Embryology Flashcards
1st aortic arch derivatives
part of maxillary artery (branch of external carotid)
2nd aortic arch derivatives
stapedial artery and hyoid artery
3rd aortic arch derivatives
common carotid artery and proximal part of internal carotid artery
4th aortic arch derivatives
on left, aortic arch; on right, proximal part of subclavian artery
6th aortic arch derivatives
proximal part of pulmonary arteries and (on left only) ductus arteriosus
truncus arteriosus gives rise to [?]
ascending aorta and pulmonary trunk
bulbus cordis gives rise to [?]
smooth parts (outflow tract) of left and right ventricles
primitive ventricle gives rise to [?]
trabeculated part of left and right ventricles
primitive atrium gives rise to [?]
trabeculated part of left and right atria
left horn of sinus venosus gives rise to [?]
coronary sinus
right horn of sinus venosus gives rise to [?]
smooth part of right atrium (sinus venarum)
endocardial cushion gives rise to [?]
atrial septum, membranous interventricular septum; AV and semilunar valves
right common cardinal vein and right anterior cardinal vein gives rise to [?]
superior vena cava
posterior cardinal, subcardinal, and supracardinal veins gives rise to [?]
inferior vena cava
primitive pulmonary vein gives rise to [?]
smooth part of left atrium
ductus arteriosus postnatal derivative = [?]
ligamentum arteriosum
ductus venosus postnatal derivative = [?]
ligamentum venosum
foramen ovale postnatal derivative = [?]
fossa ovalis
allantois -> urachus postnatal derivative = [?]
median umbilical ligament
umbilical arteries postnatal derivative = [?]
medial umbilical ligaments
umbilical vein postnatal derivative = [?]
ligamentum teres hepatis (round ligament)
embryonic stage of lung development
weeks 4-7
lung bud => trachea => bronchial buds => mainstream bronchi => secondary (lobar) bronchi => tertiary (segmental) bronchi
errors at this stage = tracheoesophageal fistula
pseudoglandular stage of lung development
weeks 5-17
endodermal tubules => terminal bronchioles
canalicular stage of lung development
weeks 16-25
terminal bronchioles => respiratory bronchioles => alveolar ducts; surrounded by prominent capillary network
respiration capable at week 25
saccular stage of lung development
week 24-birth
alveolar ducts => terminal sacs (separate by primary septae)
alveolar stage of lung development
week 26-8 years
terminal sacs => adult alveoli (secondary septation)
[?] is remnant of thyroglossal duct
foramen cecum
[?] presents as an anterior midline neck mass that moves with swallowing or protrusion of the tongue
thyroglossal duct cyst
vs. persistent cervical sinus leading to pharyngeal cleft cyst in lateral neck
thyroid follicular cells are derived from [?]; parafollicular cells arise from [?]
thyroid follicular cells are derived from endoderm; parafollicular cells arise from 4th pharyngeal pouch
foregut derivatives
esophagus to duodenum
supplied by celiac artery and vagus nerve
midgut derivatives
lower duodenum to proximal 2/3 of transverse colon
supplied by SMA and vagus nerve
hindgut derivatives
distal 1/3 of transverse colon to anal canal above pectinate line
supplied by IMA and pelvic parasympathetic innervation
physiologic herniation of midgut through umbilical ring occurs during [?] week of development
6th
midgut returns to abdominal cavity + rotates around SMA at [?] week of development
10th
pancreas (derived from foregut): ventral pancreatic bud contributes to [?]; both ventral and dorsal buds contribute to [?]
ventral pancreatic bud contributes to uncinate process; both ventral and dorsal buds contribute to pancreatic head and pain pancreatic duct
what are the retroperitoneal structures?
SAD PUCKER
suprarenal (adrenal) glands
aorta and IVC
duodenum (2nd-4th parts)
pancreas (except tail)
ureters
colon (descending and ascending)
kidneys
esophagus (thoracic portion)
rectum (partially)
branches of celiac trunk include [?]
common hepatic, splenic, and left gastric arteries (supply foregut)
mutations in sonic hedgehog (SHH) gene result in [?]
holoprosencephaly
the [?] gene is responsible for anterior-posterior axis patterning and CNS development
sonic hedgehog gene
the [?] gene is responsible for dorsal-ventral axis patterning and limb development
Wnt-7
the [?] gene is responsible for limb lengthening, via mitosis of the mesoderm
fibroblast growth factor (FGF) gene
the [?] gene is responsible for segmental organization in cranial-caudal direction, transcription factor coding
homeobox (Hox) genes
mutations in homeobox (Hox) genes result in [?]
