)
3. Spleen in SLE
4. EM in Tay Sach disease
5. X Ray in Ewing Sarcoma
6. Primary sclerosing cholangitis: Biposy

Question 6

What are ANCAs?

Answer 6

Anti-Neutrophil Cytoplasmic Antibodies.
Antibodies against the granules of neutrophils.

1. C-anca (PR3-ANCA) :
   - Directed against Azurophilic granules.
   - Seen in Wegner Granulomatosis (GPA)
2. P-Anca (MPO-ANCA)
   - Directed against lysosomal granules
   - Seen in Churg Strauss and Microscopic Polyangitis

Other conditions where ANCA found:
SLE, IBD