UWorld Practice Test #1 Flashcards
How is diabetic nephropathy characterized histologically? What if the sclerosis is nodular in nature?
Mesangial expansion, glomerular basement membrane thickening and glomerular sclerosis. If sclerosis is nodular in nature, this is called and Kimmelstiel-Wilson lesion.
Order atrial muscle, ventricular muscle, the purkinje system and the AV node from fastest to slowest in terms of conduction velocity?
Fastest to slowest: purkinje –> atrial muscle –> ventricular muscle –> AV node.
Where is the AV node located?
Along the interatrial septum, near the tricuspid orifice.
What bone tumor is most commonly associated w/ Paget’s disease?
Osteosarcoma.
Where does osteosarcoma like to occur and what is the typical radiographic pattern?
Likes to occur at the metaphysis of long bones (femur, humerus, tibia, etc.). Radiography shows mixed radiodense and radiolucent areas, periosteal new bone formation, lifting of the cortex, Codman’s triangle, and the adjacent soft tissue may have a sunburst pattern on X-ray.
What is globus sensation?
It is the abnormal feeling of foreign body, tightness or fullness of the throat that does not have accompanying physical, endoscopic or radiographic findings of esophageal obstruction.
What characterized pseudobulbar palsy and what causes it?
Characterized by dysarthria, dysphagia, dysphonia and impaired movement of the tongue and facial muscles.
Caused by neurologic disorders like MS.
What is it called when there is endometrial stroma and glands in the myometrium of the uterus? How about outside the uterus?
In myometrium –> adenomyosis
Outside –> endometriosis
What is DNA laddering and what does it indicate?
DNA laddering is seeing 180bp segments of DNA on gel electrophoresis of cells. It indicates DNA is being broken up by endonucleases as part of karyorrhexis, and that the cells are undergoing apoptosis.
What does BLC2 do? Name a malignancy that commonly over expresses it.
BCL2 is an anti-apoptotic protein that helps the cell resist apoptosis. It is commonly overexpressed in follicular lymphoma due to the 14;18 translocation that is common.
Define pleiotropy
Pleiotropy = the occurrence of multiple, seemingly unrelated phenotypic manifestations, often in different organ systems, as a result of a single gene mutation.
It is important to recommend what daily activity to diabetic patients?
Foot inspection.
What translocation causes APML (see Auer rods on histo)
15;17
What is the function of IL-2 and what produces it?
Produced exclusively by antigen stimulated T lymphocytes. It stimulates growth and differentiation of T cells, B cells, NK cells and macrophages. Binding in an autocrine fashion stimulates clonal proliferation of the T cells.
What is the function of IL-1 and what produces it?
IL-1 is produced mainly by mononuclear phagocytes. It functions to activate lymphocytes and is associated w/ systemic illness changes like fever, anorexia, lethargy, etc.
______ is produced by activated macrophages and induces the systemic inflammatory response.
TNF-alpha.
______ are adhesion molecules that bind epithelial cells together within tissues.
Cadherins.
What sort of protein are fibronectins and laminins?
They are extracellular matrix glycoproteins that, through binding to integrins, facilitate cell binding to the extracellular matrix.
What causes molluscum contagiosum?
Poxvirus
Grossly, what do the lesions of molluscum contagiosum look like? Microscopically?
Flesh colored papules w/ central umbilication, commonly on the eyelids, face or trunk in children.
Microscopically see molluscum bodies which are eosinophilic viral inclusions.
What is the most important RF for endometritis?
Cesarean delivery is biggest one due to introduction of microbes and foreign bodies into the incised uterus.
What are some signs and sxs of post-partum endometritis?
Foul-smelling vaginal discharge, leukocytosis, fever and uterine tenderness.
How does nummular eczema present?
W/ coin-shaped, pruritic, erythematous patches.
Describe the coping mechanism of displacement?
Where feelings associated w/ one person or situation are inappropriately shifted to another.
