Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/65

Click to flip

65 Cards in this Set

  • Front
  • Back
where do primordial germ cells originate from?
wall of yolk sac, and then migrate into gonad region
what are the different stages of female gametogenesis and when do they occur?
primary germ cell (46, 2N)--> primordial oognonia (46, 2N) --> primary oocytes (46, 4N) - where they remain arrested until puberty

--> primary oocyte completes meiosis 1 and forms a secondary oocyte (23, 2N) + 1st polar body --> secondary oocyte is arrested in metaphase II until fertilization

at fertilization: secondary oocyte completes meiosis II and forms a mature oocyte (23,1N) + 2nd polar body
what are the different stages of male gametogenesis and when do they occur?
primordial germ cells (46, 2N) --> type A spermatogonia (46, 2N, can undergo mitosis and provide a continuous supply of sperm throughout lifetime)

some type A --> type B spermatogonia (46, 2N), which enter meiosis I --> primary spermatocytes (46, 4N) --> secondary spermatocytes (23, 2N) --> 4 spermatids (23, 1N)
describe maturation process of spermatids
how long does it take?
spermatids --> spermatozoa
condensation of nucleus, formation of acrosome, formation of head, neck, adn tail)
takes 64 days
what is capacitation?
sperm can't fertilize an egg until they go through this process
unmasking of sperm glycosyltransferase and removal of proteins that coat the surface of the sperm
what are offspring at risk for if there is advanced Paternal age?
achondroplasia (retaded bone growth)
how does hte "morning after" pill work?
high doses of steroids that disrupt the endometrium so that implantation can't occur
what precaution must be taken if someone takes the mornign after pill?
steroids --> teratogenicity
if the pill doesn't work, therapeutic abortion recommended
what can be used to treat anovulatory cycle?
MOA
clomiphene citrate
it competes with estrogen at binding sites at the adenohypophysis, so it causes an increase in FSH/LH by suppressing the normal negative feedback
where does fertilization occur?
in the ampulla of the uterine tube
what are the steps of fertilization?
acrosomal reaction so sperm can penetrate the zona pellucida
--> cortical reaction so egg is not fertilized by more than 1 sperm
sperm and secondary oocyte membranes fuse adn sperm contents enter the cytoplasm of the egg
sprem genetic material --> male pronucleus and tail/mitochondria degenerate
secondary oocyte completes MII and forms a mature ovum. nucleus of ovum = female pronucleus
pronuclei fuse --> zygote!
what stages does the zygote go through following fertilization?
series of mitotic divisions
blastula (2 cells, then 4 cells, 8, 16) each cell is called a blastomere --> morula (32 cells) --> blastocyst
what is the structure of the morula?
inner cell mass and outer cell mass
at what stage is the zygote totipotent?
until the 8 cell stage
each blastomere can form an entire embryo by itself
how does the blastocyst form?
fluid is secreted within the morula, forming the blastocyst cavity
the outer cell mass becomes part of the placenta (trophoblast) and the inner cell mass becomes teh embryo
what does the trophoblast differentiate into?
syncytiotrophoblast
cytotrophoblast
what must happen in order for implantation to occur?
zona pellucida degeneration
where does the blastocyst implant?
within the posterior superior wall of the uterus, unless it's during the seretory phase of mentrual cycle, then it will implant in teh functional layer of the endometrium
describe the process of ectopic pregnancy
blastocyst implants in uterine tube d/t delayed transport `
what is the most common site for ectopic pregnance?
most common site for ectopic abdominal pregnancy
uterine tube
rectouterine pouch (pouch of douglass)
what predisposes ppl to ectopic pregnancy
endometriosis
PID
cause of dizygotc tiwns?
fertilization of 2 different eggs with 2 different sperm
cause of monozygotic twins
fertilization of 1 egg w 1 sperm
division of inner cell mass of blastocyst (embryoblast) in same placenta
cause of conjoined twins
embryoblast doesnt' entirely split
when does the embryoblast become bilaminar?
during week 2
what are the 2 layers the embryoblast divides into?
what does each become?
epiblast (--> amniotic sac)
hypoblast (--> yolk sac)
what is the future site of the mouth at week 2?
prochordal plate (the fusion of the epiblast and hypoblast cells)
describe the growth of syncytiotrophoblast?
continues growth into endometrium and makes contact wiht endometrial BV and glands
it doesn't divide mitotically
describe the growth of the cytotrophoblast?
primary chorionic villi protrude into syncytiotrophoblast
divides mitotically
what is the extraembryonic mesoderm?
new layer of cells derived from epiblast
--> connecting stalk and covers amnion
what forms the connecting stalk?
extraembryonic somatic mesoderm that lines the cytotrophoblast
what is the wall of the chorionic cavity called?
what does it consist of?
chorion
extraembryonic somatic mesoderm
cytotrophoblast
syncytiotrophoblast
what are the different types of extraembryonic mesoderm?
extraembryonic somatic mesoderm (--> connecting stalk)
extraembryonic visceral mesoderm (covers yolk sac)
where is hCG produced? what does hCG do?
syncytiotrophoblast
stimulates production of corpus luteum, which is necessary for progesterone production during the first 8 weeks of pregnancy
describe the source of progesterone in pregnancy?
made by the syncytiotrophoblast for the first 8 weeks, and then made by teh placenta for the remainder of the pregnancy
when can hCG be detected?
day 8 in blood and day 10 in urine
how long is hCG detectable for?
throughout pregnancy
pathogenesis of hydatidiform mole?
death of embryo, followed by hyperplastic proliferation of trophoblast --> vesicular or polycystic mass
what % of hydatidiform moles develops into gestational trophoblastic neoplasia?
3-5%
whhat adult cancer is associated with high CEA?
hihg AFP?
CRC
hepatoma, germ cell tumors
another name for RU-486?
mifepristone
MOA of RU 486
if implantation of conceptus has occurred, conceptus will be sloughed off along with endometrium
it blocks progesterone receptor
when does an embryo have a distinct human appearance?
by 8 weeks
how is cranio-caudal direction controlled?
Hox complex of genes
eaach contains 180 base pairs that encode 60AA long region that binds to DNA
what is gastrulation?
developing 3 germ layers
--> trilaminar embryonic disk (endoderm, ectoderm, mesoderm)
what is the first indication of gastrulation?
formation of primitive streak within epiblast
what do the neuroectoderm and neural crest cells arise from?
ectoderm
what are the different types of mesoderm that arise?
paraxial mesoderm
intermediate mesoderm
lateral mesoderm
what is sacrococcygeal teratoma?
remnant of primitive streak (which usually degenerates and disappears)
can contain bone, nerve, and hair because primitive streak is pluripotent
what is chordoma?
remnant of notocord, found either intracranially or in sacral region
occurs in men over 50
can be benign or malignant
where is the notocord?
what does it do?
mesoderm located between primitive node and prochordal plate
induces the formation of the neural tube
what are the components of the primitive streak?
primitive groove, pit and node
describe migration of epiblast cells
ectoderm
although, some epiblast cells displace the hypoblast cells --> endoderm and others tay midline and form mesoderm
what is caudal dysplasia?
constellation of syndromes ranging from minor lesions of lower vert --> complete fusion of lower limbs
caused by abnormal gastrulation (migration of mesoderm is disrupted)
what are the cranial anomolies associated with caudal dysplasia?
VATER
vertebral defects
anal atresia
TE fistula
renal defects

