Embryology — Flashcards

Flashcard 101: Bones of the calvarium, facial bones, and clavicle are formed via _____ ossification

Answer: membranous

Flashcard 102: What is the embryonic origin of thyroid tissue? _____

Answer: Endoderm

Extra: Atlas:

Flashcard 103: If the developing embryo splits during the **blastocyst stage (4-8 days)**, the twins will be _____-chorionic and _____-amniotic

Answer: mono

Extra: Mnemonic: **SCAB** - 0-4 days: **S**eparate (DiDi) - 4-8 days: shared **C**horion (MoDi) - 8-12 days: shared **A**mnion (MoMo) - >13 days: shared **B**ody (Conjoined)

Flashcard 104: Which embryologic structure develops into the seminal vesicles, epididymis, ejaculatory duct, and ductus deferens (male internal genitalia, except prostate)? _____

Answer: Mesonephric (wolffian) duct

Flashcard 105: The embryonic _____ interacts via reciprocal-inductive signaling with the ureteric bud, inducing differentiation of these tissues into their respective parts of the kidney

Answer: metanephric mesenchyme

Flashcard 106: What is the female remnant of the processus vaginalis? _____

Answer: None (obliterated)

Flashcard 107: What congenital renal defect is a condition of being born with only one functioning kidney (one non-functional)? _____

Answer: Congenital solitary functioning kidney

Flashcard 108: The umbilical arteries return deoxygenated blood from the fetal _____ arteries to the placenta

Answer: internal iliac

Flashcard 109: What congenital abnormality arises due to failure of fusion of the maxillary and medial nasal processes? _____

Answer: Cleft lip

Flashcard 110: Dandy-Walker malformation is associated with _____ and spina bifida

Answer: non-communicating hydrocephalus

Extra: * non-communicating b/c enlarged 4th ventricles squeezes cerebral aquadect impeding flow of CSF (stenosis of aqueduct of Sylvius) Dandy-Walker syndrome Cranial MRI of a young child (T2 weighted, sagittal view) The region of the posterior fossa and the pons appear cystic and hyperintense. The cerebellum also appears hypoplastic and the posterior fossa is enlarged. This radiographic appearance is suggestive of Dandy-Walker syndrome.