High Yield USMLE Flashcards

(89 cards)

1
Q

What is the direct impact of absence of Y chromosome during development?

A

Germinal ridge develops into ovaries; presence of Y chromosome causes germinal ridge to develop into testes.

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2
Q

Affect of UVB light on DNA?

A

Thymidine dimers

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3
Q

Inheritance pattern for xeroderma pigmentosum?

A

Autosomal recessive

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4
Q

Pathophysiology of xeroderma pigmentosum?

A

Absent DNA repair enzymes leads to increased incidence of UVB-related skin cancers

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5
Q

Cytochrome oxidase (oxidative phosphorylation) is inhibited by what two poisons?

A

CO and cyanide

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6
Q

Inheritance pattern for chronic granulomatous disease?

A

Majority are X-linked recessive, remaining are autosomal recessive.

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7
Q

Pathophysiology of chronic granulomatous disease?

A

Absent NADPH oxidase leads to absent respiratory burst (ability to form reactive oxygen species) leading to susceptibility to infection by catalase-positive organisms (ex: S. aureus, Listeria, E. coli, etc.)

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8
Q

What percent of patients in a study fall two standard deviations below the mean in a normal distribution curve?

A

2.5% (5% of the population is outside of two standard deviations on either side of the mean. Therefore, the population below two standard deviations on just one side of the mean = half of 5% = 2.5%).

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9
Q

A family tree for a disease shows that all the children (male and female) of a female are affected by the disease, but the children (male and female) of her brother are not. What inheritance pattern does this likely represent?

A

Mitochondrial (all babies get their mitochondria from Mom).

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10
Q

Most common vitamin deficiency in alcoholics? Most common mineral deficiency in alcoholics?

A

Folate

Magnesium

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11
Q

Vitamin cofactor for major dehydrogenases (pyruvate dehydrogenase, alpha-ketoglutarage dehydrogenase, branched chain FA dehydrogenase, etc.)?

A

Thiamine (vitamin B1)

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12
Q

Which cell(s) is/are affected most by a deficient NADPH oxidase system (CGD)?

A

Neutrophils and monocytes

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13
Q

What is caisson disease?

A

Decompression sickness: divers who come up too fast.

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14
Q

What is decreased when a diver comes up too quickly (in caisson disease)? I.e. what is the pathophysiology of the disease?

A

P(N2) (partial pressure of nitrogen) is decreased since nitrogen forms bubbles in the vessels and moves into the tissue.

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15
Q

DES exposure is associated with?

A

Clear cell adenocarcinoma of the vagina.

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16
Q

What is the precursor to clear cell adenocarcinoma of the vagina?

A

Vaginal adenosis

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17
Q

If one kidney undergoes damage, what happens to the other (what will you see on imaging)?

A

Hypertrophy; the other kidney is enlarged on imaging.

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18
Q

What are three main consequences of vitamin E toxicity in terms of hematology?

A
  1. Decreases levels of vitamin K-dependent factors.
  2. Increases incidence of hemorrhagic stroke.
  3. Potentiates the action of warfarin.
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19
Q

Biotin (vitamin B7) is most important for what reaction?

A

Carboxylase reactions (ex: conversion of pyruvate to oxaloacetate in Krebs cycle).

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20
Q

Cherry red macula = what disease(s)?

A

Tay-Sachs (also Niemann-Pick and less commonly others).

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21
Q

How is vitamin B6 important for the liver?

A

Important for transamination reactions (i.e. functioning of AST and ALT).

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22
Q

Chance of a male patient with CF having a child?

A

<5% (because the vas deferens never fully developed or are atretic).

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23
Q

Chance of female patient with CF having a child?

A

Higher than males, but still difficult due to thick cervical mucus.

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24
Q

What vitamin supplements are required in CF?

A

All the fat-soluble ones (A, D, E, and K).

