uWorld 36 Flashcards
the RER is the site of synthesis of what
SECRETORY, LYSOSOMAL, an integral MEMBRANE proteins
post-translational medication before going to golgi
what is made in the SER
STEROID and PHOSPHOLIPID
also detoxifies numerous drugs (especially in hepatocytes)
all-steroid producing cells (cells in ADRENALS, GONADS, and LIVER) contain WELL-DEVELOPED SER
sarcoplasmic reticulum of striated muscle cells is a specialized SER
cells that have HIGHLY-DEVELOPED SMOOTH endoplasmic reticulum
STEROID PRODUCING CELLS:
ADRENALS (all cortex made things are cholesterol-derived steroid hormones)
GONADS
LIVER
when should one confront a terminally ill patient their denial stage of grief
if it is affecting their medical care (refusing treatment) or significant relationships
if this isn’t happening but they are in denial then encourage them to focus on short-term plans to maximize participation in areas that give meaning to their life
what cells are CD-19 positive
B cells
what does parvovirus B19 use to attach to human erythroid cells
erythrocyte P antigen (globoside)
what does EBV use to attach too CD21 (aka CR2)
gp350
CD21 is the cellular receptor for C3d complement component found on B cells and nasopharyngeal epithelial cells
acute onset dyspnea, hypoxemia, and hypocapnea are consistent with that
alveolar HYPERVENTILATION
assuming normal metabolic CO2 production, HYPOCAPNEA implies what
alveolar HYPERVENTILATION
EXAMPLE:
can be due to V/Q mismatch that causes DECREASED O2 and CO2 exchange (PNEUMONIA or PE)
-resultant hypoxemia triggers peripheral chemoreceptors and increases the respiratory drive above normal levels
-leads to excess CO2 excretion by the lungs, resulting in HYPOcapnea
-HYPOXEMIA PERSISTS b/c blood flowing through highly oxygenated lung cannot absorb extra O2 to compensate for the hypoxemic blood returning form the tissues
-TX is O2 and fixing underlying problem
upper airway obstruction, reduced ventilatory drive, respiratory muscle fatigue, and decreased chest wall compliance are all possible causes of what
HYPERcapnea and HYPOventilation
what acts as the central regulator of iron hemostasis
HEPCIDIN (acute phase reactant form liver)
↑ iron levels and inflammatory conditions → ↑ hepcidin synthesis
hypoxia and erythropoiesis → ↓ hepcidin synthesis
hepcidin interacts with FERROPORTIN (a transmembrane protein responsible for transferring intracellular iron to the circulation)
-upon binding hepcidin, ferroportin is internalized and degraded, ↓ intestinal iron absorption and inhibiting release of iron by macrophages
what brain tumors are collectively called gliomas and stain GFAP positive
astrocytomas
oligodendrogliomas
ependymomas
transposition of the great arteries is incompatible with life unless what is present
patent foramen ovale, septal defect, PATENT DUCTUS ARTEROSIS to allow for MIXING of the oxygenated blood with systemic blood
pts are tachypneic, cyanotic, and tachycardic
BLUNT AORTIC INJURY (traumatic aortic rupture) most commonly due to motor vehicle collisions occurs where
AORTIS ISTHMUS (tethered by the ligamentum arteriosum and is relatively fixed and immobile compared to the rest of aorta)
mechanism of injury involved SUDDEN DECELERATION that results in extreme stretching and torsional forces affecting the heart and aorta
most die before getting to hospital but may see chest pain, back pain, or shortness of breath w/ a WIDENED MEDIASTINUM on CXR
what are the symptoms of acute encephalitis and those specifically related to HSV encephalitis
HEADACHE, FEVER, MENTAL STATUS changes (lethargy, disorientation), CN deficits (Bells Palsy), SEIZURES
HSV Encephalitis:
temporal lobe damage- APHASIA and PERSONALITY CHANGES (hyper sexuality, aggression)
where is toxoplasma encephalitis usually found
RING-ENHANCING lesions of PARIETAL or FRONTAL loves
whats the difference b/w schizoid and avoidant personalities
schizoid ppl are content with being isolated
avoidant have the desire for social acceptance and may fantasize about having relationships
how does penicillin stop PBPs and how is this different than vanc
structurally similar to D-ala D-ala structure of peptidoglycan wall which facilitates their BINDING to PBPs
vanc DIRECTLY binds D-ALA D-ALA (this is an EARLIER STAGE of cell wall SYNTHESIS than penicillins)
how does PAH get into the blood
both freely filtered at the glomerulus but also SECRETED into the tubular fluid (an ENZYME-CARRIER MEDIATED process that can be SATURATED)
can excretion be maximalized?
no because excretion is filtration + secretion - reabsorption
filtration can never be saturated so neither can excretion
sharp mid-chest pain that increased with deep inspirations and decreased when sitting up
respiratory illness one week prior
normal bp and high pulse (120/70 and 110bpm)
nothing els tis given at all so what going on?
