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: The embryonic _____ differentiates into renal structures from the glomerulus through the DCT

Answer: metanephric mesenchyme (blastema)

Flashcard 43: Each otic vesicle divides into a dorsal component called _____ and a ventral component called pars inferior.

Answer: pars superior

Flashcard 44: 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 45: If the developing embryo splits in the 2-cell stage (0-4 days), the twins will be _____ and diamniotic (# of chorions and # of amniotic sacs)

Answer: dichorionic

Flashcard 46: The _____ duct connects the yolk sac to the midgut lumen

Answer: vitelline

Flashcard 47: Two common first arch syndromes are _____ syndrome and pierre robin sequence

Answer: treacher-collins

Flashcard 48: _____ part of the tongue and the epiglottis is derived from the third swelling in the posterior part of the 4th arch

Answer: Posterior-most

Flashcard 49: The _____ - 4th branchial clefts form temporary cervical sinuses, which are obliterated

Answer: 2nd

Flashcard 50: The _____ (left) and proximal part of the right subclavian artery (right) are derivatives of the 4th aortic arch

Answer: true aortic arch