6/5 UWorlds Flashcards
What is a better test for hypothyroidism, TSH or T3/T4
TSH
TSH levels will rise before T4 levels fall below normal
Describe the role that troponin and tropomyosin play in muscle contraction
Tropomysin sits in the myosin-binding sites of actin
Troponin molecules are situated alongside tropomyosin
When Ca2+ binds to troponin C, the Troponin-Ca2+ complex pulls tropomyosin away, exposing the myosin-binding site
What disorder is associated with decreased levels of hypocretin
Narcolepsy
What bases (A, G, T, U) are present at the 5’ and 3’ splice site of the intron
5’ splice site = GU
3’ splice site = AG
What is the single AA mutation in sickle cell vs. hemoglobin C
Sickle cell: Glutamic acid to Valine (THINK: G and V are more far apart so more severe)
Hb C: Glutamic acid to Lysine (THNK: G and L are closer together so milder)
What is the presentation of Henoch-Schonlein purpura
- Due to IgA immune complex deposition
- Follows URI infections
- Presentation:
- Palpable purpura on buttocks and legs
- Arthralgias
- GI pain and bleeding
- Hematuria – IgA nephropathy (aka Berger disease)
Describe the origin and insertion of the ACL
- Originates on the lateral femoral condyle
- Courses anteriorly and medially to insert on the anterior intercondylar area of the tibia
Describe the origin and insert of the posterior collateral ligament (PCL)
- Originates on the medial condyle of the femur
- Courses posteriorly to the posterior head of the tibia
What are the CYP450 substrates
- Always Think When Outdoors:
- A - Anti-epileptics
- T - Theophylline
- W - Warfarin
- O - OCPs
What are the CYP450 inducers
§ Corona, Guinness, ‘N’ PBRS induce Chronic alcoholism
· C - Carbamazepine
· G - Griseofulvin
· N - Nevirapine
· P - Phenytoin
· B - Barbiturates
· R - Rifampin
· S - St. John’s Wort
· Chronic alcoholism
What are the CYP450 inhibitors
§ SICKFACES.COM:
· S - Sodium valproate
· I - Isoniazid
· C - Cimetidine
· K - Ketoconazole
· F - Fluconazole
· A - Acute alcohol abuse
· C - Chloramphenicol
· E - Erythromycin (macrolides)
· S - Sulfonamides
· C - Ciprofloxacin
· O - Omeprazole
· M - Metronidazole
What is the clinical presentation of Legionella
Atypical pneumonia
Hyponatremia
Neuro sx (HA and confusion)
Diarrhea
High fever (over 104)
What type of cardiac disease is typically associated with hemochromatosis
Dilated cardiomyopathy
What type of individuals are eligible for Medicare
Patients > 65 y/o
Patients < 65 with certain disabilities, and those with end-stage renal disease, and ALS
Describe the effects/time frame following an MI
- THINK:
- Nothing
- 1 day à Coagulative necrosis
- Inflammation
- 1 week
- Granulation tissue
- 1 month
- Scar formation
- < 4 hours
- Gross changes:
- None
- Microscopic changes:
- None
- Complications:
- Cardiogenic shock (cannot provide blood to organs)
- Congestive heart failure (decreased ejection fraction)
- Arrhythmias
- Gross changes:
- 4 – 24 hours:
- Gross changes
- Dark discoloration
- Microscopic changes:
- Coagulative necrosis (nucleus removed from dead cells)
- Contraction bands (due to reperfusion injury from hypercontraction)
- Wavy fibers with narrow, elongated myocytes
- Complications:
- Arrhythmia
- Gross changes
- 1 – 3 days:
- Gross changes
- Hyperemia
- Microscopic changes:
- Neutrophils
- Complications
- Fibrinous pericarditis (neutrophils attaching the dead heart will leak out into pericardium)
- Presents as chest pain with friction rub
- Fibrinous pericarditis (neutrophils attaching the dead heart will leak out into pericardium)
- Gross changes
- 4 – 7 days:
- Gross changes:
- Yellow pallor (due to WBC)
- Microscopic changes
- Macrophages
- Complications
- Rupture of ventricular free wall can lead to cardiac tamponade
- Rupture of interventricular septum
- Rupture of papillary muscle (fed by R coronary artery) leading to mitral insufficiency
- Gross changes:
- 1 -3 weeks:
- Gross changes:
- Red border emerges as blood vessel from normal tissue grow into necrotic tissue to form granulation tissue
- Microscopic changes:
- Granulation tissue with fibroblasts, collage, and blood vessels
- Complications:
- Arrhythmias
- Gross changes:
- Months:
- Gross changes
- White scar
- Microscopic changes:
- Fibrosis
- Complications
- Aneurysm (scar is not as strong as myocardium)
- Mural thrombus and embolism (secondary to aneurysm)
- Dressler syndrome (antibodies against pericardium) occurring 6-8 weeks after infarction
- Chest pain, pericardial friction, and persistent fever
- Gross changes
What disease typically presents with anemia, renal insufficiency, back pain, and hypercalcemia
Multiple myeloma:
- Malignant proliferation of monoclonal plasma cell within the marrow
- Recall: Plasma cells = mature B-cells that produce immunoglobulin
- M spike
- Classic presentation:
- Anemia – plasma cells packed in bone marrow inhibit production of other cells (Rouleauz formation)
- Renal insufficiency – excessive antibodies plug up kidney and form casts
- Back pain – plasma cells activate osteoclasts
- Hypercalcemia – plasma cells stimulate osteoclasts
What are the 2 types of gastric cancer
Intestinal and diffuse
Which gastric cancer is associated with H. Pylori and chronic gastritis
Intestinal type
What is a characteristic carcinogen associated with i_ntestinal type_ gastric cancer
Nitrosamines (smoked foods)
This is why intestinal gastric cancer is so prevalent in Japan