NUR 612 FINAL PATHOPHYSIOLOGY SUMMARY

Anatomy Review ● Blood Vessels: ○ Arteries: Round, thick, pulsatile, carry blood away from heart, more smooth muscle (media) than vein ○ Veins: Wider, irregular, have valves that allow for return of blood to heart ○ Capillaries: Gas exchange, small, friable ○ Three layers of tissue for arteries and veins: ■ Tunica Intima: Endothelial cells, immunity and coagulation, problems here→ HTN, atherosclerosis ■ Tunica Media: Smooth muscle cells, activated during SNS ● Alpha 1 activation→ Vasoconstriction ● Alpha 2 activation→ Vasodilation, decreased release of norepinephrine ■ Tunica Externa: Collagen and elastic fibers, accommodates amount of blood ● Endothelial Cells ○ Control transfer of molecules across vascular wall→ endothelin (vasoconstricts), nitric oxide (vasodilates) ○ Control of platelet adhesion, blood clotting, immune and inflammatory reactions ○ Modulation of blood flow and vascular resistance, metabolism of hormones, influence growth of other cells ● Endothelial Dysfunction ○ Root cause of many diseases like HTN, but also worsen these so it’s a cyclical process ○ Potentially reversible, may be due to HLD, smoking, infections/inflammation (cytokines, bacteria, virus), hypoxia, hemodynamic stresses Aneurysms ● Areas of arterial walls that balloon outward due to weakening→ rupturing or leaking ● Most common causes: Atherosclerosis (endothelial tissue) and HTN (increased force), Marfan’s, smoking increases rupture risk and causes endothelial injury (esp males 50 years old) ● True aneurysms: Affect all three layers of the vessel→ saccular (one side) and fusiform (both sides) ● False aneurysms: Vessel damage and blood leakage or dissection→ extravasation of blood ○ Aortic Dissection: Acute, life-threatening - hemorrhage into vessel wall with tearing→ blood-filled channel ■ Risk factors: HTN, degeneration medial layer of vessel wall ■ Manifestations: Sudden onset excruciating pain “tearing, ripping” ● Type A: Chest pain, stroke-like s/s (upper area of aorta affected) ● Type B: Pain to back, may have loss/different pulses in extremities ● Type A will become Type B→ BBs help slow down ■ Early Stage: Blood pressure moderate/markedly elevated ■ Late Stage: Marked Hypotension ■ Syncope, Hemiplegia, loss of pulse or paralysis of the lower extremities may occur. ○ Diagnosis: DILIGENT physical exam, Aortic Angiography, CT, MRI ○ Treatment: BP Control (BBs), immediate surgery (prosthetic graft)! ● Clinical Manifestations: Vary widely, may be asymptomatic unless rupturing/dissecting ○ Thoracic Aneurysm: (10%) ■ Chest/neck/back/shoulder pain ■ Dyspnea, stridor, cough, pressure on trachea, hoarseness (laryngeal nerve damage), dysphagia (pressure on esophagus) ○ Abdominal (90%) ■ Pulsatile mass (usually below the renal artery), aortic diameter 3cm, bruit in abd area ■ Abd, flank or back pain ○ Cerebral: HA, increased ICP- hemorrhagic stroke