Week 7: Atherosclerosis
1. Describe the functions of the vascular endothelial cells.
Vessel layer review:
-Tunica externa (adventitia): Outmost layer of collagen and elastic fibres
-Tunica media: smooth muscle tissue
-Tunica intima: Single layer of endothelial cells which line the lumen composed of
endothelial cells and connective tissue.
-Regulates thrombosis through the elaboration of prothrombogenic molecules and
antithrombotic molecules.
-Maintains selective permeability barrier: Endothelial cells are semi-permeable and control the
transfer of small and large molecules across the vessel wall
-Regulate cell growth of smooth muscle tissues through production of growth-stimulating
factors (platelet-derived growth factor) and growth-inhibiting factors
-Regulates inflammatory and immune responses through expression of adhesion molecules
which trigger the timing of leukocyte migration and the release of inflammatory mediators.
-Maintains extracellular matrix through synthesizing collagen, laminin, and proteoglycans.
-Metabolizes lipoproteins through the oxidation of very low-density lipoproteins and
cholesterol.
2. Define the term endothelial dysfunction.
-Endothelial dysfunction refers to reversible chances in endothelial function which occur in
response to environmental stimuli. Endothelial dysfunction can cause vasoconstriction through
reducing the availability of nitric oxide, through reducing endothelial-dependent vasodilation,
or through releasing endothelins to increase vasoconstriction.
-Stimuli: cytokines, inflammatory mediators, hypertension, lipid products in
atherosclerosis, and hypoxia.
3. Describe the function of vascular smooth muscle and its role in vascular repair.
-Vascular smooth muscles located in the tunica media produce vasodilation or vasoconstriction.
, -Vasomotor nerves of the sympathetic nervous system release the neurotransmitter
norepinephrine which diffuses into the tunica media to generate impulses which contract the
muscle cell layer to produce vasoconstriction.
-Vascular smooth muscle cells synthesize collagen, elastin, and other components of
extracellular matrix, growth factors and cytokines. The migration of these materials into the
intima causes cellular proliferation. Cellular proliferation is essential to the repair of cells after
injury and is triggered by platelet derived growth factor, fibroblast growth factor, a decline in
nitric oxide, and angiotensin II.
-Excessive cellular proliferation can lead to atherosclerosis.
4. List the 5 types of lipoproteins and state their function in terms of lipid transport and
development of atherosclerosis.
Notes leading up to objective four:
Types of arteries: large elastic arteries (aorta), medium-sized arteries (coronary and renal
arteries), And small arteries and arterioles which pass through tissues.
-Large arteries: systemic transport of blood
-Medium arteries: Composed of spiralling smooth muscles, the medium arteries are
designed to distribute blood flow to organs and tissues as regulated by the relaxation and
contraction of smooth muscles.
-Small arteries: capillary blood flow
-Ischemia describes a reduction in arterial blood flow resulting in inadequate oxygen perfusion
and ultimately tissue necrosis.
-Atherosclerosis: Progressive accumulation of plaque in the large and medium arteries causing
ischemic injury.
-Risk factors: hypercholesterolemia and inflammation
-Vasculitis: inflammation of a blood vessel wall causing necrosis
-Aneurysms are the result of abnormal localized dilation of an artery due to a weakness in the
vessel wall. As an aneurysm increases in size, tension increases in the vessel wall ruptures.
Hyperlipidemia: Excess lipids in the blood
Common lipids:
1. Describe the functions of the vascular endothelial cells.
Vessel layer review:
-Tunica externa (adventitia): Outmost layer of collagen and elastic fibres
-Tunica media: smooth muscle tissue
-Tunica intima: Single layer of endothelial cells which line the lumen composed of
endothelial cells and connective tissue.
-Regulates thrombosis through the elaboration of prothrombogenic molecules and
antithrombotic molecules.
-Maintains selective permeability barrier: Endothelial cells are semi-permeable and control the
transfer of small and large molecules across the vessel wall
-Regulate cell growth of smooth muscle tissues through production of growth-stimulating
factors (platelet-derived growth factor) and growth-inhibiting factors
-Regulates inflammatory and immune responses through expression of adhesion molecules
which trigger the timing of leukocyte migration and the release of inflammatory mediators.
-Maintains extracellular matrix through synthesizing collagen, laminin, and proteoglycans.
-Metabolizes lipoproteins through the oxidation of very low-density lipoproteins and
cholesterol.
2. Define the term endothelial dysfunction.
-Endothelial dysfunction refers to reversible chances in endothelial function which occur in
response to environmental stimuli. Endothelial dysfunction can cause vasoconstriction through
reducing the availability of nitric oxide, through reducing endothelial-dependent vasodilation,
or through releasing endothelins to increase vasoconstriction.
-Stimuli: cytokines, inflammatory mediators, hypertension, lipid products in
atherosclerosis, and hypoxia.
3. Describe the function of vascular smooth muscle and its role in vascular repair.
-Vascular smooth muscles located in the tunica media produce vasodilation or vasoconstriction.
, -Vasomotor nerves of the sympathetic nervous system release the neurotransmitter
norepinephrine which diffuses into the tunica media to generate impulses which contract the
muscle cell layer to produce vasoconstriction.
-Vascular smooth muscle cells synthesize collagen, elastin, and other components of
extracellular matrix, growth factors and cytokines. The migration of these materials into the
intima causes cellular proliferation. Cellular proliferation is essential to the repair of cells after
injury and is triggered by platelet derived growth factor, fibroblast growth factor, a decline in
nitric oxide, and angiotensin II.
-Excessive cellular proliferation can lead to atherosclerosis.
4. List the 5 types of lipoproteins and state their function in terms of lipid transport and
development of atherosclerosis.
Notes leading up to objective four:
Types of arteries: large elastic arteries (aorta), medium-sized arteries (coronary and renal
arteries), And small arteries and arterioles which pass through tissues.
-Large arteries: systemic transport of blood
-Medium arteries: Composed of spiralling smooth muscles, the medium arteries are
designed to distribute blood flow to organs and tissues as regulated by the relaxation and
contraction of smooth muscles.
-Small arteries: capillary blood flow
-Ischemia describes a reduction in arterial blood flow resulting in inadequate oxygen perfusion
and ultimately tissue necrosis.
-Atherosclerosis: Progressive accumulation of plaque in the large and medium arteries causing
ischemic injury.
-Risk factors: hypercholesterolemia and inflammation
-Vasculitis: inflammation of a blood vessel wall causing necrosis
-Aneurysms are the result of abnormal localized dilation of an artery due to a weakness in the
vessel wall. As an aneurysm increases in size, tension increases in the vessel wall ruptures.
Hyperlipidemia: Excess lipids in the blood
Common lipids:
