Embryology and Development — Flashcards

Flashcard 41: In _____ ossification, osteoblasts and osteoclasts replace cartilage with a matrix of woven bone and then remodel to lamellar bone.

Answer: endochondral

Flashcard 42: Each otic vesicle divides into a dorsal component called _____ and a ventral component called pars inferior.

Answer: pars superior

Flashcard 43: Y-shaped sutures are characteristic of the _____ nucleus of the lens.

Answer: fetal

Extra: In the fetal nucleus, the anterior suture is an upright 'Y' and the posterior suture is an inverted 'Y'. The embryonic nucleus has no sutures, while the infantile and adult nuclei have more complex star-shaped (dendritic) sutures.

Flashcard 44: The _____ duct connects the yolk sac to the midgut lumen

Answer: vitelline

Flashcard 45: Two common first arch syndromes are _____ syndrome and pierre robin sequence

Answer: treacher-collins

Flashcard 46: The _____ bud is derived from the caudal end of the mesonephric duct

Answer: ureteric

Flashcard 47: Fetal erythropoiesis occurs in the _____ from 8 weeks to birth

Answer: liver

Flashcard 48: The embryonic _____ gives rise to the smooth part of the right atrium

Answer: right horn of sinus venosus

Flashcard 49: In the developing ovaries, primordial germ cells produce _____ by mitotic divisions until gestational weeks 20 to 24

Answer: oogonia

Flashcard 50: _____ part of the tongue and the epiglottis is derived from the third swelling in the posterior part of the 4th arch

Answer: Posterior-most