Repro 4 Flashcards
Peak Fertility is ages ______, which is not well matched to mottern pattern of delayed childbearing in wealthy countries
Female infertility _______ between ages 20-40
Change of sucessful fertilization is _____ per cycle 30-35
Pregnancy complications also _____ with age
Peak fertility: 18-25
Female infertility quadruples between ages 20-40
Chance of successful fertilization is 20% per cycle 30-35 yo
Pregnancy complications also increase with age
Fertilization: Step 1: Gamete Transport:
SPERM:
______ of sperm enter the vagina
_____ actually reach the _______ (the site of fertilization)
The sperm reach the ampulla within 5 minutes but can stay there for up to _____
What are some things that help sperm travel to the site of fertilization?
- vaginal secretions become more _____
- ______ within semen induce muscle contraction in the ____ and ___ to propel sperm forward
- seminal “____”: semen coagulates upon ejaculation
Step 1 of Fertilization: Gamete Transport:
SPERM:
- millions of sperm enter the vagina
- 50-100 actually reach the ampulla of oviduct (site of fertilization)
- Reach the ampulla within 5 minutes but retained for 24-48 hours
Helpers:
- vaginal secretions become more alkaline
- prostaglandins in semen induce muscle contraction in uterus to propel sperm forward
- seminal “plug”: semen coagulates upon ejaculation
Step 1 in Fertilization: Gamete Transport:
OOCYTE:
- only ___ oocyte is released from ovary into ____ cavity
- ______ cells help fimbrae “capture” oocyte and direct towards oviduct
Fertilization:
- usually occurs in the _____
- first stages of embryonic development occur - development of blastocyte
OOCYTE:
- only 1 oocyte is released from ovary into peritoneal cavity
- cumulus cells help fimbrae capture oocyte and direct towards oviduct
Fertilization:
- usually occurs in the ampulla
- first stages of embryonic development occur - development of blastocyte
Fertilization: Step 2: Sperm Penetration of Oocyte
“Sperm _______”
- final step of sperm maturation
- allows sperm to penetrate the zona ____ surrounding the oocyte
- involves removal of the _____
Fertilization Step 2: Penetration of Oocyte:
“Sperm capacitation”
- final step of sperm maturation
- allows sperm to penetrate the zona pellucida surrounding the oocyte
- involves removal of protective coat
Fertilization Step 2: Penetration of Oocyte:
Acrosomal Reaction:
- Sperm binds to _____ protein (glycoprotein) via surface receptors
- Triggers _______ in sperm cell, leading to exocytosis of _____ enzymes
- Sperm and oocyte membranes fuse—- acrosome reacted sperm bind to _____ proteins
Penetration of Oocyte:
Acrosomal Reaction:
- Sperm binds to ZP3 protein (glycoprotein) via surface receptors
- Triggers increased calcium in sperm cell, leading to exocytosis of hydrolytic enzymes
- Sperm and oocyte membranes fuse—acrosome reacted sperm binds to ZP2 proteins
Fertilization Step 2: Sperm Penetrating Oocyte:
Cortical Reaction:
- ______ mediated release of cortical granules
- Enzymes in these granules do what?
- Prevention of polyspermy: triploid cells are not viable of….
Sperm Penetrating Oocyte:
Cortical Reaction:
- Calcium-mediated release of cortical granules
- Enzymes in these granules prevent ZP3 and ZP2 binding
- Prevention of polyspermy: triploid cells are not viable of “hardening” z. pellucida
Meiosis Completes:
Decondensation of sperm DNA
Oocyte is released from ________ arrest and completes ______
Second polar body is extruded– oocyte has ____, ____ chromosomes
Meiosis Completes:
Decondensation of sperm DNA
oocyte is released from metaphase II arrest and completes meiosis II
Second polar body is extruded – oocyte has haploid, unduplicated chromosomes
Placental Formation:
Lacuna (which are______) make contact with ____
Cytrotrophoblasts ______ and invade the ______ to form the chorionic villus
Mature villus = fetal tissue _____ into maternal blood
Placental Formation:
Lacuna (fluid filled sacs in the syncytium) make contact with maternal blood vessels
Cytrotrophoblasts proliferate and invade the syncytiotrophoblast to form the chorionic villus
Mature villus = fetal tissue protruding into maternal blood
Placental Formation:
- vascular _____ at the site of implantation is critical for fetal life
- conversion from ____ to _____
- spiral arteries _____ in diameter: ___ perfusion of placenta
- failure to develop vasculature results in what?
