Slide Set 11 - Reproduction and Development Flashcards
Because of what 4 reasons should we care about reproduction?
- having a family
- preventing pregnancy
- preserving fertility
- preventing birth defects and diseases
The number of chemicals registered for commercial use now stands at _________ – a ___% increase since 1979.
80,000
30%
Through what products are we exposed to the chemicals registered for chemical use on a day to day basis?
- industrial releases
- contaminated food
- household products
- cosmetics
- food containers
- toys
- workplace
What are 3 results of this rise in exposure to chemicals?
- increase infertility rates
- decreased sperm counts
- higher rates of birth defects
Sperm counts among western men have ______ over the past 40 years.
halved
What 2 chemicals are commonly found in toys, food containers, and many other consumer products?
- phthalates
2. BPA
What chemical is used as a flame retardant in household furniture and electronics? What system do flame retardants disrupt in our body?
PBED
Endocrine system
The number of boys born with penis abnormalities and genital defects has increased by ____ in the past 2 decades.
200%
Boys have a higher incidence of what 5 syndromes?
- ADHD
- learning disabilities
- Tourett’s syndrome
- cerebral palsy
- dyslexia
boys are ___ times as likely to be autistic.
4
The quality of sperm is declining. ____% of the sperm produced by a healthy man is ___ damaged.
80%
DNA damaged
Damaged sperm have been linked to a ____% increase in testicular cancer.
300%
The chemical industry has developed more than 90,000 man-made chemicals in the last 6 years. 85% of them have never undergone testing for their impact on the human body
–
In what area of the world has the gender ratio skewed towards girls? What are these trends linked to?
Northern hemisphere (north of Arctic circle, Japan, USA)
Disruption in endocrine system due to chemicals
What are organochlorines? 3 types
synthetic organic compounds with chlorinated aromatic molecules
- Industrial compounds (PCBs)
- Combustion Products
- Pesticides (DDT)
Despite worldwide treaty to ban or restrict use of Persistent Organic Pollutants (POPs), there has been a continued use of DDT to combat _______ in certain countries.
malaria
What are 3 characteristic of organochlorines?
- liposoluble
- bioaccumulate
- biomagnify
In what 4 ways do organochlorines disrupt the endocrine system? Give examples for each
- estrogen receptor agonists (PCBs, DDTs, and other insecticides)
- Bind androgen receptors/prevent androgen synthesis (DDE)
- Bind the aryl hydrocarbon receptor - modulate estrogen-dependent transcription (dioxins, PCBs)
- Bind thyroid hormone binding protein (hydroxylated aromatics)
________ ecosystems contain unusually high levels of environmental contaminants
northern
Organochlorines __________ in the arctic food chain
bioaccumulate (fatty fish, marine mammals, polar bears, birds, etc)
Inuit (Indigenous people of norther CAD) consume ___ times more PCBs than the general public.
40
Where in the body of Inuit mothers are there elevated amounts of organochlorines?
blood and breast milk (4.2 ng/mL)
How can maternal consumption of PCB-contaminated fish during pregnancy affect the baby?
- retarded gestational development
- low birth weights
- small head circumference
- neurodevelopment delays
- weaker immune system
Structure of the uterus:
What are its 2 main parts?
Pear-shaped
the crevix and the body
What is ectopic pregnancy?
development of the fetus in a place other than the uterus - 95% in the Fallopian tubes
What do ovarian follicles contain?
The developing oocyte
What is oogenesis?
process that results in formation of a mature egg
What are the ovaries?
endocrine organs that secrete the female sex hormones
What are the 2 female sex horomones?
estrogen and progesterone
What are the 3 divisions of a uterine tube?
- isthmus
- ampulla
- infundibulum
Where does fertilization usually occur?
at the AI junction
Function of oviducts/uterine tubes:
transport channels for ova and site for fertilization
If someone has a pelvic inflammatory disease, what happens if a pelvic infection occurs in the uterine tubes?
block passage, scar tissue, pus outside the tube can spread the infection to other organs
A pelvic infections happen as as a result of what fraction of ectopic pregnancies?
