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Flashcards in Embryo Deck (31):

Truncus arteriosus and Bulbus cordis ->

Spiral and fuse to form ascending Ao and pulm trunk, and smooth (outflow) part of ventricles


How do heart septums form?

1) Muscular ventric septum (leaves interventric foramen)
2) AP septum forms mem inter-ventric septum, closes hole
3) Endocardial cushions do rest (AV mem, btwn atrial and part of btwn ventricles)


How does the interatrial septum develop?

1) Septum 1* gets rid of foramen 1*
2) Holes in septum1* form foramen2*
3) Foramen2* is R->L shunt as septum2* grows but keeps opening (foramen ovale)
4) Foramen2* enlarges, takes over septum1*, but little bit of it remains as valve of foramen ovale
5) Septum1* and 2* fuse to form atrial septum, and foramen ovale closes after birth


Where does fetal erythropoiesis occur?

"Young Liver Synthesizes Blood"
Yolk sac, 3-10wks
Liver, 6wks-birth
Spleen, 15-30wks
BM, 22wks-adult


Fetal postnatal deriv's:
- umbilical v.
- umbilical a's
- allantois
- notochord

- ligamentum teres hepatis in falciform lig
- mediaL umbilical lig's
- urachus-mediaN umbilical lig; urachal cyst/sinus is remnant
- nuc pulposus of intervertebral disc


Thyroid comes from?
Connected to tongue by?
- cyst of this presents as?

Floor of primitive pharynx, descends into neck
- Thyroglossal duct -> foramen cecum in adults (hole in back of tongue)
- thyroglossal duct cyst: ant midline neck mass that moves w/ swallowing


Cyst in ant midline of neck?
Cyst in lat neck?

- thyroglossal duct cyst
- branchial cleft cyst from persistent cervical sinus (from 2-4th branchial clefts, should go away)


Ab wall defects, failure of __ -> ?
- rostal fold closure failure?
- lat fold closure failure?
- caudal fold closure failure?

- sternal defects
- omphalocele (ab contents covered by peritoneum), gastroschisis (ab contents freely out)
- bladder exstrophy


Duo atresia is due to? assoc'd w/?
Jejunal, ileal, colonic atresia due to?

- failure to recanalize, Tri21
- vasc accident (apple peel atresia bc affected area has spiral look)


When do the ab contents go out and come back into fetus?

Wk6 - midgut herniates thr um ring
Wk10 - returns to ab cavity + rotates around SMA


Most common tracheoeso anomaly?
- Presents as?
- Cyanosis from?
- test by?

Eso atresia w/ Tracheoesophageal fistula
- drooling, choking and V w/ first feeding; air in stomach on CXR
- laryngospasm to avoid reflux-related aspiration
- can't put NG tube into stomach


Nonbilious projectile V at ~2wks old, w/ palpable olive mass in epigastric region = ?
- trtmt?

Congenital pyloric stenosis, more often in firstborn males
- surgical incision


Panc is made from which part of gut?
- what are the 2 buds?
- uncinate process =

- Ventral bud (head and main duct) and Dorsal bud (everything else)
- from ventral bud, hood btwn 2 buds


Annular panc =
Panc divisum =

- ventral bud encircles 2nd part of duo -> ring of panc tissue, may narrow duo
- ventral and dorsal parts don't fuse at 8wks


Spleen tissue is which of the 3 types?
- bl comes from?

Mesodermal (made from mesentery of stomach)
- Celiac art. (foregut)


Alar plate vs. basal plate of neural tube?

Alar plate is dorsal sensory side of neural tube, basal plate is ventral motor side


Forebrain, aka ?
Becomes in adult? (walls and cavities)

- telencephalon -> CeC, lat ventricles
- diencephalon -> thalamus, 3rd ventricle


Midbrain, aka ?
Becomes in adult? (walls and cavities)

- midbrain, aqueduct


Hindbrain, aka ?
Becomes in adult? (walls and cavities)

- Metencephalon -> pons and Ce, upper part of 4th ventricle
- Myelencephalon -> medulla, lower part of 4th ventricle


Spinal tube defect:
- 2 lab markers?
- due to?

- incr'd AFP in amniotic fluid and mat serum, incr'd AChE in amniotic fluid
- failure of neuropores to fuse at wk4


Meningocele vs. meningomyelocele?

Meninges but not SC out thr spinal canal defect
Meninges and SC out thr canal defect


Chiari II (Arnold-Chiari malformation) =
- usu presents w/?

Ce tonsillar and vermian herniation thr foramen magnum, also aqueductal stenosis and hydrocephalus
- myelomeningocele and paralysis below that


Dandy-Walker malformation =
- assoc'd w/?

Agenesis of Ce vermis w/ cystic enlargement of 4th ventricle
- hydrocephalus and spina bifida


Syringomyelia =
- assoc'd w/?
- usu at what level?

cystic enlargement of central canal of SC -> damages Xing fibers of spinothal tract -> bilat loss of pain/T in cape-like pattern
- Chiari I malformation (sm Ce tonsillar ectopia)
- C8-T1


Ant 2/3: arch? sensation? taste?
Post 1/3: arch? sensation? taste?
Motor innvervation?
M's from which myotome?

- 1st, V3, VII
- 3/4th, IX, IX (extreme post by X)
- occipital myotomes


Pronephros - wk?
Mesonephros - works when? becomes?
Metanephros - appears when? becomes?
- Ureteric bud: from? makes?
- Metanephric mesenchyme becomes?

- 4, then degen's
- kidney for 1st trim; contributes to male genital system
- appears in 5th wk, perm kidney
- caudal mesonephros; ureter, pelvises, calyces, CDs; works by wk10
- glom->DCT


Most common site of obstruction in kidneys?

Ureteropelvic jxn bc is last to canalize -> hydronephrosis if obstructed


Horseshoe kidneys:
- Trapped under?
- Assoc'd w/?

Turner's synd


Potter's synd
- cause of death in baby?
- assoc'd w/ (3)?

- pulm hypoplasia
- ARPKD, post urethral valves, bilat renal agenesis


Multicystic dysplastic kidney, due to?
- if unilat is?

abnl interaction btwn ureteric bud and metanephric mesenchyme (needed to make glom->DCT) -> nonfunc'ing kidney w/ cysts and ct in it
- asymp, compensatory hypertrophy of other kidney


Course of the ureters?

"Water under the bridge"
- Under uterine a./ductus deferens (retroperitoneal)