appendages in the wrong locations
week [?] = hCG secretion begins
week 1 (around the time of blastocyst implantation, day 6)
week [?] = formation of bilaminar embryonic disc
week 2 (epiblast, hypoblast)
week [?] = trilaminar embryonic disc via gastrulation
week 3 (endoderm, mesoderm, ectoderm)
[?] arises from midline mesoderm and induces overlying ectoderm to become neural plate
notochord
week [?] = heart begins to beat; upper and lower limb buds begin to form
week 4
week [?] = genitalia have male/female characteristics
week 8
surface ectoderm derivatives
“you CLEAN the surface with SOAP”
anal Canal
lens
epidermis
adenohypophysis (anterior pituitary)
nipple (mammillary gland)
sweat gland
olfactory epithelium
auditory organs
parotid gland
neural tube derivatives
“a tube of NEASPOREN”
NEural tube
astrocytes
spinal cord
pineal gland
oligodendrocytes
retina
ependymal cells
neurohypophysis (posterior pituitary)
neural crest derivatives
“SPAMS MOTEL with crest toothpaste”
Schwann cells
PNS
adrenal medulla
myenteric plexus
spiral membrane
melanocytes
odontoblasts
thyroid C-cells
endocardial cushion
laryngeal cartilage
mesoderm derivatives
musculoskeletal (muscle, bone, connective tissue, serous linings of body cavities [peritoneum, pericardium pleura]), spleen, cardiovascular structures, lymphatics, blood, wall of gut tube, proximal kidneys, adrenal cortex, dermis, testes, ovaries, microglia, dura mater, tracheal cartilage
endoderm derivatives
gut tube epithelium (including anal canal above pectinate line), most of urethra and distal vaginal, luminal epithelial derivatives (lungs, liver, gallbladder, pancreas, eustachian tube, thymus, parathyroid, thyroid follicular and parafollicular cells)
mesoderm defects result in [?]
“watch Malcom in the Middle on a CLEAR TV”
cardiac defects
limb defects
esophageal defects
anal atresia
renal defects
tracheal defects
vertebral defects
the decidua basalis is derived from [?]
maternal endometrium
the umbilical cord is composed of [?]
two umbilical arteries (return deoxygenated blood from fetal internal iliac arteries to placenta) and one umbilical vein (supplies oxygenated blood from placenta to fetus)
the intra-abdominal remnant of allantois is the [?]
urachus (a duct between fetal bladder and umbilicus)
the [?] connects the yolk sac to the midgut lumen
vitelline duct; obliterates during week 7 of development
branchial clefts are derived from what embryological layer?
ectoderm
branchial arches are derived from what embryological layer?
mesoderm + neural crest
branchial pouches are derived from what embryological layer?
endoderm
branchial arch/pouch 1 derivatives
“M S 2 Problems are Vague”
muscles of mastication
Meckel’s cartilage
maxilla
meatus (external acoustic)
middle ear
mastoid air cells
maxillary artery
mylohyoid
trigeMinal nerve V3
branchial arch/pouch 2 derivatives
“M S 2 Problems are Vague”
stapes
styloid
stylohyoid
stapedius
smiling (facial nerve)
stapedial artery
branchial arch/pouch 3 derivatives
“M S 2 Problems are Vague”
stylopharyngeus
glossopharyngeal nerve
Parathyroid glands (inferior)
internal and common parotid arteries (problem if severed)
branchial arch/pouch 4/6 derivatives
“M S 2 Problems are Vague”
superior laryngeal (4)
recurrent laryngeal (6)
arytenoids, cricoid, corniculate, thyroid, superior parathyroid, ultimobranchial body, parafollicular cells
pulmonary arteries + ductus arteriosus (left)
cleft lip is due to failed fusion of the [?]
intermaxillary segment (merged medial nasal processes) with the maxillary process (formation of primary palate)
cleft palate is due to failed fusion of the [?]
two lateral palantine shelves or failure of fusion of lateral palantine shelf with the nasal septem
notochord becomes [?] in adults
nucleus pulposus of intervertebral disc
telencephalon division of prosencephalon: derivatives
walls: cerebral hemispheres, basal ganglia
cavities: lateral ventricles
diencephalon division of prosencephalon: derivatives
walls: thalamus, hypothalamus, retina
cavities: third ventricle
mesencephalon derivatives
walls: midbrain
cavities: cerebral aqueduct
metencephalon division of rhombencephalon: derivatives
walls: pons, cerebellum
cavities: upper part of fourth ventricle
myelencephalon division of rhombencephalon: derivatives
walls: medulla
cavities: lower part of fourth ventricle
