Developmental Block A Flashcards
_____ million oogonia at 12 WGA
5
____ million primay oocytes at birth
2
development of chorionic sac occurs when?
end of second week
the core of a primary chorionic villi is
cytotrophoblasts
the core of a secondary chorionic villi is
mesenchyme
the mesenchyme core of a secondary chorionic villi will differentiate into ______, becoming a tertiary chorionic villi
capillaries and blood vessels
what makes up the chorion?
etraembryonic somatic mesoderm and the two layers of the trophoblast
decidual reaction-
cellular and vascular changes in the endometrium as the blastocyst implants
when does baby start to swallow amniotic fluid?
5th month
amniocentesis are done after ____ WGA
15
discordant twins-
shunted arterial blood from one twin through atriovenous anastomoses into venous circulation of other leads to one twin being underdeveloped
when does the primitive streak degenerate?
end of 4th week
intraembryonic mesoderm divides into what 3 layers?
paraxial, intermediate, and lateral mesoderm
paraxial mesoderm gives rise to what?
skeleton, striated muscle, dermis, and CT
intermediate mesoderm gives rise to what?
urogenital system
lateral mesoderm gives rise to what?
muscles of viscera, serous membranes, primordial heart, blood, spleen,
somite period between what days
20-30
how many somites at 20 days
1-4
how many somites at 30 days
35
intraembryonic coelom is developed in what week?
3rd
3 body cavities that the intraembryonic coelom will divide into
pericardial, pleural, and peritoneal
most nervous system cells will derive from
neural crest cells
neural tube formation begins in the ___ week of development
3rd
secondary neurulation-
secondary cavity formation at the caudal end of the neural tube to form the sacral spinal cord
what gives rise to the CNS?
neuroectoderm of the neural plate
Von Recklinghausen disease-
neurofibromatosis
CHARGE Syndrome stands for
Coloboma, Heart defects, Atresi choanae, retardation of growth and development, genitourinary problems, ear abnormalities
coloboma-
failure of choroid fissure to close
atresi choanae-
airway blockage
what kind of cells make up wall of neural tube
thick, pseudostratified columnar neuroepithelium
the spinal cord forms what 2 plates
alar and basal
sulcus limitans-
groove that separates the dorsal sensory neurons from the ventral motor neurons
when is cerebrospinal fluid produced
5th week
all NTDs are associated with
elevated alpha fetoprotein
somites differentiate into what 2 things?
dermomyotome and sclerotome
dermomyotome differentiates into what 2 things?
dermatome and myotome
myotome forms
myoblasts
sclerotome gives rise to
vertebrae and ribs
sonic hedgehog
causes the ventral part of somite to form sclerotome and express PAX1
PAX1
controls chondrogenesis and vertebral formation
PAX3
demarcates dermomyotome
PAX genes encode
nuclear transcription factors
sclerotomes have 2 parts:
cranial and caudal
cranial sclerotome portion is ______ arranged
loosely
sternum develops in what week?
6
four sources of tissue help develop limbs-
lateral plate mesoderm, somites, neural crest cells, and neural tube
ameila-
complete absence of limbs
meromelia-
partial absence of limbs
clavicle initially develops by ______
intramembranous ossification
cleidocranial dystosis-
incomplete or absent clavicles
achondroplasia is also called-
hypoplastic chondrodystrophy
achondroplasia is an impairment of-
cartilage development in epiphyseal plates
first heart field gives rise to
entire left ventricle and parts of both atria
second heart field gives rise to
entire right ventricle and outflow tracts and parts of both atria
sinus venosus will become what in the adult
sinus venarum, coronary sinus, and oblique vein of left atrium
3 veins that bring blood to the sinus venosus-
umbilical vein, vitelline veins, and cardinal veins
what do cardinal veins drain?
embryo proper
primitive atrium will become-
trabeculated part of atrias
primitive ventricle will become-
trabeculated part of ventricles
bulbos cordis will become-
smooth part of right and left ventricles
smooth part of right ventricle is called
conus arteriosus
smooth part of left ventricle is called
aortic vestibule
truncus arteriosus is the superior part of the
bulbos cordis
truncus arteriosus will become
aorta and pulmonary trunk
cardiac jelly signals endocardial cells to become
mesenchymal
the left horn of the sinus venosus fate-
degrades to become coronary sinus
the fate of the right horn of sinus venosus-
enlarges and becomes right half of right atrium
the right horn of the sinus venosus accounts for what two portions of the adult right atrial wall?
sinus venarum and auricle
double superior vena cava will result if
the left horn of sinus venosus fails to shrink
descending aorta gives off iliac arteries, which give off ________
umbilical arteries
after birth, umbilical vein becomes-
ligamentum teres hepatus
after birth, ductus venosus becomes-
ligamentum venosum
after birth, umbilical arteries are renamed _____
superior vesicle arteries that supply the bladder
distal portion of umbilical arteries becomes-
medial umbilical ligaments
tetralogy of fallot has what 4 defects?
pulmonary stenosis, ventricular septal defect, overriding aorta, and enlarged right ventricle
most common single cause of cyanotic heart disease in newborns
transposition of the great arteries
transposition of great arteries often is accompanied by _________, which makes it possible to survive birth and be surgically corrected.
septal defects or patent foramen ovale
which aortic arches will disappear?
first, second, fifth, and right side of sixth
3rd aortic arch will form
proximal aspect of common carotid and internal carotid artery
left 4th aortic arch will become what?
part of arch of aorta
right 4th aortic arch becomes what?
proximal portion of right subclavian artery
left 6th aortic arch becomes
part of pulmonary trunk and pulmonary arteries and the ductus arteriosus
which arches form laryngeal cartilages?
4th and 6th
time period of: pseudoglandular stage canalicular stage sacular stage alveolar stage
6-16 weeks
16-26 weeks
26 weeks to birth
32 weeks-8 years
all major elements of the lung have formed by the ______ stage
pseudoglandular stage
respiratory bronchioles develop in the ______ stage
canalicular
lung tissue becomes highly vascular in the _____ stage
canalicular
____% of alveoli develop postnatally
95
_______ treatment is given to mother who may be delivering prematurely to help speed baby’s lung development up
glucocorticoid
