reproductive: PREGNANCY Flashcards
when and where does spermatogenesis begin?
- begins at puberty
- occurs in seminiferous tubules
how spermatogenesis start at puberty ?
sex cords in testes develop a lumen that become seminiferous tubules
SOS #n #c in spermatogenisis and oogenesis with time period and stages :)))
A- 2n 2c diploid
-males: SPERMATOGONIA (at puberty)
-females: OOGONIA (divide in utero)
(both derived from primordial GERM CELLS)
—-—> DNA synthesis
B- 2n 4c diploid
-males: PRIMARY SPERMATOCYTES
-females: PRIMARY OOCYTE (arrest in meiosis I prophase until puberty)
———>meiosis I
C- 2 (1n 2c) haploid
-males: SECONDARY SPٍِERMATOCYTE
-females: a-SECONDARY OOCYTE (at menstrual cycle, note: other primary oocytes become polar bodies and degenerate)
—-—> meiosis II
MALES: 4 (1n 1c) haploid : SPERMATIDS: 4 haploid gametes result—> then: undergo SPERMIOGENESIS!!!
to form: sepermatozoa (sperm)
FEMALES:
no fertilization: oocyte degenerates (NO MEIOSIS II)
fertilization: COMPLETES MEIOSIS II to form OVUM 1 (1n 1c) haploid
what is spermiogenesis?
how is it done? 4 steps
formation of spermatozoa (from spermatids)
1-formation of ACROSOME: cap of sperm (contains enzymes to assist in fertilization)
2-condensation of nucleus
3-formation of neck and tail
4-shedding of most of cytoplasm
sertoli cells and leydig cells and spermatogonia
- location and function?
- how is it stimulated?
sertoli cells -line walls of seminefrous tubules -support/regulate spermatogenesis -stimulated by FSH leydig cells -interstitium (between tubules) -secrete testosterone -stimulated by LH spermatogonia -behind blood-testis barrier (separated from tubule by sertoli cells)
relation between sertoli cells and leydig cells in spermatogenesis
leydig cells release testesterone (stimulated by LH) which acts in a a PARACRINE manner to support sertoli cells (stimulated by FSH)
what cells form the BLOOD-TESTIS BARRIER? what type of junctions and why are they important? and describe both sides (apical/basal)
-sertoli cells
-tight junctions b/w adjacent sertoli cells
(isolate sperm, protection from autoimmune attack)
-apical side (toward tubule): meiosis and spermiogenesis
-basal side: spermatogonia cell division
what hormones are needed for normal spermatogenesis?
FSH, LH,….???
FSH
LH
function of placenta
1- nutrient
2- gas exchange
what is a decidual reaction
endometrium rxn at implantation
what are the 2 membranes that surround the fetus in utero?
1- AMNION (inner membrane)
holds amniotic fluid
2- CHORION (surrounds amnion/embryo)
derived from trophoblast
basal plate vs chorionic plate
of the placenta
basal plate (maternal side)
-includes maternal decidua basalis
chorionic plate (fetal side)
-give rise to chorionic villi
what layer of the blastocyst develops into placenta
outer layer: trophoblast
2 cell layers of trophoblast?
both together form what?
1- syncytiotrophoblast (outer)
- invades endometrium
- villi
- form lacunae (spaces) for maternal blood
2- cytotrophoblast (inner)
- proliferates, thus cells migrate into (1)
- secretes proteolytic enzymes to aid invasion
they form the chorionic villi
chorionic villi function and layers
contact area with maternal blood: digestive tract (nutrients) and resp organ (gas exchange)
- outer: syncytiotrophoblast
- inner: cytotrophoblast
how does the chorionic villi connect to the umbilical cord
fetal MESODERM invades villi,
branches of umbilical artery/vein grow :)
placental circulation
- maternal side
- fetal side
maternal
1- endometrial spiral arteries
2- villous space
3- endometrial vein
fetal
1-umbilical arteries (deoxy)
2- chorionic arteries
3- capillaries
4- capillaries
5- umbilical vein (oxy)
placental barrier
- oxygen co2?
