Set 13 Flashcards
You recommend that your patient, a 51-year-old woman, begin taking a calcium and vitamin D supplement in order to prevent osteoporosis. What are the steps in the conversion of vitamin D to its active form in the body? By what mechanism does vitamin D help prevent osteoporosis?
D3 from sun exposure in skin, D2 ingested from plants. Requires two hydroxlations in the body to become active. Both converted to 25-OH (calcidiol) in liver and 1,25(OH)2 (calcitriol - active form) in kidney
Increases absorption of dietary calcium (put into bone) and phosphate.
A child arrives at the ER in hypotensive shock after taking his dad’s phenoxybenzamine. The intern on call orders the nurse to get her a pressor STAT. The nurse informs the intern that there are two pressors available in the ER, epinephrine and phenylephrine. Which one will be able to increase the blood pressure of this pediatric patient?
Phenoxybenzamine is an irreversible nonselective alpha blocker used preoperatively to prevent catecholamine (HTN) crisis in patients with pheochromocytoma.
Phenylephrine will be able to increase the blood pressure because it is a pure a-agonist without B action. Epinephrine has alpha and beta agonist action so it will show a depressor effect (decrease BP) —> with the alpha action blocked beta becomes more prominent (B2 on vascular smooth muscle - peripheral vasodilation)
At times bupropion can be added to a selective serotonin reuptake inhibitor (SSRI) for treatment- resistant depression. What can occur if a MAO inhibitor (MAOI) is added to an SSRI? What is the treatment for this condition?
Buproprion: Atypical antidepressant. Increases NE and DA via unknown mechanism
Serotonin syndrome: can occur with any drug that increases 5-HT (MAOi, SNRI, TCA) - hyperthermia, confusion, hyperreflexia, myoclonus (muscle rigidity), cardiovascular collapse, flushing, diarrhea, seizures, agitation
Treatment: stop serotonergic drugs, sedate with benzodiazepine (lorazepam), supportive care and cyproheptadine (5-HT2 receptor antagonist)
What landmarks are used when placing an internal jugular central venous catheter?
Sternocleidomastoid muscle (two heads - sternal and clavicular) + clavicle form triangle —> place needle at apex of that triangle (30 degree angle) and aim needle at nipple. Always palpate carotid artery to avoid!
A patient presents with a 1cm painless, mobile mass in her right parotid gland. You inform the patient that most tumors in the parotid gland are benign. What is the most common benign tumor of the salivary gland? What is a Warthin’s tumor? What cranial nerve goes through the parotid gland?
Pleomorphic adenoma (benign mixed tumor): the most common salivary gland tumor. Presents as a painless, mobile mass. It is composed of chondromyxoid stroma and epithelium and recurs if incompletely excised or ruptured intraoperatively
Warthin tumor: (papillary cystadenoma lymphomatosum) a benign cystic tumor with germinal centers (heteropic lymphoid tissue inside salivary gland tissue, which can form germinal centers) - like a lymph node trapped in the parotid gland
Facial nerve (VII) courses through parotid gland but does not innervate it
Clavulanic acid, sulbactam, and tazobactam aid penicillins in their activity against bacteria through what mechanism?
B-lactamase inhibitors (CAST): Have a beta lactam ring that helps prevent cell wall synthesis. Often added to penicillin antibiotics to protect the antibiotic from destruction by B-lactamase that breaks down the beta lactam ring (penicillinase)
Which bacteria are most commonly responsible for sialadenitis? What condition most commonly predisposes a patient to sialadenitis?
Staph aureus
Viridans strep
Stone obstruction of the salivary gland duct (sialolithiasis)
Membranous glomerular diseases involve thickening of what structure?
Glomerular basement membrane
An 88-year-old man arrives at the ER after he fell and struck his head. He has a history of atrial fibrillation, for which he takes warfarin. Noncontrast CT of the head reveals subarachnoid hemorrhage. What is the antidote for warfarin anticoagulation or warfarin overdose? For heparin overdose?
Warfarin: IV vitamin K (takes days) -and fresh frozen plasma (give coagulation factors)
Heparin: Protamine sulfate
What important secretory products are secreted from the following cells of the GI tract? G cells I cells S cells D cells Parietal cells Chief cells
G cells: Gastrin I cells: CCK S cells: Secretin D cells: Somatostatin Parietal cells: Gastric acid and intrinsic factor Chief cells: Pepsin
