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104 Cards in this Set

  • Front
  • Back
How long after fertilization will the blastocyst implant into the uterine wall?
~ day 6, definitely within first week
How many, and which, germ layers are present in week 2?
2 germ layers - Epiblast (recall: will invaginate to become primitive streak), and Hypoblast
How many cavities are present in week 2?
2 cavities - Amniotic cavity, and Yolk Sac
What happens within week 3?
Start forming primitive streak, notochord, neural plate
When does organogenesis take place?
Between weeks 3 and 8
When is am embryo particularly susceptible to teratogens?
Between weeks 3 and 8 - organogenesis and neural tube formation take place then!
When is the neural tube formed?
Day 18 - 21
When does the embryo heart begin to beat?
Week 4
When do the embryo's limbs start to form?
Week 4
When can you start to tell if the baby will be a boy or girl?
Week 10 - genitalia have male or female characteristics
How many germ layers are present in the 3rd week?
3 germ layers - ectoderm, mesoderm, endoderm
What is the primitive streak?
Primitive streak came from epiblast (bilaminar disc) and will eventually give rise to intraembryonic mesoderm and endoderm.
The anterior pituitary, lens of eye, epithelial linings, and epidermis all come from:
surface ectoderm
The posterior pituitary, CNS neurons, oligodendrocytes, astrocytes, ependymal cells, and pineal gland come from:
The bones of the skull, layngeal cartilage, and odontoblasts are derived from:
NEURAL crest (ectoderm)
The autonomic nervous system, dorsal root ganglia, cranial nerves, celiac ganglion, Schwann cells are derived from:
NEURAL crest (ectoderm)
The parafollicular cells of thyroid, chromaffin cells of adrenal medulla, enterochromaffin cells, pia, and arachnoid mater are derived from:
NEURAL crest (ectoderm)
Dura mater is derived from:
Connective tissue, bone, muscle, cardiovascular structures, lymphatics, blood, and spleen are derived from:
GU structures, serous linings of body cavities, adrenal cortex, and kidneys are derived from:
What structures are derived from endoderm?
Gut tube epithelium and derivatives (lungs, liver, pancreas, thymus, parathyroid, thyroid follicular cells)
What does the notochord do?
Induces ectoderm to form neuroectoderm (neural plate). Later becomes nucleus pulposus of intervertebral disc.
What is the leading cause of mental retardation in children?
fetal alcohol syndrome
How do ACE inhibitors affect fetal development?
renal damage
Is cocaine bad for pregnant women?
Yes, get abnormal fetal development and fetal addiction.
A young girl develops vaginal clear cell adenocarcinoma. Her mother most likely took what during pregnancy?
dietheylstilbestrol (DES)
A baby is born with flipper limbs. His mother was given what during pregnancy?
How does tobacco affect a fetus?
Preterm delivery, placental problems, ADHD
1 placenta, 1 chorion, and 2 amniotic sacs =
monozygotic twins
2 placentas, 2 chorions, 2 amniotic sacs =
either dizygotic or monozygotic twins
What structures are found inside the umbilical cord? (4)
- 2 arteries carrying deoxygenated blood from fetus back to mom
- 1 vein carrying 80% saturated O2 blood to baby
- allantoic duct removes nitrogenous waste from baby, like a urethra
What is a single umbilical artery associated with?
chromosomal and congenital anomalies
Truncus arteriosis -->
ascending AO and pulmonary trunk
Bulbus cordis -->
smooth parts of L and R ventricles
Primitive ventricle -->
trabeculated parts of L and R ventricles
Primitive atria -->
trabeculated L and R atria
Left horn of sinus venosus -->
coronary sinus
Right horn of sinus venosus -->
smooth part of R atrium
Right common cardinal vein and right anterior cardinal vein -->
During the period of organogenesis in fetal development, where does fetal erythropoiesis take place?
3-8 weeks: yolk sac
Between 6-30 weeks of development, where does fetal erythropoisis take place?
During which time of fetal development does erythropoiesis take place in the spleen?
9-28 weeks
When does the fetus start making red blood cells from its bone marrow?