- glucose?
- a.a?
- abs?
- diffusion
- facilitated
- active
- only IgG
umbilical cord is derived from mother or fetus? what parts ?
only FETUS
derived from:
1- yolk sac
2- allantois
what is the allantois?
what does it become?
what happens to it later?
- outpouching from wall of gut
- walls form umbilical blood vessels
- lumen occludes in development: become URACHUS: fibrous remnant: connects bladder to umbilicus
umbilical cord consists of
2 umbilcal arteries (deoxy)
1 umbilical vein (oxy)
-wharton jelly (contains mucopolysaccharides- similar to vitreous humor)
-allantoic duct (connects fetal bladder to umbilical cord) obliterates-urachus
what fetal anomalies are associated with single umbilical artery
1- aneuploidy
2- congenital malformations
what is a remnant of allantois ?
connects what?
becomes what?
may cause ?
urachus
- bladder and umbilical cord
- in adult: median umbilical ligament
- may cause ADENOCARCINOMA of bladder
urachus anomalies 3
1- patent urachus urine discharge from umbilicus 2- vesicourachal diverticulum diverticulum of bladder 3-urachal cyst partial obliteration fluid filled cavity —> infection risk
immunology of pregnancy
since fetus half genes are from the father (i.e HLA protein differ from mother) how is he protected? sosososo
by PLACENTA
1- trophoblast cells DO NOT EXPRESS MANY MHC CLASS I antigens
2- placenta secretions BLOCK IMMUNE response
dizygotics (fraternal twins) vs monzygotic (identical twins)
-dizygotic
2 zygotes (2 ova 2 sperms)
-monozygotic
1 zygote divides in 2 (1 ova 1 sperm)
more fetuses = shorter pregnancy, how many wks?
single:
twin:
triplets:
single: 40 wks
twin: 37 wks
triplets: 33 wks
what is more common when IVF is used ?
mono di
dizygotic twins
how many amnion/chorion is there in dizygotic twins?
DIchorionic DIamniotic
i.e 2 seperate placentas
how many amnion/chorion is there in monozygotic twins? explain
when can a woman get conjoined twins (time of division) :)
depends when zygote divides: -days 1-3 (MORULA) dichorionic diamniotic -days 4-8 (BLASTULA) monochorionic diamniotic -days 9-12 (IMPLANTED BLASTULA) monochorionic monoamniotic -days +13 (FORMED EMBRYONIC DISC) monochorionic monoamniotic (conjoined twins)
what are the increased risk of twin pregnancies ?
- fetus
- mother
fetus -growth restriction -congenital anomalies -preterm delievery mother -gestational hypertension/ preeclampsia
embryonic age vs gestational age
- embryonic age: age dated to FERTILIZATION
- gestational age: age dated to LMP (i.e embryonic age +2 weeks)
when (related to period) and where does fertilization happen?
- occurs within 1 day of ovulation
- ampulla of fallopian tube
when does implantation occur?
how is menstruation prevented (i.e maintained) ??
-6 days after ovulation —->for the 1st 10 wks: -syncytiotrophoblast secretes hCG which: 1- maintains CORPUS LUTEUM 2-CL continues PROGESTERONE release thus menstruation is prevented —->after 10 wks -placenta secretes hCG
why do we check BETA hCG and not ALPHA?
hCG has a and b
same alpha in: hCG, LH, FSH, TSH
describe the structure of hCG:
its similar to what hormone?
2 glycoprotein subunits (heterodimeric glycoprotein)
SIMILAR TO LH !!!!!
what type of test is used to detect pregnancy (using HCG)? what do they detect?
antibody based tests (ELISA variants)
-detect BETA subunit of hCG !!
