test #23 4.12 Flashcards
congenital lactase deficiency
rare autosomal recessive. caused by gene near (but separate from) lactase gene
bacterial fermentation of undigested lactose leads to..
fermentation, producting short-chain fatty acids and excess hydrogen —> acidic stool
stool osmotic gap
most stool osmolality –> Na and K. gap = colonic fermentation products.
when mostly electrolytes, osmotic gap low (< 50mOsm/kg).
when poorly absorbable substances present, osmotic gap large > 100mOsm/Kg
D-xylose absorption test
absorption of D-xylose diminished in numerous malabsorptive conditions. like celiac sprue. not associated w/ lactose intolerance.
D-xylose, a monosaccharide that does not require digestion for absorption; just needs an intact mucosa.
can distinguish between musocal & nonmucosal causes of malabsorption (i.e. celiac vs. pancreatic insufficiency)
lactose deficiency individuals have… (3)
increased stool osmotic gap, increased breath hydrogen content, and decreased stool pH upon lactose challenge.
pancreatic location in abdomen
head, neck, body retroperitoneal. tail is intraperitoneal.
head overlies L2. body overlies L1 and L2. posteriorly contacts aorta, superior mesenteric vessels, left kidney. tail courses w/ splenorenal ligament alongside splenic vessels
anthax most commonly acquired via
exposure to infected animals / animal products OR use as a biological weapon
forms of anthrax (3)
(1) cutaneous, most common
(2) pulmonary, 5% (but nearly 100% mortality)
(3) gastrointestinal, rare
ERB-B2 gene aka.. expressed in..
overexpressed in breast cancer, adenocarcinoma of ovary, stomach, lung, salivary glands.
codes for transmembrane glycoprotein w/ tyrosine kinase activity.
normally expressed in small amounts.
n-myc associated with..
neuroblastoma and small cell carinoma of lung
sis proto-oncogene codes for.. overexpressed in?
platelet-derived growth factor. overexpressed in astrocytoma and osteosarcomas
rx for cryptococcus meningitis
amphotericin B + flucytosine. long-term maintenance w/ fluconazole
schizoid vs. avoidant
avoidant strongly desires acceptance. schizoid do not care.
avoidant: inadequacy, timidity, fear of rejection
diffuse esophageal spasms
periodic, non-peristaltic contractions of esophagus.
usu painful. “cork-screw” on barium esophogram.
intermittent dysphagia w/ occasional chest pain. can mimic UNSTABLE ANGINA. rule out w/ complete cardiac work-up
symptom of GERD
heartburn: burning, central pain frequently after meal or night. DES = crampy, not burn
digital rectal exam of BPH vs. prostate cancer.
cancer: nodular & firm
changes resulting from BPH upstream
bladder wall hypertrophies: increase contractile force.
ureter, pelvis, calyces dilate (hydronephrosis)
renal parenchyma atrophic and scarred due to reflux of urine & damage.
3rd pharyngeal puch
inferior parathyroid glands & thymus
1, 2, 3, 4
ears, tonsils, bottom to, top
ears, palatine tonsils, inferior parathyroid & thymus, superior parathyroid & ultimobranchial body
thyroid diverticulum from
floor of the foregut
laryngeal cartilage originates from
4th and 6th pharyngeal arches
mutation in polycythemia vera
clonal myeloproliferative disease of pluripotent hematopoietic stem cells. 95% have V617F mutation involving JAK2 gene.
replaces a valine w/ phenylalanine at 617 –> makes hematopoetic cells more sensitive to growth factors (like EPO and TPO)
EPO producing tumors
hepatocellular carcinoma, renal cell carcinoma
shigellosis can be caused by..
shigella dysenteriae, flexneri, boydii, sonnei.
80% are sonnei in US
shigella entry into body
M cells in peyer’s patches in mucosa of ileum
substrates in urea cycle
ordinarily, careless crappers are also frivolous at urination
in mito: ornithine + carbamoyl, citrulline,
in cytosol: aspartate, arginosuccinate, fumarate, arginine, urea (and regenerate ornithine)
N acetylglutamate is needed for
activity of carbamoyl synthetase II. to convert NH3 + CO2 + ATP —> carbamoyl phosphate
myasthenia gravis particularly affects
waxing & waning progressive weakness of voluntary muscles, particularly those innervated by motor nuclei of brainstem (ocular, masticatory, facial, deglutitional (swallowing), and lingual movement)
what happens when anti-nAChR binds in myasthenia gravis?
receptor internalization & complement fixation (degradation).
less opening of nicotinic cation channels –> reduced end plate potential
classic presentation of multiple sclerosis
- scanning speech, internuclear opthalmoplegia, intention tremor, incontinence, nystagmus
eye findings w/ multiple sclerosis
optic neuritis: sudden loss of vision resulting in Marcus Gunn pupil. internuclear opthalmoplegia.
selective muscarinic antagonist for abdominal cramping, nausea, sweating, diarrhea
scopolamine and hyoscyamine
which symptoms may persist in wernicke-Korsakoff?
memory loss (korsakoff syndrome). can persist after fixing oculomotor dysfunction & ataxia in Wernicke-Korsakoff
which brain regions are damaged in korsakoff syndrome?
anterior & dorsomedial thalamic nuclei – leads to memory loss and confabulation. when unsure of fact, fill in memory gap with fabricated story they believe to be true.
presentation of wernicke-korsakoff (3)
thiamine deficiency leads to impaired neuronal energy utilization –> cell death & atrophy
- oculomotor dysfxn: damage to CN III CN VI, and vestibular nuclei. rapidly reversible w/ thiamine
- ataxia: cerebellar cortex & vestibular nuclei damage. takes longer to resolve, can be permanent
- mental status change: disorientation, apathy, decreased attn respond well. memory & learning abnormalities often persist –> korsakoff syndrome (mamillary body)