Q1-intro, ovul, fert, implant, and embryonic period Flashcards
what is the leading cause of infant mortality
birth defects
what are characteristics of fetal alcohol syndrome
thin upper lip, small mid face, short palpebral fissures, flat philtrum
what occurs during early development phase
fertilization, implantation, gastrulation, formation of placenta, determination of body axes
what occurs during embryonic period (broad)
formation of major organs and systems
define epigenetics
heritable changes in gene expression
define genetic imprinting
only one allele expressed in parent specific manner
what disorder occurs when the maternal genes on critical region of long arm of chromosome 15 are deleted
angelman’s syndrome
what disorder occurs when the paternal genes in the critical region of the long arm of chromosome 15 are deleted
prader-willi
what disorder occurs when a piece of chromosome 5 is missing
Cri-du-chat syndrome
what are errors in genetic programming/tissues
malformation
what occurs when genetically normal tissues forced into abnormal shaped by mechanical/environmental forces
deformations
what happens when already formed tissues experience a specific insult
disruptions
what happens when one anomaly leads to another
sequence
what is the predominant cause of down syndrome
when nondisjunction occurs in female gametes
what is the predominant cause of Turner’s syndrome
nondisjunction of male gametes
where does oogenesis occur
cortex of ovary
when does the first meiotic division of oogenesis begin
12th fetal week
what is the likely diagnosis for someone who has mental retardation, craniofacial abnormalities, epicentral folds and flat face?
trisomy 21
what is the likely diagnosis for someone who has intellectual disability, congenital heart defects, low set ears and flexion of fingers
trisomy 18
what is the likely diagnosis for someone who has intellectual disability, holoprosencephaly, congenital heart defects, deafness, cleft lip and palate?
trisomy 13
Name this stage of mitosis: chromosomes contrast and condense; chromatids begin to join by the centromere
prophase
name this stage of mitosis: chromatids become distinguishable
prometaphase
name this stage of mitosis: chromosomes line up at the equatorial plate and doubled structure is evident (mitotic spindles are present)
metaphase
name this stage of mitosis: centromere divides followed by migration of chromatids of to opposite poles of the spindle
anaphase
name this stage of mitosis: chromosomes uncoil and lengthen, nuclear envelope reforms and cytoplasm divides
telophase
define primordial follicle
primary oocyte + follicular cells
_______ are spermatogonia that undergo a limited number of mitotic divisions
Type A spermatogonia
______ are spermatogonia that undergo division to form primary spermatocytes
type B spermatogonia
what do theca internal cells secrete and what is it converted into (and by who)
secrete androstenedione and is converted to estrogen by granulosa cells
what do theca externa cells do
they are fibroblasts that form part of the stroma of the ovary
what happens to the egg after ovulation if it does NOT get fertilized
it will die and become the corpus albicans
what is the zone pellucida created by (the interaction between what?)
interaction between primary oocyte and granulosa cell
what type of follicle immediately precedes ovulation
graafian follicle
where does fertilization typically occur
ampulla of uterine tube
________ is a reaction that removes glycoproteins from the plasma membrane that is overlying the acrosome (making sperm fertile)
capacitation
what reaction must occur for sperm to get through the zone pellucida
acrosome reaction
what reaction occurs in order to prevent polyspermy, in which a calcium wave spreads out
cortical reaction
what reaction occurs by the occyte when it releases cortical granules making the zone pellucid impenetrable
zona reaction
what day does the morula form
day 3
where does the trophoblast come from
cells of the blastocyst wall (
what does the trophoblast form
fetal membranes and the placenta
where do embryonic stem cells typically reside
inner cell mass
what maintains the uterus in the secretory phase during implantation
progesterone and estrogen that is secreted by the corpus luteum
define hydatiform mole
trophoblast with only paternal genes that secretes high levels of hCG (that comes from the syncytiotrophoblast)
what is the most common location for an abdominal ectopic pregnancy
rectouterine cavity (pouch of douglas)
_____ is when the placenta covers the internal os
placenta previa
______ is when the placenta grows through the endometrium to the myometrium
placenta accreta
______ is when the placenta grows into the myometrium
placenta increta
_______ is when the placenta grows into the perimetrium
placenta percreta
________ is when the placenta separates partially or totally from the uterine wall
placenta abruptio
what does the trophoblast differentiate into
cytotrophoblast and syncytiotrophoblast
what does the inner cell mass differentiate into
epiblast and hypoblast
what does the amniotic cavity grow within
epiblast
hypoblast is______ while the epiblast is _______
ventral; dorsal
what day does the lacunae form in the syncytiotrophoblast
day 9
