Embryology Flashcards
truncus arteriosius
ascending aorta and pulmonary trunk
bulbous cordis
smooth parts (outflow tract) of left and right ventricles
primitive atria
trabeculated part of left and right atria
primitive ventricle
trabeculated part of left and right ventricles
primitive pulmonary vein
smooth part of left atrium
left horn of sinus venosus (SV)
coronary sinus
right horn of SV
smooth part of right atrium
right common cardinal vein and right anterior cardinal vein
SVC
umbilical vein
ligamentum teres hepatis
umbilical arteries
medial umbilical ligament
ductus arteriosus
ligamentum arteriosum
ductus venosus
ligamentum venosum
foramen ovale
fossa ovalis
allantois
urachus-median umbilical ligament
notochord
nucleus pulposus of intervertebral disc
kidney embryology
pronephros (wk 4)–> mesonephros (1st trimester, contributes to male genital system)–> metanephros (permanent, ureteric buds, metenephric mesenchyme)
ureteric bud
- derived from caudal end of mesonephric duct
- gives rise to: ureter, pelvises, calyces, collecting duct
metanephric mesenchyme
- interacts w/ ureteric bud
- formation of glomerulus through distal convoluted tubule
1st aortic arch
maxillary artery (branch of external carotid) "1st arch is MAXimal"
2nd aortic arch
stapedial artery and hyoid artery
“Second=Stapedial”
3rd aortic arch
common carotid artery and proximal part of internal carotid artery
-“C is the 3rd letter of the alphabet”
4th aortic arch
left: aortic arch
right: proximal part of right subclavian artery
6th aortic arch
proximal part of pulmonary arteries and ductus arteriosus (left only)
Branchial apparatus derivatives
branchial clefts: ectoderm
branchial arches: mesoderm
branchial pouches: endoderm
1st cleft
external auditory meatus
2nd-4th cleft
temporary cervical sinuses (obliterated by proliferation of 2nd arch mesenchyme)
1st pouch
middle ear cavity, eustachian tube, mastoid air cells
2nd pouch
epithelial lining of palatine tonsil
3rd pouch
dorsal wings: inferior parathyroids
ventral wings: thymus
4th pouch
dorsal wings: superior parathyroid
1st branchial arch
cartilage: meckel cartilage (mandible, malleus, incus, sphenomandibular ligament)
muscles: muscles of mastication (temporalis, masseter, lateral and medial pterygoids), mylohyoid, anterior belly of digastric, tensory tympani, tensor veli palantini
nerves: V2 and V3
Treacher Collins sysndrome: 1st arch failes to migrate–> madibular hypoplasia, facial abnormalities
“M’s & T’s”
2nd branchial arch
cartilage: stapes, styloid process, lesser horn of hyoid, stylohyoid ligament
muscles: muscles of facial expression (stapedius, stylohyoid, platysma, belly of digastric)
nerves: CN VII (facial)
3rd branchial arch
cartilage: greater horn of hyoid
muscles: sylopharyngeus
nerve: CN IX (glossopharyngeal)
4th-6th branchial arches
cartilage: thyroid, cricoid, arytenoids, corniculate, cuneiform
muscles: 4th (pharyngeal constrictors, cricothyroid, levator veli palatini), 6th (all intrinsic muslces of larynx except cricothyroid)
nerves: 4th (CN X-superior laryngeal branch), 6th (CN X-recurrent laryngeal branch)
branchial arch derviatives mnemonic
“When at the restaurant of the golden ARCHES, children tend to first CHEW (1), then SMILE (2), then SWALLOW STYLishly (3) or SIMPLY SWALLOW (4), and then SPEAK (6)
paramesonephric (Mullerian) duct
develops into female internal structures
-fallopian tubes, uterus, upper portion of vagina
mesonephric (Wolffian) duct
develops into internal male structures (except prostate)
-seminal vesicles, epididymis, ejaculatory duct, ductus deferens
Genital tubercle
glans penis
glans clitoris
Genital tubercle
corpus cavernosum and spongiosum
vestibular bulbs
Urogenital sinus bulbourethral glands (of Cowper)
greater vestibular glands (of Bartholin)
Urogenital sinus
prostate gland
urethral and paraurethral glands (of Skene)
Urogenital folds
ventral shaft of penis (penile urethra)
labia minora
Labioscrotal swelling
scrotum
labia majora
Gubernaculum (band of fibrous tissue)
anchors testes w/in scrotum
ovarian ligament + round ligament uterus
Processus vaginalis (evagination of peritoneum) forms tunica vaginalis
obliterated
failed involution of urachus
drainage of urine from umbilicus
failed involution of vitelline (omaphalomesenteric) duct
drainage of meconium from umbilicus
22q11 syndrome
truncus arteriosus, tetrology of Fallot
Down syndrome
ASD, VSD, AV septal defect (endocardial cushion defect)
Congenital rubella
septal defects, PDA, pulmonary artery stenosis
Turner syndrome
bicuspid aortic valve, coarctation of aorta (preductal)
Marfan syndrome
MVP, thoracic aortic aneurysm and dissection, aortic regurgitation
Infant of diabetic mother
transposition of great vessels
forebrain (prosencephalon)
telencephalon
diencephalon
midbrain
mesencephalon
hindbrain (rhombencephalon)
metencephalon
myelencephalon
telencephalon
cerebral hemispheres
lateral ventricles
diencephalon
thalamus
third ventricle
mesencephalon
midbrain
aqueduct
metencehalon
pons
upper part of fourth ventricle
cerebellum
myelencephalon
medulla
lower part of fourth ventricle
agenesis
absent organ due to absent primordial tissue
aplasia
absent organ despite presence of primordial tissue
hypoplasia
incomplete organ development; primordial tissue pressent
deformation
extrinsic disruption; occurs after the embryonic period
disruption
secondary breakdown of previously normal tissue or structure
malformation
intrinsic disruption; occurs during embryonic period (weeks 3-8)
sequence
abnormalities result from single primary embryological event
ex: oligohydramnios–> Potter sequence
