Embryology Flashcards
Holoprosencephaly can result from deficiency of which gene?
Sonic hedgehog
Give the basic role in embryogenesis of each of the following genes: sonic hedgehog, Wnt-7, FGF, homeobox
SHH - antero-posterior patterning, Wnt-7 - dorsal-ventral patterning, FGF - limbs, Homeobox - segmentation
Defect of which gene can lead to synpolydactyly (fusion of supranumery digits)
HOXD13
What is the anterior pituitary an embryological derivative of?
Rathkes pouch, which is a derivative of surface ectoderm
What structures does the neural crest give rise to (12)
ANS, DRG, CNs, Celiac ganglion, Melanocytes, Adrenal medulla, Parafollicular cells of thyroid, Schwann cells, Pia and arachnoid, bones of skull, odontoblasts, aorticopulmonary septum
What is the embryologic derivation of melanocytes, the adrenal medulla, and parafollicular cells of the thyroid respectively?
All are from neural crest
VACTERL
Mesodermal defects. Vertebral defects, Anal atresia, Cardiac defects, TE fisula, Renal defects, Limb defects (bone and muscle)
Teratogenic effect of ACE inhibitors
Renal damage
Teratogenic effect of alkylating agents
Absence of digits, multiple anomalies
Teratogenic effect of aminoglycosides
CN 8 toxicity
Teratogenic effect of carbamazepine
Neural tube defects, craniofacial defects, fingernail hypoplasia, developmental delay, IUGR
Teratogenic effect of lithium
Ebsteins anomaly (atrialized right ventricle)
Teratogenic effect of phenytoin
Fetal hydrantoin syndrome - microcephaly, dysmorphic craniofacial features, hypoplastic nails and distal phalanges, cardiac defects, IUGR, MR
Teratogenic effect of tetracyclines
discolored teeth
Teratogenic effect of valproate
Inhibits maternal folate absorption - neural tube defects
Teratogenic effect of warfarin
Bone deformities, fetal hemorrhage, abortion, ophthalmologic abnormalities
What teratogen is associated with ADHD?
Smoking
Effects of maternal diabetes on the fetus
Caudal regression syndrome (anal atresia to sirenomelia), congenital heart defects, neural tube defects
Microcephaly, holoprosencephaly, facial abnormalities (cleft lip and palate), limb dislocation, heart and lung fistulas, MR
Fetal alcohol syndrome
What is the embryonic predecessor to the ascending aorta and pulmonary trunk
Truncus arteriosus
What is the embryonic predecessor to the RV and smooth parts of the LV and RV
Bulbus cordis
What is the embryonic predecessor to the trabeculated LV and RV
Primitive ventricle
What is the embryonic predecessor to the trabeculated LA and RA
Primitive atria
What is the embryonic predecessor to the coronary sinus?
Left horn of the sinus venosus
What is the embryonic predecessor to the smooth part of the RA?
Right horn of the SV
What is the embryonic predecessor to the SVC?
Right common cardinal vein and right anterior cardinal vein
What heart defect is found in 20 to 30 percent of healthy adults?
Patent foramen ovale
Give the fetal precursors for each of the following: umbilical vein, umbilical arteries, allantois, and notochord
Umbilical vein - ligamentum teres hepatis, umbilical arteries - medial umbilical ligaments, allantois - urachus-median umbilical ligament, notochord - nucleus pulposus of IV discs
From what embryonic structure does the aqueduct of sylvius arise?
Mesencephalon
Two causes of increased aFP during pregnancy
Neural Tube Defect and anterior abdominal wall defect (omphalocele)
In syringomyelia what is in large, what is it associated with, and where does this most often occur?
Central canal of the spinal cord, Chiari II, C8-T1
3rd aortic arch derivatives
Common carotid and proximal part of the internal carotid
6th aortic arch derivatives
Proximal part of pulmonary arteries and ductus arteriosus
What are the branchial clefts, arches, and pouches derived from respectively?
Clefts - ectoderm, arches - mesoderm and neural crests, pouches - endoderm
A thyroglossal duct cyst is midline while a branchial cleft cyst is lateral. What is another easy way to tell them apart?
Branchial cleft cyst will not move on swallowing, thyrglossal duct cyst will
Fate of branchial clefts 1-4
1 - external auditory meatus, 2 through 4 are obliterated
Treacher Collins syndrome
Failure of 1st arch neural crest cells to migrate. Mandibular hypoplasia, facial abnormalities
Cartilage, muscles, and nerves of branchial arch 1
Mandible, Malleus, incus, spheno-Mandibular ligament. Muscles of Mastication, Myelohyoid, ant 2/3 of tongue muscles. V2 and V3
Cartilage, muscles, and nerves of branchial arch 2
Stapes, Styloid Process, lesser horn of hyoid, Stylohyoid ligament. Muscles of facial expression, Stapedius, Stylohyoid, post belly of digastric. CN 7
Cartilage, muscles, and nerves of branchial arch 3
Greater horn of hyoid. Stylopharyngeus. CN 9
Cartilage, muscles, and nerves of branchial archs 4-6
Thyroid, cricoid, arytenoid, corniculate, cuneiform cartilages. Cricothyroid lev veli palatini (4), intrinsic muscles of larynx except cricothyroid (6). CN 10 superior laryngeal br (4) and recurrent laryngeal branch (6)
What nerve is at risk during thyroidectomy and what muscle may this paralyze?
Superior laryngeal nerve. Cricothyroid muscle (both from branchial arch 4)
What is congenital pharyngeo-cutaneous fistula and what structure is it a defect in the development of?
Fistula between tonsillar area and clef in lateral neck. Branchial arch 3
What branchial arch forms the posterior third of the tongue?
Arches 3 and 4
Derivatives of branchial pouch 1
Middle ear cavity, eustachian tube, mastoid air cells
Derivatives of branchial pouch 2
Epithelial lining of palatine tonsil
Derivatives of branchial pouch 3
Inferior parathyroids (dorsal wings), and thymus (ventral wings)
Derivatives of branchial pouch 4
Superior parathyroids (dorsal wings)
DiGeorge syndrome is aberrant development of what embryonic structures?
Branchial pouches 3 and 4
Cleft lip results from failure of fusion of what structures?
Maxillary and medial nasal processes
Cleft palate results from failure of fusion of what structures?
Lateral palatine process, nasal septum, and/or median palatine process
Gastroschisis
Extrusion of abdominal contents through abdominal folds and not covered by peritoneum
Omphalocele
Persistence of herniation of abdominal contents into umbilical cord, covered by peritoneum
What obstructs the rise of a horseshoe kidney?
IMA
A bicornuate uterus results from failure to fuse of what structures?
The paramesonephric ducts
What cell produces anti-mullerian hormone?
Sertoli cell
