uWorld 55 Flashcards
what do C3a and C5a do
both are anaphlatoxins (so is C4a)
C3a: recruits and activates EOSINOPHILS and BASOPHILS
C5a: recruits and activates NEUTROPHILS
what are specific neutrophil chemotactic agents
N-FORMYlATED PEPTIDES
leukotrienes B4
5-HETE (the leukotriene precursor)
C5a
what is NEPRILYSIN
a metalloproteiase that cleaves and inactivates endogenous peptides including NATRIURETIC PEPTIDES, GLUCAGON, OXYTOCIN, and BRADYKININ
inhibition of neprilysin leads to increased levels of ENDOGENOUS NATRIURETIC PEPTIDES, which promote beneficial effects in heart failure
how do you treat and adrenal crisis
hydroxycortisone or dexamethasone
HIGH-FLOW IV FLUIDS
aflatoxins cause what mutation
G:C to T:A mutation in codon 249 of the p53 gene leading to hepatocellular carcinoma
what do short non-coding RNA sequence (microRNA and small interfering RNA) do
induce post translational gene silencing by base-pairing with complementary sequences within target mRNA molecules
a double stranded RNA molecule that is complementary to a region of mRNA fucks up what
mRNA translation (posttranscriptional modification)
what is RNA interference
an important mechanism in which short (20-30bp) non-coding RNA sequence induce POSTTRANSCRIPTIONAL GENE SILENCING
types of silencing RNA include SMALL INTERFERING RNA (siRNA) and microRNA (miRNA)
after being transcribed, miRNA undergoes processing in the nucleus to form a DOUBLE-STRANDED precursor that is then exported into the cytoplasm
there, the precursor is clever into a short RNA helix by a ribonuclease protein called DICER
individual strands are then separated and incorporated into RNA-INDUCED SILENCING COMPLEX (RISC)
multi protein complex uses its associated miRNA was a template to bind to complementary sequences found on target mRNAs
exact match results in mRNA degradation, but a partial match also causes translational repression by preventing ribosome and transcription factor binding
whats the difference b/w brown and black pigment stones (gallbladder)
BLACK stones: CHRONIC HEMOLYSIS (sickle cell, spherocytosis) or increased ENTEROHEPATIC CYCLING of bilirubin (ILEAL disease)
BROWN stones: BILIARY TRACT INFECTION (E coli, liver fluke) which release of microbial beta-glucronidases
BOTH result in increased UNCONJUGATED BILIRUBIN leading to calcium-bilirubinate precipitation
what do the gluteus medius and minus do
stabilize hip
abduct the thigh when limb is extended
whats the obturator internus do
fan-shaped muscle originating from the medial surface of the obturator membrane, ischium, and pubic rim
exits pelvis through he lesser sciatic foramen and insets on the greater trochanter of the femur
externally rotate thigh when extended and abduct the thigh when flexed (same as piriformis)
what does the piriformis do
originates on anterior aspect of sacrum and occupies most of the space in the greater sciatic foramen
inserts on the greater trochanter of the femur
externally rates the thigh when etude and abduct the thigh when flexed
what structures run above the piriformis and under it in the greater sciatic foramen
above: SUPERIOR gluteal vessels and superior gluteal nerve
below: INFERIOR gluteal vessels, internal pudendal vessels, multiple nerves (SCIATIC)
what is piriformis syndrome
muscle injury or hypertrophy compression SCIATIC nerve to cause sciatica-lied symptoms (pain, tingling, and numbness in buttocks and along the nerve distribution)
muscle can be tender with deep palpation or on stretching with adduction and internal rotation
conditions that cause GI irritation (infection, chemo, distention) causing EMESIS should be treated how
5-HT3 receptor antagonists (ondansetron)
the GI irritation results in increased mucosal SEROTONIN relate and activation of 5-HT3 receptor on vagal and spinal afferent nerves
what is pharyngoconjucntival fever
ACUTE onset FEVER, COUGH, CONGESTION, PHARYNGITIS, and OCNJUCTIVITIS
ADENOVIRUS
dsDNA virus (NAKED)
localized back pain, low-grade fever, recent staph bacteremia suggests what
VERTEBRAL OSTEOMYLITIS
hematogenous spread (skin or soft tissues, IV cath), direct invasions form trauma or local spinal procedures, or direct spread from adjacent soft tissue infection
BLOOD CULTURES and MRI of SPINE
what causes digital clubbing
prolonged hypoxia
lung cancer, TB, cystic fibrosis, suppurative lung disease (emphysema, bronchiectasis, and chronic lung abscesses)
cyanotic congenital heart disease (5Ts- especially tetralogy of fallot) and bacterial endocarditis
IBD, hyperthyroidism, and malabsorption
what does an S3 heart sound in an adult suggest
suggests VENTRICULAR ENLARGEMENT
chronic severe mitral regurg, chronic aortic regurg, heart failure associated with dilated or ischemic cardiomyopathy
heard during DIASTOLE, shortly after S2
heard with bell at APEX while patient is in the left lateral ducbitous position at END EXPIRATION
what does amyl nitrite inhalation do
causes VASODILATION, decrease in venous return and blood pressure
decreases intensity of S3 (so does furosemide and valsalva)
lower extremity cyanosis and clubbing in a 10 year old WITHOUT pulse difference in extremities suggests what
PATENT DUCTUS ARTERIOSUS complicated by Eisenmenger syndrome
(coarctation has pulse differences in upper and lower body)
what kind of hypersensitivities are seen in SLE
Type II: antibodies against blood cells (PANCYTOPENIA)