Placental Formation:
- vascular remodeling at site of implantation is critical for fetal life
- conversion from high resistance low capacity >>>>> to low resistance and high volume vessels
- spiral arteries increase in diameter: increasing perfusion of the placenta
- failure to develop vasculature develops into relative placental ischemia
Pre-eclampsia Eclampsia: leading cause of maternal death in developed countries
Hallmark Symptoms?
Risk factors?
Pathophysiology:
- relative placental ischemia leads to oxidative ___ and endothelial cell _____
- damaged _____ release vasodilators and vasoconstrictors- resulting in?
- endothelial cell layer between platelets and basement membrane is breached—–thrombosis causes capillary leak leading to ____ and _____
Pre-eclampsia Eclampsia:
Hallmark Symptoms: HTN, edema, proteinuria
Risk factors: first pregnancy, T2DM, HTN, lots of pregnancies in succession
Pathophysiology:
- relative placental ischemia leads to oxidative stress and endothelial cell damage
- damaged endothelial cells release vasodilators and vasoconstrictors— worseing the hypoperfusion
- endothelial cell layer gets breached, leading to capillary leak and ultimately edema and proteinuria
Syncytiotrotrophs: Endocrine Function:
First hormone released is ____
- binds to ___ receptors on corpus leteum and keeps it viable
- is what pregnancy tests detect in urine
- is the cause of “morning sickness” in first trimester
- also stimulates fetal ____ cells and fetal ___
- _____ feedback on maternal HPG axis
Syncytritrotrophs: Endocrine Function:
First hormone released is hCG
- hCG binds to LH receptors on corpeus leteum and keeps it viable
- hCG is what pregnancy tests detect in urine
- hCG thought to cause “morning sickness”
- hCG stimulates fetal Lyedig cells and fetal adrenal cortex
- Negative feedback on maternal HPG axis
Syncytiotrophoblasts: Endocrine Function
Other than releasing hCG, the also release ___ or __
Simular to which two hormones?
Explain
Also release hPL or hCS
Simular to GH and prolactin
GH like:
- counter regulatory to insulin,
- mobilizes glucose for fetal use
- stimulates fetal IGF-1
Prolactin-like:
- stimulates mammary gland development
Pregnancy is a Insulin ____ State
____ and ____ also reduce insulin sensitivity in the mother
Pregnancy is an INSULIN RESISTANT state
Estrogen and progesterone in the mother also reduce insulin sensitivity in the mother
Gestational Diabetes:
Incidence is ____
Usually resolves by _____ , but 50% continue onto T2DM
Caused by anti-insulin effects of ___, ____, ____, and ____ (hormones)
Higher risk groups:
- woman > 25 yo
- family history of diabetes
- ethnic groups with high rates of diabetes
Gestational Diabetes:
- Incidence is 3-8% (up to 16% in native americans)
- Usually resolves by end of pregnancy, but 50% continue into T2DM
- Caused by anti-insulin effects of hPL, cortisoal, progesterone, and prolactin
- Higher risk groups
- women > 25 yo
- family history of diabetes
- ethnic groups with higher rates of T2DM
Functions of the placenta:
1.
2.
3.
Also plays the role of Lungs (gas exchange), gut (supplies nutrients), kidney, endocrine gland
Placental Functions
- Supportive : provides nutrients for fetal growth
- Immune: prevents rejection of fetus by mother
- Endocrine: synthesizes hormones
