USMLE RX Flashcards
Wide spaced eyes and epicentral folds, with one fewer crease in palm that expected; eye examination shows white spots on the peripheral iris and extra autosomal chromosome. A/w with duodenal atresia
Down syndrome
What autosomal trisomy is a/w holoprosencephaly?
patau syndrome; trisomy 13
What autosomal trisomy is a/w ALL?
21
_____ is associated with midline facial defects such as cleft lip/palate and with coloboma (missing tissue in the risk, retina, choroid, or optic nerve), and is most commonly seen with trisomy 21?
holoprosencephaly
Malignant melanoma, characterized by irregular borders, ulceration, radial and vertical growth, and sun exposed location, originates from?
neural crest cells (melanocytes)
elevated AFP levels in amniotic fluid and maternal serum can be a sign of what?
neural tube defects such as meningocele and meningomyelocele
What are the 23 (1N, 1C) cells that are formed from secondary spermatocytes after meiosis 2 is completed. They undergo morphologic changes to become mature sperm that include acrosome, head, neck and tail.
spermatids
The arytenoid cartilages arise as swellings form what embryological orgin at 32 days of gestation?
6th pharyngeal arch
In the absence of mullerian inhibitory factor, the mullerian ducts develop into:
the Fallopian tubes, the uterus and the superior proximal portion of the vagina
In the presence of MIF, which is produced and secreted by the Sertoli cells, the mullerian ducts degenerate but may remain as vestigial remnant called
the appendix testes
The mesonephric ducts develop into the male internal genital structures, with the exception of the prostate from the urogenital sinus. Remember what structures?
BEEDS: bladder trigone, epididymis, ejaculatory duct, ductus deferens, seminal vesicles
Mediastinal deviation can occur with a diaphragmatic hernia, with mediastinal deviation in what direction from of the herniation,almost always the left hemithorax
away from the side of the herniation
Failure of the diaphragm to properly form and close leads to
congenital diaphragmatic hernia
true/false: Herniation of the bowel into the thorax may cause a shift in mediastinal structures to the contralateral hemithorax, which can manifest as heart sounds best appreciated in the right hemithorax.
true
developing diaphragm develops from
septum transversum, pleuroperitoneal folds, body wall, and dorsal mesentery of the esophagus
Failure of _____ to form leads to diaphragmatic hernias, with bowel sounds in lung zones
pleuroperitoneal folds (membrane)
Turner syndrome patients have coarctation of the aorta, a congenital narrowing of the descending aorta, usually just distal to the origin of the left subclavian artery and opposite to the dual arteriosus. what kind of coarctation is this?
juxtaductal coarctation
what can result in a small left arm due to compromised blood flow if the left subclavian artery is involved
juxtaductal coarctation
Beta hCG has a distinctive alpha subunit; which it shares with what other hormones?
TSH, LH, and FSH
acute onset abdominal pain with/without rebound tenderness. what to include in your differential?
ectopic pregnancy
What can result in deafness, PDA, pulmonary artery stenosis,cataracts and microcephaly?
congenital rubella infection
Bone deformity of the nasal bridge or saddle nose, is seen in what?
congenitally acquired syphilis
What condition can impinge on the crossing fibers of the spinothalamic tract, resulting in bilateral loss of pain and temperature sensation in the upper extremities?
syringomyelia
Inability to pass meconium and the finding of an empty rectum?
hirschprung disease or congenital megacolon
failure of neural crest cells to migrate into the bowel wall during embryogenesis and is characterized by the absence of ganglion cells in the large bowel , typically in the rectum and the adjacent segment of the distal colon that is immediately proximal to the rectum.
Hirschsprung disease or congenital megacolon
Folic acid is a coenzyme for 1 carbon transfers, decreases what in the fetus when taken in adequate amounts by the mother ?
neural tube defects ( ; exerts influence on neural folds in developing embryo)
elevating the palate and pharynx use what embryological structures?
branchial arches 1,3,4
What embryologic origin gives rise to the superior parathyroid glands and ultimobranchial body, which forms the parafollicular C cells (adjacent to the thyroid follies)
4th pharyngeal pouch
Meckel diverticulum is the MC congenital anomaly of the GI tract, it is a blind pouch protruding from the ileum, it is derived from ?
midgut
What aortic arch gives rise to the common carotids as well as the proximal internal carotid arteries
third
PDA is located in what arch?
sixth aortic arch
Bell’s palsy is a lesion of CN 7, and affects the muscles of facial expression. What is the embryological origin of this nerve?
2nd branchial arch
large cranium, small jaw, low set ears, and overlapping fingers
trisomy 18
What teratogen is a/w fetal thrombocytopenia and jaundice?
chlorothiazide
What teratogen is a/w permanent tooth staining, enamel hypoplasia, and diminished growth of long bones
doxycycline
What teratogen is a/w fetal cardial abnromalities and malformations of the great vessels
lithium
2 high risk consequences of coarctation of the aorta are?
bacterial endocarditis and cerebral hemorrhage