28 weeks and onward
Fetal Hb has 2 alpha chains and:
2 gamma chains
Adult Hb has 2 alpha chains and:
1 beta chains
Umbilical vein -->
ligamentum teres
umbilical arteries -->
MEDIAL umbilical ligaments
ductus arteriosus -->
ligamentum arteriosum
ductus venosus -->
ligamentum venosum
foramen ovale -->
fossa ovalis
allantois - urachus -->
MEDIAN umbilical ligament
Urachus =
part of the allantoic duct between the bladder and the umbilicus
Baby takes first breath -->
lower pulmonary vasculature R --> raise LA P --> close foramen ovale
raise in O2 --> drop in prostaglandins --> close ductus arteriosus
Purpose of ductus venosus =
shunt O2-rich blood from umbilical vein to IVC, bypassing liver circulation
Purpose of foramen ovale =
shunt O2-rich blood arrived from IVC to left side of heart to be pumped out the AO and to the head
1st AO arch -->
part of maxillary artery
2nd AO arch -->
stapedial artery and hyoid artery
3rd AO arch -->
common carotid artery, proximal internal carotid artery
4th AO arch (left and right) -->
(left) AO arch
(right) proximal subclavian a.
6th AO arch -->
pulmonary arteries, ductus arteriosus (left side)
branchial clefts came from ecto/meso/endoderm?
branchial arches came from ecto/meso/endoderm?
mesoderm and neural crest (which is ectoderm)
branchial pouches came from ecto/meso/endoderm?
mandible, malleus, incus, sphenomandibular ligament came from:
branchial arch 1
muscles of mastication (temporalis, masseter, pterygoids) came from:
branchial arch 1
mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini, anterior 2/3 of tongue came from:
branchial arch 1
CN V2 and V3 came from:
branchial arch 1
stapes, styloid process, lesser horn of hyoid, stylohyoid ligament came from:
branchial arch 2
muscles of facial expression came from:
branchial arch 2
stapedius, stylohyoid, posterior belly of digastric came from:
branchial arch 2
CN VII came from:
branchial arch 2
CN IX came from:
branchial arch 3
greater horn of hyoid, stylopharyngeus muscle came from:
branchial arch 3
posterior 1/3 of tongue from:
branchial arches 3 + 4
4th branchial arch -->
most pharyngeal constrictors, cricothyroid, levator veli palatini, CN X superior laryngeal branch
branchial arch 6 -->
all intrinsic muscles of larynx, CN X recurrent laryngeal branch
sensation of anterior 2/3 of tongue provided by:
taste of anterior 2/3 of tongue provided by:
sensation and taste of posterior 1/3 of tongue provided by:
CN IX, extreme posterior CN X (branchial arche 3 & 4)
motor innervation of tongue:
taste is cranial nerves ??? which go to the ___ nucleus
CN VII, IX, X; solitary nucleus
tongue pain is sensed by cranial nerves ???
CN V3, IX, X
1 branchial cleft -->
external auditory meatus
eardrum, eustachian tube came from:
1st branchial membrane
branchial cyst in the neck is due to:
persistent cervical sinus, which are 2nd - 4th branchial clefts
1st branchial pouch -->
middle ear cavity, eustachian tube, mastoid air cells
2nd branchial pouch -->
epithelial lining of palatine tonsil
3rd branchial pouch -->
(doral wings) inferior parathyroid glands, (ventral wings) thymus!!!
4th branchial pouch -->
superior parathyroid glands
DiGeorge's syndrome...again:
abnormal development of 3rd and 4th branchial pouches --> T-cell deficiency and thymic aplasia and hypocalcemia
most common site of ectopic thyroid tissue:
foramen cecum =
normal remnant of thyroglossal duct
cleft lip due to:
failure of fusion of maxillary and medial nasal processes (formation of primary palate)
cleft palate due to:
failure of fusion of lateral palatine processes, nasal septum, and/or median palatine process (formation of 2ndary palate)
Diaphragm is derived from: (4)
1) septum transversum
2) pleuroperitoneal folds
3) body wall
4) dorsal mesentery of esophagus
diaphragm innervated by:
phrenic nerves (C3,4,5)
ventral pancreatic bud -->
1) pancreatic head
2) uncinate process
3) main pancreatic duct
pancreas is derived from:
foregut - supplied by celiac trunk
spleen is derived from:
mesoderm - arises from dorsal mesentery, but supplied by celiac trunk (via splenic artery)
annular pancreas is due to:
ventral and dorsal pancreatic buds abnormally encircle 2nd portion of duodenum
mesonephric/wolffian ducts -->
seminal vesicles, epididymis, ejactulatory duct, vas deferens
paramesonephric/mullerian ducts -->
fallopian tubes, uterus, part of vagina
What suppresses development of the mullerian duct system in males?
mullerian inhibiting substance
Increased androgen exposure to fetus may cause development of:
mesonephric ducts