What are the 2 main components of the vessel wall?
- 1. Endothelial cells (EC)
- 2. Smooth muscle cells (SMC)
What are the 2 major mechanisms of clinical disease related to blood vessels?
- 1. The bv can NARROW or become totally obstructed
- 2. The bv can WEAKEN, leading to dilation or rupture
If a change to EC is reversible and does not require new protein synthesis, like a response to histamine, what would this be classified as?
Rapid onset type of change
If and endothelial dysfunction required a change in gene expression, what would this entail?
Need to make new or altered protein synthesis and may need hours or days to occur.
What are the main things that could cause EC injury?
- 1. Cytokines and bacterial products: may lead to inflamm and/or septic shock
- 2. Hemodynamic stress and lipid products: may lead to atherosclerosis
What things is a common possible cause of thrombus formation, atherosclerosis and vascular lesions of HTN?
What cells in a vessel are responsible for vasodilation and vasoconstriction due to physiologic stimuli?
What cells in a vessel are responsible for synthesizing collagen, elastin, proteoglycans, growth factors and cytokines?
What is the SMC response to EC injury?
- They migrate to subintima where they proliferate and lay dwn ECM.
- This forms neointima and may lead to exaggerated healing and intimal thickening, with lumen narrowing or occlusion of smaller vessels
If there is a congenital anomaly such as an abnormal artery-vein connection, what is one at risk for?
- Rupture causing hemmorrhage b/c this abnormality may shunt blood from the arterial to venous side, overloading the heart.
- Of main concern for brain and GI
What is "hardening of the arteries" called?
Atertiosclerosis. This refers to the thickening and loss of elasticity in the vessel walls.
What are the 3 types of arteriosclerosis?
- 1. atherosclerosis- most important type
- 2. monckebergs medial calcific sclerosis
- 3. arterolosclerosis
Atherosclerosis can involve what arteries?
- Large ones- supplying:
- lower extremeties
What are possible consequences of atherosclerosis?
Atheromas may occlude smaller lumens, they may also rupture and induce thrombus formation
in larger vessels atheromas may weaken the vessel wall produce and aneurysm and possibly rupture
atheromas are friable and may shed emboli which can occlude vessels
- mesenteric occlusion
- sudden cardiac death
- chronic ischemic heart disease
- ischemic encephalopathy
Non-modifiable Risk factors for atherosclerosis include
age, gender, family history and genetic abnormalities
modifiable risk factors for atherosclerosis include
- hyperlipidemia (LDL are the bad ones)
- smoking and diabetes
- obesity, inactivity, stress, low estrogen post menopausal, infection
Describe the chronic inflammatory steps that respond to endothelial injury leading to atherosclerosis
Increased EC permeability- leukocytes
lipoproteins seep into vessel wall and are oxidizes, Macrophages adhere and follow
platelets, smc from media to intima, intimal thickening
Cells(smc, macrophages, WBCS); ECM; extra/intracellular lipid, new capillaries are all major components of what?