5/18 UWorld Flashcards
What is the presentation of multiple sclerosis
- Charcot triad of symptoms - SIN:
- Scanning speech
- Intention tremor, Incontinence, Internuclear ophthalmoplegia
- Nystagmus
- Hemiparesis, hemisensory symptoms
MRI findings in multiple sclerosis
Periventricular plaques (areas of oligodendrocyte loss and reactive gliosis)
Describe the mechanism behind glucagon as a treatment for beta blocker toxicity
Glucagon acts on G-protein coupled receptors, increasing intracellular cAMP, and thus increasing release of intracellular calcium during muscle contraction
This increases heart rate and cardiac contractility
What are the 2 types of epithelium in Meckel diverticulum
Gastric and pancreatic
What are the branches of the celiac trunk
- Common hepatic artery
- Gastroduodenal artery
- R gastroepiploic - greater curvature of stomach (anastomoses with L gastroepiploic)
- Anterior superior pancreaticoduodenal à head of pancreas, proximal duodenum
- Right gastric artery - lesser curvature of stomach (anastomoses with L gastric a.)
- Proper hepatic artery
- Gastroduodenal artery
- Splenic artery - spleen
- Left gastroepiploic artery - greater curvature of stomach
- Left gastric artery - lesser curvature of stomach
What are the actions of angiotensin II
- (1) Acts on the zona glomerulosa cells of the adrenal cortex to stimulate synthesis of aldosterone
- Aldosterone acts on principal cells of renal distal tubule and collecting duct to increase Na+ reabsorption and increase K+ and H+ excretion
- (2) Stimulates Na+/H+ exchange in the renal proximal tubule
- Leading to increased reabsorption of Na+ and HCO3-
- (3) Acts on the hypothalamus
- Increases thirst and water intake
- Increases release of ADH
- (4) Acts directly on arterioles to cause vasoconstriction
- Leads to an increase in TPR à increased BP
- (5) Constricts efferent arteriole of the glomerulus
- Increases filtration fraction to preserve renal function (GFR) in low volume states
How does Hepatitis D use Hepatitis B in order to cause infection
- Hepatitis D antigen must be coated with Hepatitis B surface antigen (HBsAg) in order to penetrate the hepatocyte to cause infection and multiply
Cause of gastric varices within the fundus
Portal HTN
Splenic vein thrombosis (often due to pancreatitis, pancreatic cancer, or abdominal tumors - splenic vein runs posterior to pancreas)
Describe the relationship between Creatinine and GFR
- When GFR is normal, relatively large decreases in GFR result in only small increases in serum creatinine
- A person’s serum Cr can be essentially normal even after 50% loss of kidney function
- Cr levels begin to rise significantly as the GFR declines to <60%
- As the GFR continues to decline, the slope of the Cr curve steepens
What is the formula for filtration fraction?
FF = RPF/GFR
Describe the adenoma-to-carcinoma sequence of colorectal cancer
- Normal colon
- APC (adenomatous polyposis coli) gene mutation
- Colon at risk for polyps
- KRAS mutation
- Development of polyps/adenoma
- p53 mutation (loss of tumor suppressor) + increased expression of COX
- Progression to carcinoma
Describe Displacement vs. Projection
- Displacement
- Transferring avoided feeling or ideas to a neutral person
- E.g. Father yells at child because his boss yelled at him
- Projection
- Attributing unacceptable internal impulses to an external source
- E.g. Accusing wife of cheating because of your desire to cheat
Describe Isolation (psych)
- Separating feelings from ideas and events
- E.g. Describing murder in detail without an emotional response
What is reaction formation
- Unconsciously replacing warded-off feelings by emphasis on its opposite
- E.g. Really sexual person become a monk
Describe sublimation (psych)
- Consciously replacing an unacceptable wish with a similar but acceptable course of action
- E.g. Redirection of aggression towards father into sports
What drugs can be used for nocturnal enuresis?
- Imipramine:
- TCA
- Decreases Non-REM N3
- Short-term treatment
- Desmopressin
- Decreases urination
- Indomethacin:
- Decreases renal blood flow, thus decreasing urine formation
What is the cavernous sinus and what does it contain?
- Collection of venous sinuses on either side of pituitary
- Contains CNs III, IV, V1, VI, and occasionally V2, + internal carotid
- Cavernous sinus syndrome:
- Can be due to pituitary tumor, infection
- Presentation:
- Ophthalmoplegia (CN II, IV, VI)
- Decreased corneal sensation (CN V1)
- Horner syndrome
- Decreased maxillary sensation (CN V)