Set 9

Question 1

A person eating fugu sashimi in Japan is at risk of what toxicity? What is the mechanism of this toxicity?

Answer 1

Fugu = pufferfish
Tetrodotoxin - neurotoxin that binds to voltage-gated sodium channels —> prevents depolarization
Can cause come, respiratory arrest, cardiovascular collapse

Question 2

You are performing a well-child examination on a 4-year-old girl. The patient was recently adopted after being removed from the biological mother for abandonment.
What changes might you see in your evaluation?

Answer 2

Poor care
Neglect
Depression
Malnutrition (short stature, low weight)
Hygiene (dental caries, skin infections - scabies)

Question 3

What are the effects seen in an infant when there is long-term deprivation of affection?

Answer 3

Long-term deprivation of affection in infants results in:

• Decreased muscle tone
• Poor language skills (loss of eye contact)
• Poor socialization skills
• Lack of basic trust
• Anaclitic depression (infant withdrawn/unresponsive)
• Weight loss
• Physical illness
• Failure to thrive

4 W’s: Weak, Wordless, Wanting (socially), Wary
Deprivation for greater than 6 months can lead to irreversible changes
Severe depression can result in infant death

Question 4

Which antifungal drugs cause gynecomastia and by what mechanism? What diuretic drug causes gynecomastia and by what mechanism?

Answer 4

Azoles (ketoconazole) - via testosterone synthesis inhibition (inhibits desmolase - converts cholesterol to pregnenolone). Secondary mechanism = androgen receptor antagonist (weak).

Spironolactone - Aldosterone antagonist and K+ sparing diuretic. Via antiandrogen effects - increases conversion of testosterone to estradiol and blocks testosterone synthesis. Also has some androgen receptor antagonism effects

Question 5

List the drugs that cause gynecomastia

Answer 5

"Some Drugs Cause Awesome Knockers”
Spironolactone
Digitalis
Cimetidine
Alcohol
Ketoconazole

Question 6

A 25-year-old woman presents to the clinic with severe pelvic pain that is always associated with menses. What diagnosis is characteristic of this type of pain and often results in infertility? What is the classic finding on the ovary that is associated with this diagnosis?

Answer 6

Endometriosis 
Chocolate cyst (endometrioma)

Question 7

What are the early cyanotic heart diseases? What are the late cyanotic heart diseases?

Answer 7

Early - blue babies, diagnosed prenatally or evident immediately after birth. 5 T’s: Truncus arteriosus, Transposition, Tricuspid atresia, Tetralogy of fallot, Total anomalous pulmonary venous return (TAPVR)

Late - blue kids. VSD, ASD, PDA

Question 8

How many half-lives does it take for a drug infused at a constant rate to reach 94% of steady state? What variables determine the half-life of a drug?

Answer 8

4-5 half-lives (1-50% 2-75% 3-87.5% 4-93.75%) to reach steady state
Volume of distribution, clearance

Question 9

Equation for half-live

Answer 9

(0.7 x Vd) / Clearance

Question 10

Describe the anatomical layers of the penis.

Answer 10

Outer dermis
Dartos fascia
Deep (Buck’s) fascia 
Tunica albuginea (3 cavernous tissue sections encased and separated by TA)
Corpora cavernosa (2)
Corpus spongiosum (1)
Urethra

Question 11

What is the mechanism of action of penicillin? Is it a bacteriostatic or bactericidal antibiotic?

Answer 11

*Blocks synthesis of bacterial cell walls by inhibiting the cross-linking of the peptidoglycan making the cell wall

Bind penicillin-binding proteins (traspeptidases)
Block transpeptidase cross-linking of peptidoglycan
Activate autolytic enzymes

*Bactericidal

Question 12

What is the adult remnant of the following fetal structures? 
Gubernaculum (female)
Processus vaginalis (male)
Foramen ovale
Notochord

Answer 12

Gubernaculum (female) - Ovarian ligament and round ligament of uterus
Processus vaginalis (male) - Forms tunica vaginalis 
Foramen ovale - Fossa ovalis 
Notochord - Nucleus pulposus of the intervertebral disc

Question 13

A 37-year-old patient with refractory peptic ulcer disease undergoes an esophagogastric duodenoscopy (EGD). Biopsies of the duodenum reveal hypertrophied submucosal glands. What are these glands? What are Peyer’s patches? How can these structures help you identify the location from which a histological specimen was taken?

Answer 13

Brunner’s glands - located in duodenal submucosa. Secrete alkaline mucus. Hypertrophy seen in peptic ulcer disease

Peyer’s patches- unencapsulated lymphoid tissue found in lamina propria and submucosa of ileum. Part of MALT (mucosa associated lymphoid tissue). Contain specialized M cells that sample and present antigen to immune cells