test #22 4.12 Flashcards
signs of hypothyroidism
fatigue, weight gain, constipation, SLOWED RELAXATION of deep tendon reflexes, dry coarse skin
most sensitive marker for diagnosis of hypothyroidism
serum TSH
(though, will not be elevated in patients w/ hypothyroidism due to TSH deficiency [central hypothyroidism]
valproate teratogeniticty
neural tube defects (1-3% risk)
valproate inhibits intestinal folic acid absorption
signs of duodenal atresia?
clinical hallmark: bilious vomiting w/o abdominal distension. usually noted on 1st day of life.
peristaltic waves may be visualized in abdomen & history of polyhydramnios due to failure of amniotic fluid reabsorption in distal instestine
often seen in down syndrome
death resulting from bilateral renal agenesis
death from pulmonary hypoplasia shortly after birth
ebstein’s anomaly? cause?
atrialized right ventricle (downward displacement of tricuspid valve).
occurs when mom takes lithium early in pregnancy.
anaphylactic reaction to type O blood products in person w/ recurrent sinopulmonary and GI tract infections?
selective IgA deficiency.
anaphylaxis to IgA! make IgG against it. IgA = foreign
C1 esterase inhibitor deficiency
hereditary angioedema. rare. AUTOSOMAL DOMINANT. ace inhibitors are contraindicated.
C1 esterase inhibits nonspecific C1 fixation
delirium? causes?
delirium: ‘waxing & waning’ fluctuations in consciousness. acute, global memory impairment, visual hallucinations. ‘altered sensorIUM’
reversible & commonly occurs in hospital setting
AEIOU TIPS:
alcohol, electrolyte imbalace, iatrogenic (i.e. meds), oxygen hypoxia, uremia. trauma, infxn, posion, seizure (post-ictal)
delirium vs. dementia
onset, consciousness, course, prognosis, memory
in delirium:
acute, impaired consciousness, fluctuating symptoms, reversible, GLOBAL memory loss.
in dementia:
gradual, intact consciousness, progressive decline, usu irreversible, remote memory SPARED.
(reversible, at least partially, with: NPH, vitamin b12 deficiency, hypothyroidism, neurosyphilis, HIV)
Reye’s syndrome description and pathogenesis
hepatic failure and acute encephalopathy. associated w/ use of aspirin in patients 5-14 y/o.
pathogenesis: unknown; affected children have metabolic error sensitizing to toxic effect of salicylates. especially in virally-infected cells. causes mitochondrial dysfunction.
mechanism: aspirin metabolites decrease beta-oxidation by reversible inhibition of mitochondrial enzymes.
describe lab findings & histology in reye’s
vomiting, hepatomegaly. jaundice = rare.
increased ALT, AST, ammonia, bilirubin, prolonged PT and PTT.
light microscope: microvesicular steatosis. NO necrosis or inflammation.
EM: swelling, decreased mitochondria, glycogen depletion.
do not give aspirin (salicylates) to kids under..
16 y/o (except if Kawasaki)
histology of viral hepatitis
apoptosis of hepatocytes, acinar necrosis, periportal mononuclear inflammatory infiltration
liver findings in patients w/ right-sided heart failure
centrilobular congestion
histology of primary biliary cirrhosis
bile duct destruction, periductal granulomatous inflammation, bile duct proliferation
respiratory epithelium with stratified squamous epithlium
response to chronic irritation: METAPLASIA.
adaptive: resistant to irritation than columnar cells.
HOWEVER: no cilia/goblet cells: no mucociliary clearance. can lead to dysplasia (low-grade atypical cells). risk factor for carcinoma (high-grade atypia).
REVERSIBLE, can resolve upon discontinuation of smoking.
renal response to markedly narrowed renal artery (i.e. stenosis)
compensatory RENIN secretion (juxtaglomerular apparatus)
eventually: juxtaglomerular apparatus undergoes hypertrophy & hyperplasia (to make more renin).
juxtaglomerular apparatus: JG cells and macula densa
juxtaglomerular cells: modified SMOOTH MUSCLE CELLS located in alls of afferent and efferent arterioles.
macula densa: tall, narrow cells in distal tubules. monitor osmolarity and volume of urine that passes into distal tubules. pass info to JG.
juxtaglomerular apparatus (2)
juxtaglomerular cells: modified smooth muscle cells in afferent & efferent arteriole. secrete RENIN.
macula densa: tall narrow cells in distal tubules, sense osmolarity & volume in tubules
noise-induced hearing loss?
trauma to sterociliated hair cells of organ of orti. >85dB. distortion / fracture of stereocilia due to shearing forces against tectorial membrane.
loose high frequency first (4000Hz)
frequency of speech
500-3000Hz
acoustic reflex?
dampens effects of prolonged loud noise by contracting stapedius & tensor tympani.
tensor tympani & stapedius
note. paralysis of mandibular CNV3 results in hypoacussis – complete loss of tensor tympani tone = hard to hear (even though it normal fxn dampens sounds at other extreme).
loss of stapedius (CNVII) = hyPERacussis
cupula
lies at apex of cochlea. has cells that sense rotation.