PATHO LECTURE 5 (chapter 26 and chapter 28) EXAM 2

what does the vascular endothelium of blood vessels do

regulates thrombosis, controls transfer of molecules, modulates blood flow

how do vascular endothelium regulate thrombosis

von willebrand factor for platelet adhesion and plasminogen activator which does fibronlysis

how does vascular endothelium modulate blood flow

nitric oxide vasodilator

how does vascular smooth muscle constriction work

SNS stimulation releases norepinephrine alpha 1 receptor to cause vasocontriction

is there relaxation in local regulation of vascular smooth muscle

no

what is systolic blood pressure

120 mmHg-- contracting phase of heart

when does systolic pressure happen

when blood is ejected from ventricles (high)

what is diastolic pressure

80 mmHg--relaxation phase of heart

when does diastolic pressure occur

when the ventricles relax (lower)

blood pressure is altered by what

cardiac output, blood volume, and peripheral resistance to blood flow

when the vessels constrict, what is BP like

high PR so high BP

when vessels dilate, what is BP like

low PR so low BP

in the sympathetic branch of ANS, what does increased output lead to

vasoconstriction and increased BP

in the sympathetic branch of ANS, what does decreased output lead to

vasodilation and decreased BP

what happens to peripheral resistance in the sympathetic branch of ANS

it increases

BP is directly proportional to what

blood volume

what is cardiac output

blood volume pumped in 1 minute

how does antidiuretic hormone affect BP

increases it

how does aldosterone affect BP and blood volume

both increase

how does renin-angiotensin-aldosterone affect the blood vessel and BP

vasoconstriction occurs and BP increases

what happens in short term (acute) regulation of blood pressure

neural mechanism baroreceptors respond moment by moment

managed by SNS

what are baroreceptors sensitive to

pressure changes

hormonal mechanisms of blood pressure regulation include what and do what

renin-angiotensin-aldosterone, epinephrine

acutely regulate BP and alter vascular tone

long term regulation of blood pressure works within what time frame

within hours or days

what organ has a role in regulating ECF (blood) volume during long term blood pressure regulation

kidney

what are the effects of ADH in blood pressure regulation

increasing BP and volume

what are the affects of ANP on blood pressure regulation

decreases blood volume and blood pressure

increased blood volume leads to what blood pressure and decreased blood volume leads to what blood pressure

high; low

what are the classifications of lipoproteins

chylomicrons

very low desnity lipoprotein (VLDL)

low density lipoprotein (LDL)

high density lipoprotein (HDL)

what does very low density lipoprotein do

carries large amounts of triglycerides

what is the role of low density lipoprotein

main carrier of cholesterol

high density lipoprotein is what percent protein

50%

lipids are transported in combination with what

proteins

what lipoprotein is 80-90% triglycerides and 2% protein

chylomicrons

what lipoprotein is 55-65% triglycerides, 10% cholesterol, and 5-10% protein

VLDLs

what lipoprotein is 10% triglycerides, 50% cholesterol, and 25% protein

LDLs

what lipoprotein is 5% triglycerides, 20% cholesterol, and 50% protein

HDLs

what does low density lipoprotein do with respect to lipid transport

transports cholesterol from liver to cells

major factor contributing to atheroma formation

what does high density lipoprotein do with regards to lipid transport

transports cholesterol away from the peripheral cells to liver--"good" lipoprotein

catabolism in liver and excretion

what are the steps of lipoprotein transport

dietary intake of cholesterol and triglycerides

Chylomicrons absorbed into blood and lymph

lipid uptake by adipose and skeletal muscle cells

remnants to liver

liver synthesizes lipoproteins

LDL transports cholesterol to cells

LDL attaches to LDL receptor in smooth muscle and endothelial tissue

HDL transports cholesterol from cells to liver

what are the serum cholesterol levels in hypercholesterolemia

240 mg/dL or greater

what do serum cholesterol levels above 240 mg/dL contribute to

heart attack, stroke, or other cardiovascular event associated with atherosclerosis

what does atheroma cause

narrowing or complete blockage of blood vessels

primary hypercholesterolemia describes what

elevated cholesterol levels that develop independent of other health problems or lifestyle behaviors (genetic basis)

secondary hypercholesterolemia is associated with what

other health problems and behaviors (DM, obesity)

is HDL or LDL considered good cholesterol

HDL

what is arteriosclerosis

general term for all types of arterial changes

what happens in arteriosclerosis

degenartive changes in small arteries and arterioles

loss of elasticity

lumen gradually narrows and may become obstructed

cause of increased BP

what is artherosclerosis characterized by

presence of atheromas in large arteries

what do plaques consist of in atherosclerosis

lipids, calcium, and possible clots

how does atherosclerosis develop

damage to endothelial wall initiates the process (HTN? Bacteria?) and leads to inflammation

cholesterol accumulates in damaged area and is oxidized free radical formation

endothelial cells release kinins, inflammatory chemicals

macrophages respond and phagocytize cholesterol become foam cells plaque smooth muscle divides and grows over the fatty core

