UWorld Exam 2 Section 1, 2, 3 Flashcards
What is the most common cause of mitral stenosis?
Chronic rheumatic fever
What type of HSR is rheumatic fever?
Type II HSR
Antibodies to M protein cross-react with self antigen
What is anisocoria
unequal pupil size
What nerve/ganglion is affected in a Pancoast tumor in order to cause Horner syndrome?
Cervical ganglion
What is the cause of S3 heart sound?
Rapid flow of blood from atria to ventricles
Occurs with volume overload (e.g. CHF, mitral or tricuspid regurg)
What is the cause of S4 heart sound
Atrial contraction against a stiff ventricle (e.g. hypertrophic cardiomyopathy)
What is the genetic defect and associated cancers of Lynch syndrome
Mutation in mismatch gene repair
Cancers: colorectal, endometrial, ovarian
What is the defect and associated triad in Ataxia telangiectasia?
Defect in ATM gene - failure to repair DNA double strand breaks
Triad: ataxia, telangiectasia, IgA deficiency
What are some drugs that inhibit calcineurin
(Names, MOA, uses, toxicity)
- Cyclosporine
- Immunosuppressant
- Blocks lymphocyte activation and proliferation
- MOA:
- Binds cyclophilin (protein within cytosol of T-cells)
- Inhibits calcineurin (which stimulates IL-2) à prevention of IL-2 transcription
- Uses:
- Transplant rejection
- Psoriasis
- Rheumatoid arthritis
- Toxicity
- Nephrotoxicity
- Immunosuppressant
- Tacrolimus
- Immunosuppressant
- Blocks lymphocyte activation and proliferation
- MOA:
- Binds FK506 binding protein
- Inhibits calcineurin à prevention of IL-2 transcription
- Uses:
- Transplant rejection prophylaxis
- Toxicity:
- Nephrotoxicity
- Immunosuppressant
What are the complications associated with alkaptonuria
o Blueish-black connective tissue (e.g. ear cartilage) and sclera
o Black urine upon prolonged exposure to air
o Debilitating arthralgias
What is the difference in lens subluxation between Marfan’s and homocystinuria
Marfan - upward
Homocysteinuria - down and in
Compare and contrast presentation of Marfan vs. Homocystinuria
o Marfan:
§ Marfanoid habitus (pectus deformity, tall stature, arachnodactyly, joint hyperlaxity, skin hyperelasticity, scoliosis)
§ Normal intellect
§ Aortic root dilation
§ Upward lens dislocation
o Homocystinuria:
§ Marfanoid habitus
§ Intellectual disability
§ Thrombosis
§ Downward lens dislocation
§ Megaloblastic anemia
§ Fair complexion
Are water-soluble or lipid-soluble molecules more likely to cross the placenta
Lipid soluble
So it is safer to give water-soluble drugs during pregnancy
Describe the pathophysiology of exophthalmos in Graves disease
- Lymphocytes infiltrate the orbital tissues and secrete cytokines that stimulate fibroblasts to secrete increasing amounts of glycosaminoglycan ground substance such as hyaluronic acid. This increased hyaluronic acid draws water into the orbit resulting in extraocular muscle edema. Combined with interstitial edema, this process pushes the globe outward (proptosis). A sensation of grittiness and excessive tearing occur because the lids are now unable to completely cover the proptotic globe. Desiccation and keratitis may result
Describe jugular venous tracing graph
What are the names of some high potency first generation antipsychotics
Haloperidol
Fluphenazine
Trifluoperazine
What are the names of some low potency first generation antipsychotics?
Thioridazine
Chlorpromazine
Describe the control of lac operon expression
- Lac operon controls the expression of beta-galactosidase (necessary for lactose metabolism) in order to ensure that glucose is used preferentially over lactose
- CAP is the transcription factor that determines if the gene is transcribed or not
- When glucose is low, CAP will be activated and there will be increased transcription
- Repressor proteins are present (and block binding of RNA polymerase and initiation of transcription) unless lactose is high
- When lactose is high, repressor protein will unbind from the operator site, and transcription will be increased
- So ideal transcription occurs when there is low glucose (à increased CAP) and high lactose (à decreased repressor protein)
What is the most important risk factor for thyroid malignancy?
Radiation exposure
What will be the effect/presentation of dopamine beta-hydroxylase deficiency?
· Impaired synthesis of norepinephrine and epinephrine leading to impaired sympathetic adrenergic activity
· May present with hypotension, exercise intolerance, nasal congestion, and ejaculatory difficulties
Which lung volume will be increased in COPD?
Residual volume (RV)
What are the causes of R shift of O2-Hb dissociation curve
- Shifts to the R (lower binding affinity – unloading of O2) – think of muscles working hard
- Increased pCO2
- Decreased pH (due to increased CO2)
- Increased temperature
- Increased 2,3-DPG
- This is a byproduct of glycolysis, which increases under hypoxic conditions
- 2,3-DPG will bind to beta chains and reduce their affinity for O2
Describe the defect in medium-chain acyl CoA dehydrogenase deficiency (MCAD)
- Deficient enzyme for beta-oxidation -> decreased ability to breakdown fatty acids into acetyl-CoA -> accumulation of fatty acyl carnitines in blood with hypoketotic hypoglycemia
- Presentation:
- Vomiting, lethargy, seizures, coma, liver dysfunction
- Can lead to sudden death in infants or children
- Treatment:
- Avoid fasting
What structures exit the 3 different opening of the diaphragm?
- Vena caval formamen (caval opening) – contains IVC
- Aortic hiatus – contains aorta thoracic duct, azygos vein
- Esophageal hiatus – contains esophagus and anterior and posterior trunks of the vagus nerve
