disorders of blood flow

endothelial cells

innermost lining of arteries and veins

control transfer of :

• molecules across vascular wall

• platelet adhesion

• blood clotting

• blood flow

• vascular resistance

• hormone metabolism

• immune/inflammatory regulation

• growth of other cells

endothelial dysfunction

damage to the inner lining of vessels with potentially reversible chagnes if the basement membrane remains intact

features of endothelial dysfunction

features:

• increased permeability

• inappropriate filtration

• inflammation

• cell swelling

• thickening

• gap formation

causes of endothelial dysfunction

cytokines

bacteria

viruses

hemodynamic stress

lipid products

cholesterol buildup

hypoxemia → hypoxia

necrosis

dehydration

high blood pressure

vascular smooth muscle

cells that control vasoconstriction and vasodilation

regulated by ANS, sympathetic and nitric oxide

involved in ECM production

healing

pathological processes

triglycerides

lipid used in energy metabolism

phospholipid

lipid that make up lipoprotein

blood clotting components

myelin sheath

cell membrane

cholesterol

lipid with chemical activity similar to other lipids; contribute to cell structure and pathology

hyperlipidemia

elevated levels of lipid in the blood

chylomicrons

lipoprotein that transport dietary lipids

VLDL = very-low density lipoprotein

lipoproteins that transport triglycerides from the liver

IDL = intermediate density lipoprotein

formed from VLDL breakdown

LDL = low density lipoprotein

main carrier of cholesterol

"bad” cholesterol that deposit in vessel walls

HDL = high-density lipoproteins

“good” cholesterol; removes lipids from tissues and transports them to the liver

Lipid Panel

blood test measuring circulating fats

total cholesterol: ideal < 130mg/dL

HDL-C: ideal > 0.4

LDL-C: < 2.5

triglycerides: ideal < 2

lipoprotein receptors

membrane protein that allow uptake of LDL, VLDL, chylomicrons and IDL into cells

lipoprotein receptor defect

genetic abnormality causing elevated lipid levels independent of diet

Hypercholesterolemia

genetic or lifestyle conditions with elevated cholesterol and triglycerides in blood

primary hypercholesterolemia

genetic; due to defective receptors

secondary hypercholesterolemia

caused by lifestyle or other health conditions

effects of hypercholesterolemia

fat buildup

cholesterol ≥ 240 mg/dL

increased risk of heart attack

stroke

atherosclerosis

arteriosclerosis

thickening and hardening of aterial walls with decreased elasticity

athersclerosis

specific type of arteriosclerosis caused by plaque buildup of lipids, cholesterol and triglycerides

ASVD = arteriosclerotic vascular disease

involves inflammation and calcified plaque formation

Mockeberg’s arteriosclerosis

calcification of tunica media with destruction of muscle and elastic fibers

fatty streaks

early atherosclerotic lesions with flat yellow lipid deposits

fibrous atheromatous plaque

advanced lesions with lipid accumulation, smooth muscle growth and scar tissue

complicated lesion

severe lesions with hemorrhage, ulceration, scar tissue and possible rupture

major risk factors for athersclerosis

• hypercholesterolemia

• smoking

• hypertension

• family history

• age

• low HDL

• high CRP

• high homocysteine

major complications of athersclerosis

• ischemic heart disease

• stroke

• peripheral vascular disease

what is ischemia?

reduced blood flow causing tissue damage

infarction

tissue death due to lack of oxygen

common sites of athersclerosis

heart

brain

kidneys

lower extremities

small intestine

saccular aneurysm

localized outpouching of a vessel wall

fusiform aneurysm

elongated, football-shaped dilation of a vessel

dissecting aneurysm

tear within vessel wall creating a blood-filled channel; life-threatening

signs of acute arterial occlusion

• pain

• paresthesia motor weakness

• loss of pulses

• cool skin

• pallor

• cyanosis

seven P’s of acute arterial embolism

• pistol shot (sudden onset)

• pallor

• polar (cold)

• pulselessness

• pain

• paresthesia

• paralysis

vasdculitis

inflammation of blood vessels causing organ damage

systemic necrotizing vasculitis

severe vessel inflammation with tissue death

hypersensitivity vasculitis

immune-mediated vessel inflammation

giant cel arteritis

inflammatory disease of large arteries

atherosclerotic occlusive disease (PAOD)

blockage of arteries due to plaque

thromboangiitis obliterans

smoking-related inflammatory disease causing thrombus formation

raynaud disease/phenomenon

vasospasm of small arteries in fingers/toes

venous circulation

low-pressure system with valves, thin walls and reliance on skeletal muscle pump

varicose veins

stretched veins causing blood pooling and congestion

primary varicose veins

affect superficial veins

secondary varicose veins

affect deep veins

thrombophlebitis (DVT)

blood clot in a vein, often in the leg, causing swelling and edema

virchow’s triad

three factors causing venous thrombosis-stasis

hypercoagulability

vessel injury

risk factors for venous stasis

• bed rest

• immobility

• spinal cord injury

• MI

• heart failure

• shock

• venous circulation

venous insufficiency

inadequate venous return due to valve damage

vascular incompetence

loss of one-way blood flow

stasis dermatitis

skin inflammation and darkening due to blood pooling

venous ulcers

open sores caused by poor venous circulation