Question
Echocardiography shows a left to right shunt just above the muscular interventricular septum. An abnormality of which of the following structures most likely produced this infant’s defect? A. Chlordae tendineae B. Crista terminalis C. Endocardial cushion D. Septum primum E. Sinus venosus

Question
Which of the following portions of the nervous sysem form nerves that migrate with the myotomes during development? A. Dorsal primary ramus B. Ventral primary ramus C. Dorsal root ganglion D. Sympathetic ganglion E. Grey communicating ramus F. White communicating ramus

Question
A product of which of the following genes is most important in signaling by the ZPA? A. Fibroblast growth factor 8 B. Homeobox-B8 C. Sonic hedgehog D. Transforming growth factor-beta E. Transforming growth - alpho

Question
By the end of the fifth week, dorsomedial somatic cells give rise to myotomes forming the epimere. Which of the following muscles is most likely derived from these cells? A. Erector spinae B. Lateral pterygoid C. Latissimus dorsi D. Psoas major E. Sternocleidomastoid

Question
There is failure of midline fusion in the urogenital region. Chromosome analysis shows his karyotype is 46, XY. Which of the following is most likely responsible for his condition? A. Abnormal androgen levels in utero B. Failure of mesonephric ducts to reach the ...

Question
A pelvic ultrasound reveals a bicornuate uterus. Which of the following is the most likely explanation for her anomalous uterus? A. Excess circulating maternal androgens while in utereo B. Failure of primordial germ cell migration C. Failure of the paramesonerphric ducts to fuse D. ...

Question
The infant has no other abnormalities noted. Which of the following is the most likely abnormality involving the gonads of this infant? A. Agenesis B. Fusion C. Hypopituitarism D. Incomplete descent E. Leydig cell aplasia