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Pathophysiology Porth's Ch. 30 Disorders of Blood Flow

Terms in this set (27)

Disorders of arterial circulation
- atherosclerosis
- vasculitis
- arterial disease of the extremities
- arterial aneurysms
Arteriosclerosis
term to describe any hardening (and loss of elasticity) of medium or larger arteries
arteriolosclerosis
hardening (and loss of elasticity) of arterioles (small arteries)
atherosclerosis
- progressive disease characterized by hardening of an artery specifically d/t an atheromatous plaque
- including aorta, coronary arteries, and cerebral vessels
- major risk factors: hypercholesterolemia, inflammation
atherosclerosis- etiology and risk factors
- Hypercholesterolemia: High LDL
- Cigarette smoking
- Hypertension
- Family history
- Age (men ≥45 years; women ≥55 years)
- Diabetes mellitus
- Obesity
- C-reactive protein
- Homocysteine levels
- Serum lipoproteins
- Infectious agents
atherosclerosis- pathogenesis
3 Types of Lesions:
1) Fatty streaks - Thin, flat yellow intimal discolorations that progressively enlarge
2) Fibrous atheromatous plaque - The accumulation of intracellular and extracellular lipids, proliferation of vascular smooth muscle cells, and formation of scar tissue
3) Complicated lesion - Contains hemorrhage, ulceration, and scar tissue deposits
atherosclerosis- complications
Outcomes:
- Ischemic heart disease
- Stroke
- Peripheral vascular disease
Complications:
- Narrowing of the vessel and resulting ischemia
- Vessel obstruction due to plaque hemorrhage or rupture
- Thrombosis and formation of emboli
- Aneurysm formation
Specific arterial involvement in atherosclerosis
Larger vessels:
- Thrombus formation
- Weakening of the vessel wall
Medium-sized arteries:
- Ischemia and infarction
- Vessel occlusion
- Arteries supplying the heart, brain, kidneys, lower extremities, and small intestine are most frequently involved.
stroke
pieces of plaque can break free, travel to the brain, and block blood vessels that supply blood to the brain
atherogenic
used for substances or processes that cause atherosclerosis
atherogenesis
developmental process of atheromatous plaques
vasculitis
- An inflammation of the blood vessel wall resulting in vascular tissue injury and necrosis
- Arteries, capillaries, and veins may be affected
- The inflammatory process may be initiated by direct injury, infectious agents, or immune processes
Arterial disease of the extremities
Acute Arterial Occlusion:
- Sudden event that interrupts arterial flow to the affected tissues or organ
- Embolus or thrombus
Atherosclerotic occlusive disease:
- Progressive narrowing of the arteries in the lower extremities
Peripheral Arterial Disease (PAD)
7 "P's" of Acute arterial embolism
1) Pistol shot (acute onset)
2) Pallor
3) Poikilothermia or Polar (cold)- blood vessels vasodilate in leg in attempt to give blood flow
4) Pulselessness
5) Pain
6) Paresthesia
7) Paralysis
* necrosis usually develops at bottom of toe and goes up
Peripheral arterial narrowing
S/s of ischemia typically correspond to the area of arterial stenosis
1) obstruction in the aorta or iliac artery causes ischemia ***********, male reproductive parts, or thighs
2) narrowing of the femoral artery or its branches affects the thigh or calf
3) obstruction in the popliteal artery affects the calf, ankle or foot
Peripheral vascular disease- clinical manifestations
- Intermittent claudication
- Rest pain
- Diminished pulses
- Cold/cool skin
- Elevation pallor
- Persistent cyanosis
- Dependent rubor
- Hair loss
- Thicken toenails
- Chronic ulcers
- Paresthesias
Arterial disease of the extremities- Thromboangiitis obliterans
Inflammatory arterial disorder that causes thrombus formation ; occurs in fingers and toes
Arterial disease of the extremities- Raynaud disease and phenomenon
- Intense vasospasm of the arteries and arterioles in the fingers and, less often, the toes
- fingers become white d/t lack of blood flow, then blue as vessels dilate to keep blood in tissues, finally red as blood flow returns
aneurysms
- Abnormal localized dilatation of an artery due to a weakness in the vessel wall
- As the aneurysm increases in size, the tension in the wall of the vessel increases, and it may rupture
- The increased size of the vessel also may exert pressure on adjacent structures
Berry aneurysm
- Most often found in the circle of Willis in the brain circulation
- Consists of a small, spherical vessel dilation
Fusiform
- Most often found in the thoracic and abdominal aorta
- Characterized by gradual and progressive enlargement of the aorta
pseudoanerurysm
- top of aneurysm isn't actually vessel wall
- has no intact layer of vessel wall, unlike true aneurysm in which outer layer or adventia, is still intact
- hole doesn't seal right away
dissecting aneurysm
- Acute, life-threatening condition
- Involves hemorrhage into the vessel wall with longitudinal tearing (dissection) of the vessel wall to form a blood-filled channel
Aortic aneurysms/dissections etiologies
- Arteriosclerosis
- Hypertension
- Infection
- Trauma
- Connective Tissue Disorder
- Pregnancy
- Iatrogenic Causes
Disorders of the venous circulation
- Produce congestion of the affected tissues
- Predispose to clot formation because of stagnation of flow and activation of the clotting system
- Types of disorders:
- Varicose veins
- Chronic venous insufficiency
- Venous thrombosis
incompetent venous valve
blood flows backward away from the heart and into the superficial system causing venous congestion and high pressures within the superficial veins
venous thromboembolism
- result of clot formation in venous circulation
- manifests as DVT or PE
- develops as a result of 3 primary components known as Virchow's triad: venous stasis, vascular injury, hypercoagulability
- best intervention is to get them up and out of bed
THIS SET IS OFTEN IN FOLDERS WITH...