Vessels UWorld 2 Flashcards
ApoA-1
LCAT acivation, cholesterol esterification
Chylomicrons and HDL
Defect in ApoE3 and ApoE4
Familial dysbetalipoproteinemia. Liver cannot remove chylomicrons and VLDL remnants from cirulation –> serum cholesterol and triglyceride elevation. Xanthomas and premature heart and vessel disease
ApoB-48
Chylomicron assembly and secretion by intestine
Chylomicron and remnants
ApoB-100
Binds LDL receptor, LDL uptake by extrahepatic cells
VLDL, IDL, LDL
ApoC-II
Lipoprotein lipase activation
Chylomicron, HDL
ApoE
VLDL, chylomicron uptake by liver
Chylomicron, remnant, VLDL, IDL, HDL
Dilated tortuous veins: risk factors, complications
Varicose veins. Long periods of standing, age, obesity, multiple pregnancies, genetic defects.
Complications include painful thromboses, skin ulcerations, dermatitis, infection, poor wound healing
Embryonic vein derivatives: vitelline, umbilical, cardinal
Vitelline –> portal
Umbilical degenerate
Cardial –> systemic
Atherosclerosis begins with injury to which cell type?
Repetitive endothelial injury, leads to chronic inflammatory state in the intima
What meds cause hyperkalemia
Things that interfere with aldosterone (ACE-I, ARBs, K-sparing diuretics, NSAIDs)
Cardiac glycosides
Non-selective beta blockers
After endothelial injury, what causes intimal thickening?
Smooth muscle cells, collagen deposition. Intimal hyperplasia and fibrosis results.
Earliest lesion of atherosclerosis
Intimal fatty streaks of intimal lipid-filled foam cells
What makes up foam cells?
Macrophages and smooth muscle cells that have engulfed LDL
Equation for net filtration pressure
Hydrostatic pressure gradient - oncotic pressure gradient
Side effects of niacin (B3)
Exacerbates gout, acanthosis nigricans (hyperglycemia), red flushed face/vasodilation, hepatitis
What meds increase serum uric acid levels?
Niacin, hctz, cyclosporine, pyrazinamide
Most important risk factor for aortic dissection
hypertension
Why do ACE inhibitors increase serum creatinine? What affect does this have in pts with renal artery stenosis?
Reduce ATII, causing decreased efferent arterial tone –> efferent dilation. Decreases glomerular pressure and renal perfusion. Pts with renal artery stenosis are dependent on efferent constriction to keep perfusion high, so this can cause renal failure
Statins decrease cholesterol synthesis. What is the LDL receptor response?
Increased receptor density
What is abnormal in varicose veins?
Incompetent venous valves –> venous hypertension, retrograde flow from deep to superficial veins in extremities
What tissue extracts the most oxygen from blood?
Heart. 75-80% at rest, up to 90% with exercise
What 2 lipid lowering agents can cause gallstones?
Fibrates and bile acid resins
Genomic imprinting
An offspring’s genes are expressed in a parent specific manner. Produced by methylation (epigenetics)
Alpha 1 agonist: effects on heart
Directly increases contractility, but that is usually overridden by reflex decreases in rate, conduction, and contractility due to contraction of vascular smooth muscle
Cystic medial degeneration
Myxomatous changes in large arteries. Fragmentation of elastic tissue, separation of elastic and fibromuscular components of media by small spaces filled with extracellular matrix.
Seen in Marfan syndrome
Hyaline arteriolosclerosis: describe it, and who does it happen to
Homogenous deposition of eosinophilic hyaline material in intima and media of small arteries/arterioles. Lumen is narrowed.
Seen in non-malignant hypertension and diabetes
Compare and contrast giant cell arteritis and Takayasu arteritis
Both have granulomatous inflammation of media
GC affects branches of carotid artery, older patients.
T affects arch of aorta and proximal great vessels
What vessels are spared in polyarteritis nodosa?
