uWorld 1 Flashcards
what are club (aka clara) cells and what are their role
nonciliated, secretory constituents of the terminal respiratory epithelium
secrete club cell secretory protein and surfactant components
help detoxify inhaled substances via CYP450 mechanism
what cells are responsible for the findings in centriacinar emphysema
neutrophils and macrophages release PROTEASES (elastase, cathespins, MMPs) that degrade the eco and also generate free oxygen radicals that impair the function of protease inhibitors (A1AT)
weight loss, mucosal pallor, hepatomegaly, and massive splenomegaly
gain-of-function mutation of non-receptor tyrosine kinase protein in hematopoietic cells, leading to persistent activation of signal transducers and activators of transcription (STAT) proteins
JAK 2 mutation
primary myelofibrosis
teardrop cells (dacrocytes) on peripheral smear
what is ruxolitinib
JAK2 inhibitor
approved for treatment of primary myelofibrosis
hydrocele results from what
incomplete obliteration of the PROCESSUS VAGINALIS (a projection of the peritoneal cavity that accompanies the descendant testis into the scrotum and ultimately toms the TUNICA VAGINALIS of the testis)
what causes a bifid scrotum
malunion of labioscrotal folds (forms labia majora in females)
what is the most common cause of CF
3-bp deletion that removes phenylalanine at deltaF508
impaired post translational modification in the endoplasmic reticulum (goes to proteasome and no CFTR on the cell surface at all)
what kind of CF is seen in Ashkenazi jews
mutations causing premature termination of the transmembrane protein (nonsense, frameshift) also lead to a complete absence of membrane-bound CFTR
mild CF disease is usually do to what
mutations impairing chloride iron conduction through CFTR or those causing decreased production of functionally normal CFTR (reduced mRNA or protein stability)
what organism is gamma-hemolytic (no hemolysis) catalase-negative, can grow in presence of bile, but cannot grow in 6.5 NaCl
S. bovis
enterococci are the same except they can grow in 6.5NaCl
what organisms are PYR (pyrrolidonyl arylamidase) positive
Strep progenies
enterococci
what biochemical processes occur exclusively in the mitochondria
beta-oxidation of fatty acids ketogenesis citric acid cycle parts of urea cycle (carbamoyl phosphate synthetase 1 and ornithine transcarbamoylase) pyruvate carboxylation
where does the pentose phosphate shunt occur
cytoplasm
transketolase is an enzyme of this pathway (B1 is a cofactor)
what does pyruvate carboxylase do and where is it found in the cell
catalyzes the initial step in gluconeogeneissi by converting pyruvate to oxaloacetate (B7 is cofactor)
mitochondria
what does ornithine transcarbomoylase do and where is it found in the cell
catalyzes the second step of the urea cycle where ornithine and carbamoyl phosphate are combined to form citrulline
mitochondria
deficiency leads to hyperammonemia and mental retardation
what does succinate dehydrogenase do and where is it found in the cell
enzyme of TCA cycle that converts succinate fumarate
FAD+ to FAD2 happens here
inner mitochondrial membrane
what does HMG CoA Lyase do and where is it found in the cell
mitochondrial enzyme that is responsible for ketogenesis from HMG CoA
what is reaction formation
defense mechanism in which an individual TRANSFORMS UNACCEPTABLE FEELINGS or impulses into their EXTREME OPPOSITES
immature defense mechanism
what is displacement
transfer of feelings or impulses toward a safer, more acceptable object
immature defense mechanism
what is projection
involves attributing unacceptable impulses or behavior onto another person or situation
immature defense mechanism
what is rationalization
individual makes excuses for unacceptable feelings or behavior
immature defense mechanism
what segment of the nephron responds to vasopressin by increasing absorption of a specific solute that is important for generating high medullary concentration gradient
medullary segment of the collecting duct
what is the greatest risk that occurs from a cavernous hemangioma in the brain and where are they found
intracerebral hemorrhage
most commonly found in the brain parenchyma above the cerebellar tentorium
pts often have seizures
lesions have tendency to bleed (irregular hyperdense/bright mass on head CT)
what is the defect in xeroderma pigmentosa
endonuclease
what does the presence of an S3 indicate in older individuals (its normal in the young) and what is causing the sound
