Embryology Flashcards
What are defects in gastrulation?
Split-cord malformations, neurenteric/dermoid/epidermoid cyst, anterior meningoceles, and potentially teratomas
What are the three types of split-cord malformations?
Type I- diastematomyelia (two dystrophic SC separated by a bony bar with 2 dural tubes. Type II- diplomyelia (two dystrophic cords separated by a fibrous band contained within a single dural tube). Type III- complex SCM (one of the dystrophic hemicords forms an open NTD aka hemimyelomeningocele)
What is Meckel-Gruber syndrome?
neural tube defect, renal and limb abnormalities. Mut MKS1 and 3 genes associated with ciliogenesis
What POD does the anterior neuropore close and where?
Day 24. Embryonic lamina terminalis (future site of the anterior commissure)
What POD does the posterior neuropore close and where?
Day 26. S2.
The filum terminale and lower sacral levels are formed by _____ neurulation?
Secondary
What are the four main types of defects with primary neurulation?
Anencephaly, Cranioraschisis, Myelomeningocele, Myeloschisis
What causes meningoceles and meningocele manque?
Disorder of primary neurulation
What are dermoid cyst?
Contain mesoderm + ectoderm: Likely a failure of gastrulation but some think it may be late primary neurulation
What are epidermoid cyst and what is the pathologic buzz word?
composed only of ectodermal elements. “mother of pearl”
What are defects of disjunction?
Spinal lipomas (premature disjunction) and dorsal dermal sinuses (focal failures of disjunction)
What are three defects of secondary neurulation?
Abnormal/fatty filum terminale, terminal lipoma, myelocystocele, note: caudal regression and sacral agenesis- often associated with failure of caudal cell mass].
What are the two clinically relevant types of caudal agenesis?
Type I- truncated, high conus.
Type II- a tethered, low conus
What is VATER?
vertebral anomalies, imperforate anus, TE fistula, renal anomalies.
What is OEIS?
omphalocele, cloacal exstrophy, imperforate anus, spinal anomaly