The coping mechanism of _______ is where you attribute your thoughts or feelings to another person?
Projection
In the defense mechanism of _______, intense, unacceptable feelings are transformed into their opposites.
Reaction formation –> it is basically responding in a manner that is the opposite of one’s true feelings.
Ligand binding to the extracellular portion of a receptor tyrosine kinase causes what?
Dimerization of 2 identical receptor subunits.
A patient w/ headaches, chronic nasal discharge, atrophic nasal mucosa, and a perforated nasal septum increases your suspicion for what?
Habitual cocaine abuse.
Acutely after a heminephrectomy (removal of one kidney) the GFR is _____% from baseline. After about 6 weeks the GFR is ____% of baseline.
Initially –> 50%
6 weeks later –> 80%
What is the site of action of phosphodiesterase-5 inhibitors like sildenafil?
Vascular smooth muscle of the corpora cavernosa of the penis
Paralysis of the _______ results in an inability to raise the arm overhead and protrusion (“winging”) of the medial border of the scapula when the outstretched arm is pushed against resistance.
Serratus anterior
The ______ nerve innervates serratus anterior. The function of this muscle is to ______?
long thoracic nerve
stabilizes and rotates the scapula upward
What is the function of the levator scapulae? What innervates it?
It elevates the scapula and rotates the glenoid fossa inferiorly. Innervated by the 3rd and 4th cervical spinal nerves as well as the dorsal scapular nerve.
The trapezius ______ and ______ the scapula.
Elevates and retracts
Define schizophreniform disorder
Same sxs as schizophrenia that have been present for at least one month but no more than 6 months, and functional decline is not required whereas for schizophrenia it is.
What enzyme has a defect in acute intermittent porphyria?
Porphobilinogen deaminase. It catalyzes the step from porphobilinogen to hydroxymethylbilane.
What causes porphyria cutanea tarda?
uroporphyrinogen decarboxylase deficiency.
What tumor is myasthenia gravis associated with?
Thymoma
In addition to retinoblastoma, what is another malignancy that patients with familial retinoblastoma are at risk for?
Osteosarcoma
Absence of IgG (i.e. from hyper IgM syndrome where there is a CD40 defect) predisposes pts to what sorts of infections?
Infections w/ encapsulated pathogens.
In DKA, by how many mEq does the serum Na drop for every increase in 100 mg/dL of glucose?
1.6mEq
What is a dandy-walker malformation?
Aplasia or hypoplasia of the cerebellar vermis and cystic dilation of the 4th ventricle w/ enlargement of the posterior fossa.
What is syringobulbia?
A fluid filled cavity in the lower brainstem.
How do patients with complete androgen insensitivity syndrome present and what is the pathogenesis?
They will have minimal to no axillary or pubic hair, a vagina ending in a blind pouch w/ absence of uterus or upper vagina, and will have cryptorchid testes. Still get breast development.
There is an X-linked mutation to the androgen receptor such that it is insensitive to androgen.
What is the hallmark lab finding in 5alpha-reductase deficiency?
elevated testosterone:DHT ratio
Why are premature infants susceptible to interventricular hemorrhage?
Because the germinal matrix (located interventricularly) doesn’t start to involute until 28 weeks gestation and is absent by term. AND, the germinal matrix has a vascular network that is weak and lacks support such that it is more susceptible to hemorrhage.
The vast majority of the cancers in the head and next are _________?
Squamous cell carcinomas.
The chloride channel encoded by the CFTR gene, which is mutated in CF, promotes _______ of Cl at the respiratory epithelium and ______ of Cl at the sweat ducts?
Extrusion of Cl at respiratory epithelium.
Resorption of Cl at sweat ducts.
What is allelic heterogeneity?
It is where different mutations at the same genetic locus cause similar phenotypes.
What is epistasis?
Where the interaction between multiple genes comes together to produce a new phenotype or to modify/mask the effect of other genes?