- what is more sensitive serum or urine hCG test?
- when does each show positive result?
- serum tests are the MOST SENSITIVE ! (detect very low levels 1-2 mIU/mL) but urine has a threshhold of 20-50 mIU/mL
- serum: within 1 wk of conception
- urine: may not be positive until 2wks or more
what hormones are produced by the sycytiotrophoblast?
1- hCG
2- human placental lactogen (chorionic somatomammotropin) —> higher levels as placenta grows during pregnancy
what is the most important effect of human placental lactogen (protein hormone)?
BLOCKS EFFECTS OF INSULIN (useful for fetus)
1- raises blood glucose level
2- promotes breakdown of fatty acids by mother for fuel
3- promotes breakdown of proteins for fuel
remember that :
PREGNANCY is an INSULIN-RESISTANT STATE :))))))
i.e decreased maternal response to insulin
what happens to the diabetes of a pregnant diabetic women?
it is worsened
how do we screen for glucose in pregnant women and why? sos
SERUM GLUCOSE TESTING
because glycosuria occurs in normal pregnancy :) due to less absorption of glucose by the proximal tubules
i.e urine testing is NOT useful
list 5 physiological changes during pregnancy
1- total body volume expands 2- red cell mass expands 3- hemodynamics a- cardiac output rises b- peripheral resistance falls 4- hyper-coagulable state 5- ventilation increases
how does plasma volume (total body volume) expands during pregnancy?
blood fills placenta so mom increases renin to increase salt and water retention
what type of anemia is caused during pregnancy? explain
DILUTIONAL ANEMIA : mild asymptomatic
rise in volume»_space; rise in red cells
NOTE: there is a rise in red cell mass d/t increased maternal EPO
what happens to the cardiac output during pregnancy? what factors affect it? 3
CO increases
1- PRELOAD increases (BV increase)
2- AFTERLOAD decreases (SVR decrease)
3- maternal HR increases slightly
what is the mechanism that leads to a physiological DECREASE in BP in pregnant women??? sos
peripheral resistance falls
- (PLACENTA is a low resistance system)
- (maternal vasodilation)
i. e placenta has a PARALLEL (not SERIES) resistance with the mother so the total resistance decreases
when the placenta is removed, what happens to the peripheral resistance? what association that effect has on the heart?
peripheral resistance (for both mom baby) RISE
- increase left atrial pressure
- closes the foramen ovale
pregnant women with palpatations when laying down
diagnose? +mechanism
supine hypotension
LARGE BABY (later stages) compresses IVC when lying flat:
decreased venous return —> decreased preload —>decreased CO
note: symptoms are due to the response: REFLEX TACHYCARDIA
what clotting factors change during pregnancy 2 ? lead to what state?
1- increased fibrinogen
2- decreased protein S
HYPERCOAGUABLE STATE
what are the physiological pulmonary changes during pregnancy?
- ventilation ?
- tidal volume ?
- resp rate?
VENTILATION INCREASES
-more CO2 to exhale (baby metabolism)
d/t increased tidal volumes
-RR minimally changed
what are the 3 physiological changes that leads to labor?
1- regular uterine contractions
2- progressive dilation of cervix
3- descent and expulsion of fetus
what is preterm labor in wks ?
<37 wks
women develops uterine contractions very EARLY during pregnancy. tx?
Terbutaline/ Ritodrine
B2 agonists —> increase cAMP
thus relaxes uterine SMOOTH muscle
inhibiting contractions
what score is used to asses newborn immediately after birth?
what is the score out of?
at what times after birth?
what are the 5 factors ?
what is considered low score? at what time? leads to what dx?
-Apgar score
-10 points score
-at 1 and 5 min after birth
1-HR
2-Resp effort
3-muscle tone
4-reflex irritability
5-skin color (pink,blue)
-5min score = 3 , associated with NEUROLOGICAL damage (e.g cerebral palsy)