Type III: LUPUS NEPHRITIS- immune complex deposition causing PROTEINURIA and RBC CASTS
what does primaquine do in malaria treatment
kills HYPNOZOITES (the LATENT HEPATIC infection) that are caused by P VIVAX and OVALE
what is the most serious long term effect of chloroquine use
RETINOPATHY
how do you manage someone with somatic symptoms disorder
schedule REGULAR VISITS with SAME PROVIDER
LIMIT UNNECESSARY WORKUPS and REFERRALS to specialists
reassure that serious illness has been ruled out
legitimize symptoms but make functional improvement to treatment goal
- decrease stress
- improve coping strategies
mental health referral only once physician-patient relationship is well established
patients with sickle cell (or other hemolytic anemias) are predisposed to what kind of anemia
FOLIC ACID DEFICIENCY b/c of large TURNOVER of ERYTHROCYTES
how can one tell if microcytic anemia in sickle cell (or another hemolytic anemia) is due to extra medullary hematopoiesis or folic acid deficiency
check the RETICULOCYTE INDEX
LOW reticulocyte index suggests erythropoiesis is NOT the main factor contributing to the microcytic anemia
elevated RI relents adequate marrow response and would suggest erythropoiesis
non-pupil sparing 3rd nerve palsy is due to compression where
POSTERIOR CEREBRAL ARTERY (ISPSILATERALLY)
nerve passes between PCA and superior cerebellar artery(found right below the PCA on imaging)- either one can compress it
chronic smoking or poorly controlled HTN are risk factors for aneurysmal anywhere intracranially
infant with delated motor development and flaccid paralysis (hypotonia, decreased deep tendon reflexes)- can’t life up head or roll over at 6 months- likely has what
SPINAL MUSCLAR ATROPHY
surveil motor neuron (SMN1) gene mutation that encodes for snRNPs in lower motor neurons- impaired SPLICEOSOME FUNCTION and DEGENERATION of ANTERIOR HRONS CELLS
what muscles abudct the hip
gluteus medius
gluteus minimus
what muscles extend the hip
gluteus maximus
semitendinosuss
semimembranososi
biceps femoris-long head (originates from ischial tuberosity and inserts onto lateral head of the fibula)- also flexes let
what muscles flex the hip
iliopsoas
rectus femoris
tensor facia lata
what does obturator externus do
lateral rotator of thigh
arises form anteriolmeidal surface of the obrutaor foramen and inserts near the greater trochanter of the femur
what is the vests medialis
KNEE EXTENSOR
part of quadriceps femurs
raises form proximal femur and inserts into tibial tuberosity via PATELLA
corticosteroids are immunosuppressants- what immune cells are elevated from chronic corticosteroid use
NEUTROPHILS- they fuck up the sticking of the marginal pool thus increasing the numbers but they are not functional
(increase risk of infection)
what are the CNS and respiratory side effects of corticosteroids
CNS: HYPOMANIA, PSYCHOSIS, sleep disturbances
respiratory: INCREASE SURFACTANT production
what are the endocrine and GI side effects of corticosteroids
endocrine: HPA axis suppression, HYPERGLYCEMIA, HYPOGONADISM, OSTEOPOROSIS (decrease bone formation and calcium and phosphate absorption)
GI: peptic ulcer, GI bleed (decreased prostaglandins)
what are the skin side effects of coticosteorid
central obesity, buffalo hump
skin ATROPHY, bruisability (decreased collagen and fibroblasts)
proximal muscle weakness
whats the order of most common vessels for atherosclerosis
- Abdominal Aorta
- coronary arteiras
- popliteal
- internal carotid
- circle of willis
what is characterized by low lying cerebellar tonsils that extend below the foramen magnum into the vertebral colum
CHIARI TYPE I malformation (most common and benign)
presents during adolescence/adulthood with PAROXYSMAL OCCIPITAL HEADACHES (due to meningeal irritation) or CEREBELLAR DYSFUNCTION (dizziness, ataxia) due to compression of cerebellar tonsils
what is seen in CHIARI TYPE II malformation
evident in neonatal period
downward displacement of cerebellum (vermis, tonsils) and medulla through foramen magnum
non-communicating hydrocephalus almost always occurs due to AQUEDUCTAL STENOSIS
compression of medulla may cause dysphasia, stridor, apnea
associated LUMBAR MYELOMENINGOCELE- can cause lower limb paralyisis
what is BLEPHAROSPASM
2nd most common FOCAL DYSTONIA
involuntary forcible closure of the eyelids
initial symptom is uncontorllbzlby blinking
the hiccups are an example of what
MYOCLONUS (sudden brief, sometimes severe (shock-like) muscle contraction
pathological myoclonus is seen in what
epilepsy
CRUTZFIELD-JAKOB
what causes characteristic brawny discoloration of varicose veins and what does resulting tissue ischemia cause
extraversion of RBCs into the tissues leading to IRON deposition
resulting tissue ischemia causes VENOSU STASIS DERMATITIS- associated with POOR WOUND HEALING
what is seen in lymphedema
soft and pitting edema first
eventually becomes firm and non pitting due to progressive fibrosis and thickening of overlying skin
what is beau d’orange
erythematous, ITCHY breast rash with SKIN TEXTURE CHANGES analogous to an orange peel
key dermatologic presentation of INFLAMMATORY BREAST CANCER and is caused by cancerous cells OBSTRUCTING LYMPHATIC DRAINAGE due to spread to the dermal lymphatic spaces
what are the key feature os invasive beast cancers
ductal: most common type, nest and chords of cells
lobular: small cells in single file, mammary stoma invasions
inflammatory: peau d’ orange, dermal lymphatic invasion
