NBME High Performing Summary for the final Exam preparation 2023/2024

What are sentinel lymph nodes? First group of lymph nodes draining a specific organ Describe the lymph node drainage of the GI tract *Trachea and esophagus => Mediastinal *Liver, spleen, pancreas, stomach, upper duodenum => Celiac *Lower duodenum, jejunum, ilecum, colon to splenic flexure => SMA *Colon from splenic flexure to upper rectum => IMA *Lower rectum to anal canal (above pectinate line) =>Internal Iliac Anal rectum (below pectinate line) =>Superficial inguinal What is the mechanism by which Lactulose is used to treat Hepatic Encephalopathy? *Lactulose is resistant to intestinal disaccharides *Metabolized by gut flora into lactic and formic acid. *These acids have an osmotic/laxative effect and cause an acidifying effect *Acids also cause NH3 to be trapped as NH4+ and cannot cross intestinal wall; excreted into feces What antimuscarinics are used to prevent postprandial abdominal pain of IBS patient Hyoscyamine,dicyclomine Which drugs are contraindicated in patients with glaucoma? Drugs that cause mydriasis: A1 agonists or M3 antagonists (antimuscarinics) A1 agonists: Epinephrine M3 antagonists:Atropine and other antimuscarinics Mydriasis pulls the iris to it's base, making the angle narrow What is the treatment of Atropione poisoning? What is the treatment of Organophosphate poisoning? Atropine poisoning: Physostigmine (crosses BBB) Organophosphate poisoning: Atropine first and then PAM *Important to distinguish between atropine overdose and TCA overdose. Both have symptoms of anticholinergic excess; TCA also has Which receptor is associated with the following *Pupillary dilator muscle contraction -> mydriasis *Pupillary sphinctor muscle contraction -> miosis *Ciliary muscle contraction ->accommodation *Increase aqueous humor production *Decrease aqueous humor production *Pupillary dilator muscle contraction -> mydriasis: A1 *Pupillary sphinctor muscle contraction -> miosis: M3 *Ciliary muscle contraction ->accommodation: M3 *Increase aqueous humor production: B2 *Decrease aqueous humor production: A2 Hemicholinium MOA: blocks the sodium-dependent reuptake of choline into presynaptic terminals. *Because reuptake of choline is the rate-limiting step in acetylcholine synthesis, hemicholinium reduces presynaptic stores of acetylcholine Which of the following below will deplete "presynaptic ACh" stores? a) botulinum toxin b) curare c) neostigmine d) hemicholinium e) atropine d) hemicholinium A 47-year-old woman comes to the physician for a routine health maintenance examination. She has a 2- year history of venous insufficiency and notes daily swelling of her ankles that worsesn in the evening. She takes no medications. Her pulse is 80/min, and BP is 160/100 mm Hg. Cardiopulmonary examination shows no abnormalities. Examination of the lower extermities show 2+ edema and increased pigmentation. Which of the following hypertensive drugs would most likely exacerbate this patient's swelling? A) Atenolol B) Clonidine C) Lisniopril D) Losartan E) Nifedipine E) Nifedipine Bilateral edema of the lower limbs is one of the most common adverse effects of DHPs and is likely related to the vasodilatory mechanism of action