left ventricular failure
sound is from:
- forceful, rapid filling of a ventricle that has normal or elevated compliance
- normal or even decreased filling rates when ventricular compliance is low
- blood flowing into an overfilled ventricle with high end-systolic volume
what is the cause of pulsus paradoxus in cardiac tamponade
bulging of intraventricular septum when accumulation of large quantities of pericardial fluid prevents the expansion of the ventricular free walls
during inspiration, venous blood return increases and the intraventricular bulges into the left ventricle to allow the right ventricle to accommodate the increased blood volume-
resultant decrease in left ventricular filing produces pulsus paradoxus
what type of obstruction is seen in hypertrophic cardiomyopathy and what kind of heart murmur is it associated with
dynamic left ventricular outflow obstruction
mitral regurgitation
what is coopers ligament
aka pectineal ligament- thickened peace of pectineal facia
overlies the pectineal ridge of the pubic bone and is located posteriorly to the femoral canal
what forms the posterior wall of the inguinal canal
transversals facia
what is an opening in the transversals facia and is the site of protrusion of indirect inguinal hernias
deep inguinal ring
what is the female equivalent of the spermatic cord
round ligament
leaves though the deep inguinal ring and passes through the inguinal canal
what are the adverse effects of methotrexate
oral and GI ulceration hair follicle tox (alopecia) bone marrow tox (pancytopenia) hepatotoxicity (hepatitis, fibrosis, cirrhosis) pulmonary fibrosis
what areas of the GI tract are exposed to the most gliadin and thus should be biopsied
duodenum
jejunum
see villus atrophy/flattening and lymphocyte infiltration of the intraepithelial cells
what is used to diagnose lactose intolerance
hydrogen breath test (malabsorbed lactose is fermented by bacteria, thereby increasing the amount of hydrogen exhaled and confirming a diagnosis)
gastric bands must pass through what structure in order to encircle the stomach
lesser omentum
what is a gastric band
inflatable silicone device placed around the gastric cardia
it is intended to slow the passage of food, increasing satiety and limiting the amount of food consumed
what is the lesser omentum and what ligaments make it up
double layer of peritoneum that extends from the liver to the lesser curvature of the stomach and the beginning of the duodenum
hepatogastric ligament
hepatoduodenal ligament
what is found between the two layers of the lesser omentum, close to the right-sided free margin
hepatic artery common bile duct portal vein lymphatics hepatic plexus
what is found b/w the two layers of the lesser omentum, near where the lesser omentum attaches to the stomach
right and left gastric arteries
gastric veins
what is another name for the round ligament of the liver and what structure is it found in
aka ligamentum hepates teres (remnant of fetal umbilical vein)
contained in the falciform ligament
what is the greater omentum
large fold of visceral peritoneum that extends from the greater curvature of the stomach, travels inferiorly over the small intestine, and then reflects on itself and ascends to encompass the transverse colon before reaching the posterior abdominal wall
what is the gastrocolic ligament
section of the greater omentum that stretches form the greater curvature of the stomach to the transverse colon
forms part of the anterior wall of the lesser sac and is often divided during surgery to provide access to the anterior pancreas and posterior wall of stomach
what is the splenorenal ligament derived from and what does it contain
derived form peritoneum and lies between left kidney and spleen
contains the splenic vessels and the rail of the pancreas
what is the key metabolic difference of methotrexate and 5-FU
methotrexate prevents the reduction of folic acid to THF
5-FU binds THF and thymidylate synthetase in the stable-reaction intermediate form
what are the functions of cytarabine and gemcitabine
pyrimidine analog antimetabolites that get incorporated into DNA leading to strand termination
gemcitabine is not S-phase specific (and inbitis ribonucleotide reductase) and cytarabine is
what is fludarabine
a deamination-resistant purine nucleotide analog that exerts its cytotoxicity by many mechanisms, including inbhition of DNA polymerase,e DNA primate, DNA ligase, and ribonucelotide reductase
use to treat CLL