or... VACTERL
VATER + CV defects and upper limb defects
what embryonic event corresponds to 1st missed menstrual period?
week 3 of embryonic development
which period of embryonic development is most susceptable to teratogens?
embryonic period (3-8 weeks)
what are the components of the placenta and where do they originate from?
maternal component (portion of the endometrium called decidua basalis)
fetal component (tertiary chorionic villi, collectively called the villous chorion)
what does the maternal surface of the placenta look like in the afterbirth?
15-20 cotyledons that make it look cobblestoned
surface is dark red and oozes blood after birth (from torn maternal BV)
what does fetal surface of placenta look like in afterbirth?
chorionic BV, appearing smooth and shiny b/c of amnion covering
what is velamentous placenta?
occurs when umbilical vessels abnormally travel through amniochorionic membrane before reaching placenta proper
what is vasa previa
potential complication?
if mubilical vesssels cross internal os
one of hte BV could rupture --> fetus will bleed to death
what is placenta previa?
placenta is in lower part of uterus, covering internal os (instead of posterior superior wall of uterus)
uterine bv rupture in later part of pregnancy as uterus dilates
mother can bleed to death and fetus will have compromised blood supply
clinical presentation of placenta previa?
bright red vaginal bleeding
deliver by c-section b/c placenta blocks cervical opening
why does the mom not reject the placenta?
PGE2 inhibits t cells
also, no MHC on sycytiotrophoblast