Pathology of Vessels

Arteries

• small arteries <2 mm
• arterioles 20-100 um
• capillaries 7-8 um (diameter of rbc)

Hypertension

• essential- cause unknown
• secondary 
• renal causes
• endocrine causes; e.g., pheocromocytoma, hyperaldosteronism
• neurologic; e.g., psychogenic
• cardiovascular
• malignant - medical emergency
• vascular pathology
• arteriosclerosis & glomerulosclerosis
• hyperplastic arteriosclerosis in malignant hypertension -  "onion skin" lesions
• complications
•  atherosclerosis
• aortic dissection
• cardiac hypertrophy
• nephropathy
• stroke (ischemic and hemorrhagic)

Vasculitis - inflammation of blood vessels

• constitutional - non-specific; fever, malaise, arthralgias, myalgias
• specific blood vessel dependent; CNS, bowel
• infectious
• non-infectious (immunologic)
• large vessel vasculitis
• giant cell arteritis
• temporal artery tenderness
• opthalmic, vertebral, aorta 
• can lead to blindness
• Takayasu arteritis
• fibrous thickening of aortic arch
• weak upper extremity pulses but intact in feet
• Syphillitic aortitis
• infection concentrates around vaso vasorum. leads to infarction of aortic media
• leads to aneurysms
• dilates aortic root - leads to aortic regurgitation
• medium vessel vasculitis
• Polyarteritis nodosa
• renal and visceral vessels
• inflammation destroys vessel walls - creates nodules
• pulmonary vessels spared
• blockage -ischemia 
• pathogenesis
• Kawasaki disease
• mucocutaneous lymph node syndrome
• arteritis affecting coronary arteries - leads to coronary artery aneurysms
• leading cause of acquired heart disease in children
• viral trigger?
• small vessel vasculitis
• Wegener's granulomatosis
• Triad
• necrotizing granulomas of upper respiratory tract, lung
• necrotizing vasculitis - lung
• necrotizing glomerulitis
• Churg-Strauss Syndrome (rare)
• allergic granulomatosis
• vasculitis with eosinophilia

Veins

• varicose veins
• thrombophlebitis & phlebothrombosis - development of thrombi
• Virchow's triad
• superior & inferior vena cava syndrome
• invasion by tumor 
• compression by tumor