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25
What cells does EBV infect? What is the receptor for EBV on these cells?
B cells; CD21.
26
Hypogonadism, mental retardation, and unilateral gynecomastia = ?
Klinefelter syndrome
27
Hypogonadism and color blindness = ?
Kallman syndrome (absent GnRH)
28
Hypogonadism, mental retardation, and retinitis pigmentosum = ?
Laurence-Moon-Biedl syndrome.
29
Male with hypogonadism, mental retardation, short stature, and webbed neck = ?
Noonan syndrome (similar to Turner's syndrome).
30
Hypogonadism + anosmia (lack of smell) = ?
Kallman syndrome
31
Male pseudohermaphrodite with cryptorchidism = ?
Testicular feminization; most commonly due to absent androgen receptors (X-linked recessive)
32
Microdeletion leading to hypogonadism, mental retardation, short stature, and obesity = ?
Prader-Willi syndrome (chromosome 15, deletion is of paternal origin with maternal chromosome silenced by imprinting).
33
Two major complications of cyclophosphamide use?
1. Hemorrhagic cystitis | 2. Transitional carcinoma of bladder
34
Employee that work in a car assembly plant present with headache, nausea, vomiting, muscle weakness, and abdominal cramps. Coworkers have similar symptoms = ?
Lead poisoning from batteries.
35
Newborn female with edema of hands and feet and cystic mass of neck = ?
Turner's syndrome (45 XO)
36
Key protein in cow's milk? Key protein in breast milk?
Casein; whey
37
What vitamin is absent in colostrum?
Vitamin D
38
Retinal hemorrhages in infant = ?
Abuse; shaken baby syndrome
39
Pruritic, discrete, bright red papules on legs and around the waist = ?
Chigger bites
40
Adults who overdose on aspirin develop what metabolic disorder?
Mixed metabolic acidosis + respiratory alkalosis
41
Children who overdose on aspirin develop what metabolic disorder?
Increased anion gap metabolic acidosis (not mixed).
42
Tx for child who overdoses on aspirin = ?
Gastric lavage and add activated charcoal to produce alkaline urine for increased excretion of acid.
43
Three common causes of angiosarcoma of the liver?
Vinyl chloride Arsenic Thorotrast
44
Low AFP in pregnancy = ?
Down syndrome
45
Two tumors that commonly secrete ACTH as part of paraneoplastic syndrome?
Small cell carcinoma of the lung | Medullary carcinoma of thyroid
46
Tumor that commonly secretes ADH as part of paraneoplastic syndrome?
Small cell carcinoma of the lung
47
Tumors that secrete beta-hCG as part of paraneoplastic syndrome?
Trophoblastic tumors: benign (hydatidiform mole and invasive mole), malignant (choriocarcinoma) + germ cell tumors of ovary and testes
48
Tumor that secretes calcitonin?
Medullary carcinoma of thyroid
49
Tumors that secrete erythropoietin?
Renal adenocarcinoma, Wilm's tumor, hepatocellular carcinoma, von Hippel-Lindau disease, kidney lesions (cysts, hydronephrosis), large uterine leiomyomas producing hydronephrosis
50
Tumors that secrete insulin-like growth factor?
Hepatocellular carcinoma, retroperitoneal tumors
51
Tumors that secrete PTH-like peptide (PTHLP)?
Squamous carcinoma of lung, renal adenocarcinoma, breast cancer, ovarian cancer
52
Tumors that secrete serotonin?
Carcinoid syndrome (metastatic small bowel carcinoid tumor AFTER it migrates to liver), small cell carcinoma of lung, bronchial carcinoid tumor, and medullary carcinoma of thyroid
53
Symptoms of excess ACTH?
Cushing syndrome (hyperpigmentation, moon facies, etc.)
54
Symptoms of excess ADH?
Diluted hyponatremia
55
Symptoms of excess beta-hCG?
Gynecomastia (LH analogue), hyperthyroidism (TSH analogue), and precocious puberty in children
