Path Flashcards
What is a Berry Aneurysm?
Congenital cerebral aneurysms. Fatal if they rupture.
What are ateriovenous fistulas? What are 3 causes?
Direct connection of arteries and veins without a capillary system involved.
Causes: 3 I’s
- Injury (penetrating injury)
- Inflammation
- Iatrogenic (dialysis)
What is fibromuscular dysplasia?
Focal irregular thickening of the tunica intima and media layers of medium or large blood vessels. Can lead to aneurysm formation.
Most common sites and group of people where fibromuscular dysplasia occurs.
Mostly in women.
Occurs in renal, carotid, splanchnic, and vertebral arteries.
Name the 3 patterns of arteriosclerosis.
- Arteriolosclerosis
- Atherosclerosis
- Mönckeberg medial sclerosis
Name the 2 types of arteriolosclerosis.
- Hyaline
2. Hyperplastic
Describe Hyaline Arteriolosclerosis and group of people that most commonly develop it.
Narrowing of small arterioles caused by proteins leaking into the vessel wall. This results in a pink hyaline image on microscopy. Leads to ischemia of organs distal commonly seen in the glomerulus of the kidneys leading to renal failure.
Seen in diabetics w/ chronic hypertension.
Describe Hyperplastic Arteriolosclerosis and the condition it’s associated with.
Thickening of vessel wall due to smooth muscle hyperplasia. Causes an “onion skin” appearance. May lead to fibrinoid necrosis (immune complexes).
Consequence of Malignant Hypertension (hypertensive emergency that compromises an organ system)
Describe Mönckeberg medial sclerosis and the most common site it develops.
Calcium deposition in the tunica media of muscular arteries. Non-obstructing and usually found incidently.
Most commonly seen in the pelvis region.
What is atherosclerosis.
Formation of lipid plaques in the intimal layer of vessel walls. As muscle cells migrate the plaque can be said to be integrated into the media layer of the wall as it becomes surrounded by migrated muscle cells.
Major consequences: stenosis, thrombus/embolus, aneurysms
What are the two major components of an atherosclerotic plaque?
- Lipid Core
2. Fibromuscular Cap
How can a plaque lead to thrombus or embolus formation?
As the plaque grows, the fibromuscular cap becomes ischemic and can deteriorate revealing the lipid core. Platelets and clotting factors bind the core and form a thrombus. As blood pressure increases, turbulent flow can embolize the clot.
Lipid core emboli have “cholesterol clefts/slits” seen on microscopy
How can a plaque lead to an aneurysm?
The muscle cells that make up the tunica media migrate and calcify compromising blood supply. The wall become necrotic and weaken allowing out-pouching and aneurysm formation.
Most commonly in the aorta