when do maternal blood vessels enlarge into sinusoids
9th day
what cells form the primitive yolk sac
hypoblast cells
what occurs in order for uteroplacental circulation to occur and on what day
sinusoids and lacunae fuse on day 11-12
where does the extra embryonic mesoderm form
between inner surface of cytotrophoblast and outer surface of primitive yolk sac
when does the primitive yolk sac diminish
after the large chorionic cavity forms within the splanchnic and somatic layers of the extra embryonic mesoderm
what day does the cytotrophoblast form villi
13th day
when does the secondary (definitive) yolk sac begin
on day 13 when the hypoblast cells migrate along the exocoelomic cavity
what 2 cavities are formed during the “week of 2s”
amniotic cavity and yolk sac
what secretes gonadotrophins
anterior lobe of the pituitary gland
what surge at the middle of the cycle leads to ovulation
LH surge
what type of cell do granulosa cells become after ovulation
lutein cells
what are the stages that the endometrium goes through
follicular, secretory/progestional and menstrual
what type of pregnancy is it when the blastocyst develops in the ovary proper
primary ovary pregnancy
what 2 layers does the embryoblast divide into
epiblast and hypoblast
_____ occurs when the forebrain is small, 2 lateral ventricles are merged into single ventricle and eyes are close together (hypotelorism)
holoprosencephaly
_____occurs when there is insufficient mesoderm t is formed in the caudal-most region of the embryo (hypoplasia and fusion of lower limbs, vertebral abnormalities, renal a genesis, imperforate anus, abnormal genitalia)
caudal dysgenesis (sirenomelia)
____ occurs when remnants of the primitive streak persist in the sacrococcygeal region and contain all 3 germ layers
sacrococcygeal teratomas
______ occurs when the positioning of all organs is reversed in a mirror image
situs inversus
______ occurs when there is discordant organ positioning with respect to symmetry with at least one organ (lateral defects because of failure to properly establish L-R axis) and have higher risk of midline malformations and congenital heart failure
situs ambiguous or heterotaxy
______ occurs when the neural tube fails to close in the cranial region and most of the brain fails to form
anencephaly
______ occurs when there are abnormally dense collections of capillary blood vessels that form most common tumors in babies; facial lesions may be focal or diffuse)
capillary hemangioma
what genes form the anterior-posterior body axis prior to and during gastrulation
Homeobox or HOX
what end of the embryo to epiblast cells migrate through the primitive streak
caudal
what is the first thing the mesodermal cells go through the primitive streak to form
notochordal process (then the plate in the midline of the cranial end of the embryo)
when does the notochordal plate become the notochord
when it detaches form the endoderm
what does the notochord develop into?
Nucleus pulposus
define vasculogenesis
blood vessels form from blood islands
what induces mesoderm cells to form hemangioblasts in vasculogenesis?
FGF2
what induces hemangioblasts to form blood cells in the center of the island and peripheral vessels
VEGF
what is the formation of blood vessels sprouting from blood vessels
angiogenesis
what is the main stimulator in the proliferation of endothelial cells that line vessels (in angiogenesis)
VEGF
when does the capillary system become established in the embryo?
when the heart begins to beat
what is the order of neurulation?
ectoderm dorsal to notochord forms a crest, then a plate, then a groove, then the neural tube
what gives rise to the CNS
neural tube
when does cranial closure of the neural fold at the cranial end occur
day 25
when does caudal closure of the neural fold occur
day 28
what disorder involves the vertebral arch missing, no neural protrusions and tufts of hair associated with the skin
SB occulta
what disorder involves meninges protruding out of the NT
SB meningiocoele
what disorder involves the spinal cord and meninges protruding out of the NT
SB myelomeningiocoele
how do neural crest cells migrate
laterally away from the neural tube
what gives rise to the PNS
neural crest
what gives rise to the anterior pituitary gland
surface ectoderm
what gives rise to the posterior pituitary gland
neural tube
what disorder is a congenital anomaly of an a ganglionic segment of intestine due to the neural crest cells inability to colonize the colon?
Hirschsprung’s disease
what gradients ventralize the mesoderm to form the intermediate and lateral plate mesoderm
BMP and Wnt
what does the paraxial mesoderm give rise to
notochord and somites
what do the ventral and medial walls of somites form
sclerotomes
what do sclerotomes form
axial bone and cartilage (and CT of limbs)
what cells form myotome
dorsomedial and ventrolateral cells
what does myotome split into
epaxial (back) and hypaxial (lateral and ventral body wall) muscles
what does lateral plate mesoderm split into
somatic (parietal) and splanchnic (visceral) mesoderm
what is splanchnic mesoderm associated with
endoderm
what is somatic mesoderm associated with
ectoderm
what does the intermediate mesoderm give rise to
excretory ducts of urinary system and gonads
