Set 7 Flashcards
A patient comes to your clinic because he has not been able to extend his wrist for the last 3 days. Upon further questioning, you discover that 4 days ago the patient passed out drunk for an entire night while his arm was draped over a chair. What is this patient’s condition? (FA14 p414) (FA15 p418) (SU15 p238) Does the regeneration of neurons occur in both the CNS and the PNS? What is the rate of growth of a new axon in the PNS?
Saturday night palsy/radial nerve (C5-T1) neuropathy - can occur with midshaft fracture of humerus or compression of the axilla (crutches or sleeping with arm over chair)
Regeneration of nerves occurs only in the PNS (White matter (myelinated) is the key to this: in teh PNS Schwann cells are responsible for myelination and secrete a chemotrophic growth factor that helps axonal regeneration. Oligodendrocytes in the CNS secrete a chemical that inhibits axonal growth)
Rate of growth of a new axon in the PNS is 1-2 mm per day
Women with polycystic ovarian syndrome can have decreased levels of sex hormone-binding globulin (SHBG), which contributes to the development of hirsutism. What can an elevated SHBG produce in men? What is the general mechanism of action of the steroid/thyroid hormones? (FA14 p316, 581) (FA15 p321-322, 585)
Increased SHBP -> lowers free testosterone -> gynecomastia
SHBP is a transport protein that binds estradiol and testosterone and carries them in the blood
General mechanism: work inside the nucleus and affect gene expression (slower)
What is the equation for determining a drug’s volume of distribution? What types of disease would alter the volume of distribution of a highly protein-bound drug such as ceftriaxone? (FA14 p239) (FA15 p243)
Volume of distribution = amount of drug in the body/plasma drug concentration
Liver disease
Decreased binding proteins (synthesized in the liver)
Increased free drug distributes in tissues
Decreased plasma concentration
Renal disease
Plasma protein binding of many drugs is impaired
Larger apparent volume of distribution
A 36-year-old malnourished woman comes to the ER with abdominal pain. She has a fever, abdominal tenderness (without rebound tenderness), and anorexia. Her WBC count is markedly elevated, and her RDW is high. The patient reports having had a bowel movement this morning and is not nauseated. A small bowel follow-through reveals “skip” lesions (discontinuous areas of focal narrowing) and a “string” sign (significant narrowing) in the terminal ileum. What disease does this patient likely have? What drugs can be used to treat it? (FA14 p354) (FA15 p362)
Crohn disease: skip lesions and string sign, transmural inflammation of of bowel wall and cobblestone appearance of mucosa
Treatment: 5-ASA, corticosteroids, azathioprine, 6-mercaptopurine, methotrexate, infliximab or adalimumab (TNF alpa monoclonal antibodies)
A 30-year-old man begins to develop shortness of breath and cyanosis even at rest. Exam reveals clubbing and a systolic murmur. He mentions that he has had a murmur since childhood. Further work- up reveals a large ventricular septal defect and pulmonary hypertension. The patient is diagnosed with Eisenmenger syndrome. Describe how this syndrome develops. (FA14 p283) (FA15 p289)
Uncorrected L to R shunt (VSD, ASD, PDA) -> increased pulmonary blood flow -> pathologic remodeling of vasculature -> pulmonary arteriolar HTN. RVH occurs to compensate -> shunt becomes R to L [FLOW REVERSAL] (both RH pressure and pulmonary pressures are higher than left side)
Causes cyanosis, clubbing, and polycythemia
The parents of a 5-year-old girl are concerned because their daughter has night terrors, sleepwalking, and enuresis (bedwetting). In which stage of sleep do these occur? What medications shorten this stage of sleep and thus are useful in treating night terrors, sleepwalking, and enuresis? (FA14 p451) (FA15 p455)
Occur during stage N3 (non-REM 3)/slow wave sleep
Benzodiazepines (e.g., clonazepam)are useful for night terrors and sleep walking
Treat bedwetting with oral desmopressin acetate (DDAVP), which mimics ADH, preferred over imipramine because of the latter’s adverse effects
What medications are known for causing erectile dysfunction?
Antidepressants (SSRIs)
Antipsychotics
Spironolactone (anti-androgen effects)
Ketoconazole (anti-androgen effects and inhibits synthesis of steroid hormones in adrenals)
Cimetidine (stimulates prolactin release - can reduce testosterone levels)
Sympathetic blockers (Clonidine, methyldopa, guanethidine)
Thiazide diuretics
Beta blockers (may be placebo effect)
A 48-year-old woman who has taken oral contraceptive pills for the past 15 years is concerned because she is not experiencing menopausal symptoms like the rest of her friends her age. What is the primary reason why menopausal women experience symptoms? Why might this patient not be experiencing menopausal symptoms? What symptoms/conditions are attributed to the changes that take place in menopause? (FA14 p571, 590) (FA15 p576, 596)
Menopause occurs because of decreased estrogen production due to age related decline in number of ovarian follicles. It is the decreased estrogen that causes the symptoms
Patient is not having symptoms because she is getting estrogen in her OCP
Menopause causes HAVOCS: Hot flashes, Atrophy of the Vagina/dryness, Osteoporosis, Coronary artery disease, Sleep disturbances
What is the rule of 2s associated with a Meckel diverticulum? (FA14 p356) (FA15 p364)
True diverticulum - persistence of vitelline duct (connects yolk sac to midgut). May contain ectopic-acid secreting gastric mucosa and/or pancreatic tissue. Most common congenital anomaly of the GI tract.
Five 2’s
2 inches long
2 feet from ileocecal valve
2% of the population
Commonly presents in the first two years of life
May have 2 types of epithelia (gastric/pancreatic)
A newly married couple is enjoying a honeymoon on a Caribbean beach in Mexico. A few days into the trip, the two begin complaining of abdominal cramps and watery diarrhea. They do not have fevers. Which type of Escherichia coli causes the very common “Travelers’ diarrhea”? (FA14 p139) (FA15 p138)
ETEC Enterotoxigenix E. coli
Toxin and mechanism: produces heat-labile and heat-stable enterotoxins. No inflammation or invasion
Presentation: Travelers diarrhea (watery not bloody)
