Flashcards in Pathology of Hypertension Deck (33)
What can hypertension lead to?
-atherosclerotic CV disease
What are the systolic and diastolic cutoffs for increased risk of ACD?
140 mm Hg and
90 mm Hg
lower with someone with diabetes and AA patients
What causes hypertension?
-idiopathic (essential HTN) 90+%
- secondary causes such as renal disease, renal artery narrowing, adrenal disorders
What are some rare single gene disorders that can lead to HTN?
-Aldosterone metabolism- leads to increased aldosterone, increased salt and water, and plasma expansion
- Sodium resorption
Why would renal artery narrowing lead to HTN?
When the kidney thinks that there isn't enough blood in the body (because it's not getting any) it will increase BP
What is the equation for cardiac output?
CO= HR (heart rate) x SV (stroke volume)
Endothelial injury leads to what?
- smooth muscle growth
- matrix synthesis
both lead to lumenal decrease
What is arteriosclerosis?
hardening of the arteries
What happens in atherosclerosis?
LDL lipoproteins enter the intima following endothelial injury and they are taken up by macrophages leading to foam cells. Eventually the proteins and macrophages die, leaving a necrotic lipid dense core plaque with a fibrous cap over the top
atherosclerosis= lipid deposit
What happens if the fibrous cap gets too thin?
the plaque can rupture and thrombi can form
What is medical calcific sclerosis (Monckenbergs)?
incidental calcification in the media
What is Arteriolosclerosis?
thickened walls in arterioles that is associated with hypertension and diabetes
What are the types of arteriolosclerosis?
hyaline arteriolosclerosis and hyperplastic arteriolosclerosis
What is hyaline arteriolosclerosis caused by?
increased pressure due to hypertension pushes the plasma proteins into vessel walls leading to increased ECM construction and the intima expands
What is hyaline arteriolosclerosis associated with?
What can hyaline arteriolosclerosis lead to?
nephrosclerosis- eventually the kidney doesn't have the proteins needed to function
What is hyperplastic arteriolosclerosis associated with?
more severe hypertension (systolic over 200 mm Hg) that leads to an onion skinning appearance of the vessel caused by smooth muscle proliferation
Very high HTN can lead to fibrinoid deposits and vessel wall necrosis
NOT much inflammation here (distinguish from vasculitis)
What is a complicated lesion?
when the fibrous cap of a plaque wears down, the lipid dense core can form a thrombus/embolus
What causes aneurysm?
eventually the plaque will weaken the intima and media
What are the constitutional risks of plaque formation?
- age (silent until 40-60)
- gender- premenopausal women protective effect (estrogen?- possible)
What are the acquried risks of plaque formation?
-inflammation (increased CRP)
- Chronic endothelial injury
- Accumulation of lipoproteins that diapedes into the intima
- Inflammatory response of monocytes come into the intima and eat the LDL to try to remove it
- Cytokines promote smooth muscle growth
- Macrophages eventually die leaving necrotic center
- Fibrous cap forms over lipid dense core
- Continued growth and remodeling
What is an unstable plaque?
Occurs when 70-80% of lumen (critical stenosis) is obstructed and become more clinically evident and prone to rupture and embolus OR aneurysm
What are common vessels affected by atherosclerosis?
- **infrarenal abdominal aorta** (very turbulent)
- Coronary arteries
- Popliteal arteries
- Internal carotid arteries
- Circle of willis
Where is the vaso vasorum common?
aortic arch since it is so thick so it provides blood to the media and adventitia
What causes thrombus formation following plaque formation?
breaking open of the fibrous cap causes hemorrhage which clots and forms a thrombus
T or F. True aneurysms involve all three layers of the vessel wall
What is a dissection?
a tare in the intima due to problems with the media (usually vaso vasorum is messed up and cant get blood to the media) and its integrity is compromised or someone with collagen issues- ehlers dances, etc.)
What causes aneurysm?
atherolsclerosis is a disease of the intima, however, in advance disease, the plaque compresses and thins the media, weakening the wall, causing a loss of elasticity leading to aneurysm