Pulmonary
Norepinephrine extravasation
NE leak causes a1 vasoconstriction which can lead to local necrosis. Presents as cold, hard, pale local tissue. Can be prevented with an alpha blocker, such as phentolamine (must be done within 12 hr)
Alpha blockers (2 non selective, 2 a1, 1 a2)
Nonselective: Phenoxyenzamine (irreversible), phentolamine (reversible)
a1: Prazosin (other -zosins), tamsulosin
a2: Mirtazapine
Buerger disease aka thromboangiitis obliterans
Seen in heavy smokers (tobacco hypersensitivity) with early onset
Segmental thrombosing vasculitis, intermittent claudication. Found in medium vessels, seen often in calf, foot, hand. May extend into contiguous veins and nerves
Platelet involvement in atherscerosis
Endothelial dysfunction promotes platelet adhesion, aggregation, and release of GF and cytokines. PDGF is released by platelets as well as endothelial cells and macrophages. It promotes proliferation and migration of smooth muscles cells into intima. Platelets also secret TGF-b, which calls in smooth muscles cells and collagen production
Tx of anaphylactic shock
Epinephrine
Stimulates a1 - counteracts vasodilation, increases BP
B1 effects also raise BP and improve perfusion
B2 - bronchdilation
ACE-I causes facial swelling and difficulty breathing. What happened?
Angioedema - swelling of tongue, lips, eyelids, laryngeal edema, difficulty breathing. Due to bradykinin accumulation. Rare.
What prevents cerebral hypoperfusion upon standing?
a1-vasoconstriction
Anti- glomerular basement membrane antibodes
Goodpasture’s
Anti-neutrophil antibodies and URI
Wegener’s granulomatosis with polyangiitis
Migratory thrombophlebitis
Trousseau’s syndrome. Think visceral cancer! Hypercoaguability is a common paraneoplastic syndrome, especially in pancreas, colon, lung
Niacin effects on hypertension, diabetes
Potentiates anti-hypertensives via vasodilation
Increased insulin resistance and acanthsis nigricans
Effects of epinephrine
a1, b1, b2 agonist, a1 predominates at high dose
Raises HR (b1) Raises systolic BP (b1 and a1) Low dose decreases diastolic BP (b2) High dose increases diastolic BP (a1)
What receptors does phentolamine hit?
Non specific alpha blocker –> decrease in diastolic BP and reflex tachycardia
What receptors does phenylephrine hit?
Selective a1 agonist –> vasoconstrictor
What receptors does propanolol hit?
Nonselective beta blocker
What receptors does isoproterenol hit?
Non-selective beta agonist –> increases HR and contractility, vasodilation
What receptors does atropine hit?
Muscarinic antagonist. Increases HR by blocking vagal stimulation
Treatment of high LDL
Diet exercise, statin, ezetimibe
Tx of high triglycerides
Diet exercise, fibrate, niacin
Tx of low HDL
Diet/exercise, niacin
Timeline for strawberry heangioma
Present at birth, initially grow with child, and fade after a few years. Most are gone by age 7
Dipyridamole, cilostazol: mechanism, use, toxicity
Inhibit phosphodiesterase, which leads to increased cAMP and decreased aggregation. Cilostazol is also a direct vasodilator. Can be used for intermittent claudication, peripheral artery disease, prevention of stroke, angina prophylaxis. Toxicity includes nausea, headache, flushing, hypotension, abdominal pain
Ticlopidine, clopidogrel, prasugrel, ticagrelor
ADP receptor inhibitors, prevent GP2b3a from binding fibrinogen
Used for acute coronary syndrome, coronary stenting. Ticlopidine causes neutropenia.
Can cause TTP/HUS
Nitroprusside altered mental status, lactic acidosis
Cyanide toxicity. Treat with sodium thiosulfate. Sulfur helps the liver metabolize and detox cyanide to thiocyanate