what are the characteristics of stable plaque

have thick fibrous caps

partially block vessels

do not tend to form clots or emboli

what are the characteristics of unstable plaque

have thin fibrous caps

plaque can rupture and casue a clot to form

may completely block the artery or become an embolus

what are the nonmodifiable risk factors for artherosclerosis

age, gender, and genetic or familial factors

what are the modfiable risk factors for atherosclerosis

obesity, sedentary lifestyle, cigarette smoking, diabetes mellitus, poorly controlled hypertension, combination of oral contraceptives and smoking

what is the progression of atherosclerosis

response to injury, fibrous plaque, fatty steak, complicated lesion

what are the types of lesions assoicated with atherosclerosis

fatty streaks, fibrous atheromatous plaque, and complicated lesion

what are fatty streaks

thin, flat yellow intimal discolorations that progressively enlarge

what is a fibrous atheromatous plaque

the accumulation of intracellular and extracellular lipids, proliferation of vascular smooth muscle cells, and formation of scar tissue

what is a complicated lesion

contains hemorrhage, ulceration, and scar tissue deposits

in large vessels, the important complications are those of what in artherosclerosis

thrombus formation and weakening of the vessel wall

in medium sized arteries, what is more common in atherosclerosis

ischemia and infarction due to vessel occlusion are more common

arteries supplying what are more frequently involved during artherosclerosis

heart, brain, kidneys, lower extremities, and small intestine

what are the diagnostic tests for artherosclerosis

serum lipid levels (LDL, HDL)

exercise stress testing (screening for arterial obstructior)

nuclear medicine studies (determine the degree of tissue perfusion)

what are the consequence of atherosclerosis for the heart

angina pectoris or myocardial infarction in case of total occlusion

what are the consequence of atherosclerosis for the brain

transient ischemic attack and cerebrovascular accident in case of total occlusion

what are the consequence of atherosclerosis for the peripheral arteries

aneurysm in aorta (rupture and hemmorhage)

peripheral vascular disease-gangrene and amputation in iliac arteries

what is management for atherosclerosis

weight loss, increase exercise, dietary modification, reduction of sodium intake, control hypertension, control primary disorder, cessation of smoking, antilipidemic drugs, surgical intervention (coronary artery bypass grafting)

acute arterial occlusion results from what

thrombus or embolus

peripheral signs of acute arterial occlusion are what

pistol shot (Acute)

pulselessness

paralysis

paraesthesia

pain

pallor

polar (cold)

how can blood flow be restored in acute arterial occlusion

thrombectomy, thrombolytic, anticoagulant, embolectomy

what happens in peripheral arterial disease

occlusion of vessels of lower extremities

how many americans have peripheral arterial disease

8-12 million over 65

what increases risk greatly for peripheral arterial disease

DM-diabetes mellitus

onset of symptoms in peripheral arterial disease

asymptomatic initially (anastomosis-connections between blood vessels)

50% narrowing occurs before symptoms felt

when does peripheral arterial disease manifest

acutely when thrombi, emboli, or acute trauma compromises perfusion (rare)

what are the peripheral arterial disease signs

intermittent claudication

thinning of skin

may feel cold with weak distal pulse

what is intermittent claudication

pain with walking, relieved with rest

gastrocnemius requires large amount of O2

why does thinning of skin occur in peripheral arterial disease and what happens with it

less O2 delivered

skin appears shiny, hair loss, nail changes

what happens in a dependent position in peripheral arterial disease and why

redness due to gravity

what is the treatment of peripheral arterial disease

walking slowly

avoid injury

antiplatelet agents

bypass grafting

angioplasty

thromboangitis obliterans buerger disease affects what

plantar and digital vessels in foot

what is the cause of thromboangitis obliterans buerger disease and is it atherosclerotic

cause is unknown and NON atherosclerotic

what is thromboangitis obliterans buerger disease

acute inflammatory problem leading to clots

what happens in thromboangitis obliterans buerger disease

pain at rest

ischemia ulcerations (gangrene and amputations)

who does thromboangitis obliterans Buerger disease primarily affect

men over 40, heavy smokers

what happens in raynaud disease and phenomenon

intense basospasm of arteries, arterioles in fingers or toes

excessive vasoconstriction then followed with hyperemia and throbbing then back to normal

what is raynaud disease and phenomenon precipitated by

exposure to cold or strong emotions (SNS)

who does raynaud disease and phenomenon affect

healthy young women

raynaud disease and phenomenon is associated with what

frostbite and collagen disease

vasodilators are the treatment for what diseases

thomboangitis obiterans buerger disease and raynaud disease phenomenon

what is an aneurysm and how does it develop

localized dilation and weakening of arterial wall

develops from a defect in the medial layer

what are the shapes of aneurysms

saccular

fusiform

dissecting aneurysm

what is a saccular aneurysm

bulging wall on the side

what is a fusiform aneurysm

circumferential dilation along a section of artery

what is a direct aneurysm

develops when there is a tear in the intima of the wall and blood continues to dissect or separate tissues

where is a berry aneurysm most commonly found and what does it consist of

most often found in the circle of Willis in the brain circulation

consists of a small, spherical vessel dilation

fusiform and saccular aneurysms are most commonly found where and characterized by what

most often found in the throacic and abdominal aorta

characterized by gradual and progressive enlargement of the aorta

what risks are associated with aneurysms

wall of artery weakens and stretches so risk of rupture and hemorrhage and risk of clot formation

what are the causes of aneurysms

artherosclerosis

degenration of smooth muscle

genetic defects

trauma

infections