FRICTION RUB
chest pain of ACUTE PERICARDITIS is sharp and pleuritic in nature and characteristically decrease when patients SITS UP and LEANS FORWARD (decreasing pressure on the parietal pericardium)
during glycolysis ATP is generated when 1,3-BPG is converted to 3-phosphoglycerate by the enzyme phosphoglycerate kinase. what cells can bypass this step
ERYTHROCYTES can bypass this using BISPHOSPHOGLYCERATE MUTASE, an enzyme that converts 1,3-BPG to 2,3-BPG in a step that produces NO ATP
this is because 2,3-BPG is an important regulator of OXYGEN)HEMOGLOBIN BINDING
- conversion to 2,3-BPG is ↑ in states of HYPOXIA or chronic ANEMIA
- 2,3-BPG allosterically decreases hemoglobins affinity for oxygen
what is an interscalene nerve block
regional anesthesia technique used for procedures involving the shoulder and upper arm
anesthetic is administered in the SCALENE TRIANGLE (b/w middle and anterior scalene muscles in the posterior neck) and affects the BRACHIAL PLEXUS TURNK and ROOTS
transient ipsilateral DIAPHRAGMATIC PARALYSIS in nearly all pts by anesthetizing the roots of the PHRENIC NERVE (C3-C5)
what its the omohyoid msucle
originates form upper scapular border and travels along the front of the neck to insert into the hyoid bone
innervated by cervial plexus (ansa cervicalis) originating form C1-C3
the risk of cardiovascular events with oral contraceptive pills in increased in whom
SMOKERS OVER 35
APC, BRCA1, KRAS, RB, TP53
which ones are tumor suppressors which ones are oncogenes
oncogenes: KRAS
tumor suppressors: APC, BRCA1, RB, TP53
name all the proto-oncogenes and their cancers in uWorld
ABL: CML, ALL
BRAF: melanoma
HER1: squamous cell lung cancer
HER2 breast/ovarian cancer
RAS: lung, colon, pancreatic (KRAS), renal cell, bladder (HRAS)
SIS: astrocytoma, osteosarcoma
TGFA: astrocytoma, hepatocellular carcinoma
name all the tumor suppressors and their cancers in uWorld chart
APC/beta-catenin: stomach, colon, pancreatic, FAP
BRCA1/BRCA2: breast/ovarian
DCC: colon cancer
NF1: neuroblastoma, NF1, sarcoma
RB: retinoblastoma, osteosarcoma, other cancers
TP53: most cancer, Li-Fraumeni
VHL: VHL, renal cell
WT1: wilms tumor
a patient with pain/distention, bloody diarrhea, fever, and signs of shock in the setting of untreated ulcerative colitis probably has what
TOXIC MEGACOLON
get a PLAIN ABDOMINAL X-RAY
barium enema and colonoscopy are contraindicated as it may cause perforation
(fun fact: toxic megacolon is also associated with c.diff)
AQUAGENIC PRURITUS, FACIAL PLETHORA and SPLENOMEGALY w/ elevated hemoglobin, hematocrit, and leukocytes suggests what
POLYCYTHEMIA VERA
JAK2 (CYTOPLASMIC TYROSINE KINASE) mutation causing constitutive activation of the kinase domain
what conditions are associated with polycythemia vera
peptic ulcer disease (altered mucosal blood flow due to increased viscosity)
gouty arthritis (higher red cell turnover)
what binds to receptor tyrosine kinases
insulin
insulin-like growth factor
epidermal growth factor
what causes decreased hemoglobin and haptoglobin levels as well as increases serum lactate dehydrogenase and unconjugated bilirubin
HEMOLYTIC ANEMIA
chronic hemolysis can lead to what in the kidney
breakdown of iron-containing erythrocytes that leas to IRON DEPOSITION in the kidney (HEMOSIDEROSIS) which can interfere with proximal tubule function and can cause interstitial scaring and cortical infarcts
hemosiderosis colinde with microvascular thrombosis an increase risk of chronic kidney disease
interstitial nephritis is common with what
drugs (analgesics, antibiotics)
recent infection
systemic condito (sarcoidosis)
membranous glomerulonephropathy is associated with what
SLE
drugs (NSAIDs)
hep B and C
solid tumor malignancies (lung, prostate, GI)
cast nephropathy is usually see with what
multiple myeloma
how does polymyxin work
binds to, disrupts, and interferes with permeability of the cytoplasmic membrane
how is resistance to aminoglycosides obtained
amino glycoside modifying enzymes
largely plasmid encoded and sere to phosphorylate, adenylate, or acetylate the antibiotic molecules and thus lead to decreased binding ability to ribosomal units
pseudomonas can also decrease antibiotic entry into the bacterium
what is the germ tube test and what is it for
CANDIDA
blood cultures inoculated for 3 hours at 37C shows formation of TRUE HYPHAE form of yeast called “GERM TUBES”