56
Symptoms of excess calcitonin?
Hypocalcemia
57
Symptoms of excess erythropoietin?
Secondary polycythemia (normal PaO2, increased RBC mass, normal plasma volume)
58
Symptoms of excess insulin-like growth factor?
Hypoglycemia
59
Symptoms of excess PTH-like peptide?
Hypercalcemia (low PTH)
60
Symptoms of excess serotonin?
Carcinoid syndrome: flushing, diarrhea, valvular lesions (tricuspid insufficiency and pulmonic stenosis). Note: RIGHT side of the heart is affected; left side has neutralizing factors for serotonin.
61
Elevated AFP correlates with what tumors?
Hepatocellular carcinoma Germ cell tumors (yolk sac or endodermal sinus tumors of testicle or ovary) Testicular/ovarian cancer
62
Elevated AAT correlates with what tumors?
Hepatocellular carcinoma | Yolk sac or endodermal sinus tumors of testicle/ovary
63
Elevated beta-HCG correlates with what tumors?
Trophoblastic tumors of ovary/testes and placenta: benign (hydatidiform and invasive moles), malignant (choriocarcinoma)
64
Elevated beta-2-microglobulin correlates with what tumors?
Multiple myeloma (excellent prognostic factor); forms light chains in urine (Bence Jones proteins)
65
Elevated bombesin correlates with what tumors?
Small cell carcinoma of lung | Neuroblastoma
66
Elevated CA 15-3 correlates with what tumors?
Breast cancer
67
Elevated CA 19-9 correlates with what tumor?
Pancreatic cancer
68
Elevated CA 125 correlates with what tumor?
Surface-derived ovarian cancer
69
Elevated CEA correlates with what tumor?
``` Colorectal Pancreatic Breast Small cell cancer of lung *Bad prognostic sign if elevated preoperatively (greater incidence of undetected metastasis). ```
70
Elevated LDH correlates with what tumor?
Marker of Hodgkin's disease | Nn-specific tumor marker in general
71
Elevated neuron specific enolase (NSE) correlates with what tumor?
Small cell carcinoma of lung | Neuroblastoma
72
Elevated PSA correlates with what tumor?
Prostate adenocarcinoma
73
What are the four main oncogenic RNA viruses?
HTLV-1 HTLV-2 HIV HCV
74
What tumors does HTLV-1 cause?
Adult T cell leukemia/lymphoma
75
What tumors does HTLV-2 cause?
Hairy cell leukemia
76
What tumors does HIV cause?
CNS malignant lymphoma
77
What tumors does HCV cause?
Hepatocellular carcinoma
78
What are the four main oncogenic DNA viruses?
HBV EBV HPV (HSV-2 may act as a cocarcinogen) HSV-8
79
What tumors does HBV cause?
Hepatocellular carcinoma
80
What tumors does EBV cause?
Burkitt's lymphoma Nasopharyngeal carcinoma Polyclonal malignant lymphoma
81
What tumors does HPV cause?
``` Squamous carcinoma of the cervix/vagina/vulva/anus Laryngeal papillomas (may progress to cancer) ```
82
What tumors does HSV-8 cause?
Kaposi's sarcoma
83
What eating disorder is associated with secondary amenorrhea? How?
Anorexia nervosa (when BMI drops too low): decreases GnRH and gonadotropins
84
Most common cause of death in anorexia nervosa?
Ventricular arrhythmia
85
What kind of diet leads to kwashiorkor?
Decreased protein intake but normal caloric intake (all CHO).
86
Metabolic consequences/symptoms of kwashiorkor?
Fatty liver from decreased apolipoproteins, pitting edema, and flaky paint dermatitis
87
Define marasmus
Loss of muscle mass due to decreased total caloric intake
88
Symptoms of vitamin A deficiency?
Squamous metaplasia in eyes and bronchus (vitamin A is generally required to maintain specialized epithelium and can also cause pancreatic pathology when deficient), nyctalopia
89
Symptoms of vitamin A toxicity?
Increased intracranial pressure, hypercalcemia