Embryo Flashcards
1st aortic arch derivative:
part of maxillary artery
1st branchial cleft derivative:
external auditory meatus
1st branchial arch derivative:
Meckel Cartilage: mandible, malleus, incus, spheno-mandibular lig Muscles of mastication (temporalis, masseter, lat/med pterygoids), mylohyoid, ant belly digastric, tensor tympani, tensor veli palatini CN V2 and V3
1st branchial pouch derivative:
Middle ear cavity, eustachian tube, mastoid air cells
2nd aortic arch derivative:
Stapedial artery and hyoid artery
2nd-4th branchial clefts:
temporary cervical sinuses, obliterated by prolif of 2nd arch mesenchyme
2nd branchial arch derivative:
Reichert cartilage: stapes, styloid process, lesser horn hyoid, stylohyoid lig Muscles of facial expression, stapedius, stylohyoid, platysma, post belly digastric CN VII
2nd branchial pouch derivative:
Epithelial lining of palatine tonsil
3rd aortic arch derivative:
Common carotid and prox part of internal carotid artery
3rd branchial arch derivative:
Cartilage: greater horn of hyoid Stylopharyngeus mm CN IX
3rd branchial pouch derivative:
Dorsal wings: inferior parathyroids Ventral wings: thymus ***End up BELOW 4th pouch structures
4th aortic arch derivative:
Left: aortic arch Right: prox part of right subclavian art
4th-6th branchial arch derivatives:
Cartilage: thyroid, cricoid, arytenoids, corniculate, cuneiform 4th arch: pharyngeal constrictors, cricothyroid, levator veli palatini, CN X superior laryngeal n. 6th arch: intrinsic mm of larynx except cricothyroid, CN X recurrent laryngeal n.
4th branchial pouch derivative:
Dorsal wings: superior parathyroids
6th aortic arch derivative:
Proximal part of pulmonary arteries, L side: ductus arteriosus
Paramesonephric ducts form what?
Fuse to form uterine tubes, uterus, cervix, upper 1/3 vagina Male: involute
Mesonephric ducts form what?
Male: epididymis, ductus deferens, seminal vesicles, ejaculatory ducts Female: Gartner’s ducts
Bicornuate Uterus due to failure of?
Fusion of paramesonephric ducts
Non-fusion of urethral folds causes:
Hypospadias (M), fuse to form ventral aspect of penis Vestibule of vagina (F)
Faulty positioning of the genital tubercle causes:
Epispadias (opening on dorsal surface of penis)
Common Cardinal Veins develop into what?
SVC and other veins of the systemic venous circulation
Vitelline veins form what?
Veins of the portal system
Umbilical veins form what?
Degenerate
Truncus arteriosus develops into what?
Ascending aorta, pulmonary trunk Neural crest cell migration partitions it into the two arteries by causing fusion and twisting of the truncal and bulbar ridges Failure results in transposition of great vessels/ToF
Bulbus cordis gives rise to:
Smooth parts (outflow track) of L and R V
Primitive atria give rise to:
Trabeculated part of L and R A
Primitive ventricle gives rise to:
Trabeculated part of L and R V
Primitive pulmonary vein gives rise to:
Smooth part of LA
Left horn of sinus venosus gives rise to:
Coronary sinus
Right horn of sinus venosus gives rise to:
Smooth part of RA (sinus venosum)
SVC develops from:
R common cardinal vein and R anterior cardinal vein
