Chapter 22 Disorders of Blood Flow Flashcards
What are the functions of the endothelial layer of a blood vessel?
controls transfer of molecules, controls platelet adhesion and blood clotting, modulation of blood flow and vascular resistance, metabolism of hormones…
What can happen in endothelial dysfunction?
occur in response to environmental stimuli like products that cause inflammation (cytokines, bacteria, viruses…) hemodynamic stresses (high blood pressure), lipid products (atherosclerosis)
Are endothelial dysfunctions reversible?
Potentially because the endothelial cells are frequently replaced
What do vascular smooth muscle cells do?
Vasoconstriction or vasodilation of the blood vessels
What are phospholipids?
structural components of lipoproteins, blood clotting components, myelin sheaths and cell membranes
What are the 2 types of cholesterol?
LDL
HDL
What are the types of Lipoproteins?
chylomicrons, VLDL, LDL, HDL
What are LDLs?
low density lipoproteins - main carrier of cholesterol
What is the bad cholesterol?
LDL
What roll do membrane proteins play in lipoprotein receptors?
membrane proteins bind to lipoproteins which facilitate the uptake of LDL, VDL, and chylomicrons and bring them into the cell
If more LDL or HDL is floating around in the blood what can happen?
atherosclerosis
What are the major risk factors for Atherosclerosis?
hypercholesteremia, smoking, HTN, family history of CHD, age, low HDL less than 40 mg/dL
What happens when there is less HDL in the body?
if there is less HDL that means there will be more LDL floating around which is dangerous –> HDL promotes the uptake of LDL (the bad cholesterol)
What level of cholesterol is considered hypercholesteremia?
240 mg/dL or greater
What is primary hypercholesteremia?
elevated levels of cholesterol that are independent of other health probs or lifestyle behaviors
What is secondary hypercholesteremia?
high cholesterol levels associated with other health problems or lifestyle behaviors
What are the types of lesions in atherosclerosis?
fatty streaks, fibrous atheromatous plaque, complicated lesion
What are fatty streak lesions?
thin, yellow, flat discolorations that enlarge and bind to inner lining of blood vessels where it continues to get bigger
What are atheromatous Plaque lesions?
accumulation of intracellular and extracellular lipids, proliferation of smooth muscle cells, and formation of scar tissue. Due to inflammatory responses - cells go to the area and try to eat the lipid but then the body’s response is to cover over the area
What is a complicated lesion?
contains hemorrhage, ulceration, and scar tissue deposits
What is the process of developing a plaque structure?
- endothelial cell injury
- Migration of inflammatory cells
- Lipid accumulation and smooth muscle cell proliferation
- Plaque structure
What are the major complications of atherosclerosis?
ischemic heart disease, stroke, peripheral vascular disease
What are clinical manifestations of complications of atherosclerosis?
narrowing of the blood vessel resulting in ischemia, vessel obstruction due to plaque or hemorrhage, thrombosis and formation of emboli, aneurysm formation
What is the involvement of large vessels in atherosclerosis?
thrombus formation and weakening of the vessel wall
What is the role of medium sized arteries in atherosclerosis?
ischemia and infarction due to vessel occlusion
What are the signs and symptoms of acute arterial occlusion?
limb ischemia - pain as lactic acid builds up and stimulates the nerves, paresthesia, motor weakness distal to the site of occlusion, loss of peripheral pulses, cool skin, pallor, cyanosis distal to the occlusion
What are 3 examples of arterial diseases of the extremities?
atherosclerotic occlusive disease
thromboangitis obliterans
Raynaud disease
What is atherosclerotic occlusive disease?
sudden event that interrupts arterial flow to the affected organ
What is thromboangitis obliterans?
inflammatory arterial disorder that causes thrombuses to form
What is Raynaud Disease?
intense vasospasm of the arteries and arterioles in the fingers and toes
What are the 3 types of aneurysms?
berry, fusiform and saccular, and dissecting aneurysms
What are berry aneurysms?
small berry looking spherical vessel dilation – found in the circle of Willis in brain circulation
What are fusiform and saccular aneurysms?
gradual and progressive enlargement of the aorta, found in the thoracic and abdominal aorta
What is a dissecting aneurysm?
hemorrhage into the vessel wall with longitudinal tearing (dissection) of vessel wall to form a blood filled channel - the wall tears a long thin opening and it forms a flap that fills with blood
What is venous blood circulation like?
there are one way valves in large veins, low pressure - the blood cannot move back to the heart without help so it uses the skeletal muscles to pump and push the blood back up
What are 2 types of disorders of venous circulation?
varicose veins and venous thrombosis
What are risk factors for venous stasis?
bed rest, immobility, spinal cord injury, acute myocardial infarction, congestive heart failure, venous obstruction
What are examples of venous insufficiency?
DVT, valvular incompetence, impaired nutrition