1/4
What are side effects of pelvic infections/pelvic inflammatory disease?
- pain upon palpation (physical examination of uterus)
- discharge
- fever
- pelvic discomfort
What happens during menstruation? How long does it last?
Spongy uterine wall breaks down, the degenerating tissue, blood, and unfertilized egg are passed out as central flow
4-7 days
What happens during the follicular stage?
(Stage leading up to ovulation) – FSH stimulates a follicle to mature and produce estrogen
During the follicular stage, estrogen promotes ________ of the uterine lining to support an embryo in case fertilization occurs
thickening
what happens during ovulation?
the mature egg is released from the follicle
During ovulation, what do estrogen and inhibin instruct the pituitary gland to do?
inhibit FSH and release LH (luteinizing hormone)
What is the main action that induces ovulation?
A spike in LH
What blocks the LH surge and ovulation?
constantly high levels of estrogen
What happens at the corpus lute stage?
(Stage after ovulation and before menstruation - the Luteal Phase) The corpus luteum forms from the ruptured follicle
During the Luteal Phase - What does LH (luteinizing hormone) from the pituitary stimulate the corpus luteum to produce?
progesterone and estrogen
During the Luteal Phase -Progesterone and estrogen promote _________ of the uterus in preparation for implantation of the fertilized egg.
vascularization
How long does the luteal phase last?
12-15 days
What does the developing placenta produce if fertilization occurs?
hCG
What does hCG do?
It acts to maintain the corpus luteum by binding to LH receptors on corpus luteum which promotes progesterone synthesis and further ensures that the uterine call is thickened so that embryonic development can occur and pregnancy can continue
The development of the placenta takes over the production of what?
estrogen and progesterone
What 3 things happen if fertilization did not occur?
- E & P decrease
- Endometrail tissue breaks down
- E and P block on hypothalamus is removed and cycle resumes
What happens to follicles in patients with polycystic ovarian disease?
follicles develop but do not ovulate
What 7 things happen to people with polycystic ovarian disease?
- highly irregular cycles
- cystic follicles
- elevated testosterone
- abnormal FSH, LH
- facial hair
- abdominal weight gain
What are the 2 diagnoses for polycystic ovarian disease? 2 treatments?
- blood test
- ultra sound
____ - pill
- surgery
- diet
What is a unique characteristic of polycystic ovarian disease?
- excessive conversion of T to DHT
What are the 2 types of birth control pills?
- combined pill
2. minipill
What is the combined pill made up of?
synthetic estrogen and progestin
What does the minipill contain?
only progestin
Why are synthetic hormone s used for birth control instead of natural hormones?
because our liver breaks down natural hormones really quickly
How does birth control work?
provides constant levels of E and P which inhibit LH and prevent ovulation. Progesterone thickens the mucus around the cervix
What do birth control implants release? How long does it last?
Progestin - 3 years
What does the birth control patch release? How often do you need to change it?
E and P
once/week
What is the doubling time of testicular cancer?
10-30 days
When is the testicular self exam best preformed?
after a warm bath or shower
What is Bisphenol A used to make?
a rigid transluscent polycarbonate plastic (triangle with a 7 in the middle)
How does BPA play a role in canned foods and drinks?
BPA-resin liners stop the contents from eroding the metal container
What hormone in the human body does BPA mimic?
estrogen!!!
What can long term exposure of BPA lead to in humans?
- infertility
- early puberty
- even breast and prostate cancers
Bisphenol A is found in human blood at what range?
0.2-9.2 ng/mL
where in the human body can BPA be found?
breastmilk
What is the mechanism of action of BPA in our body?
- Activates non-classical membrane-bound estrogen receptors
- high affinity to estrogen related receptors
- low affinity binding to ER-alpha and ER-beta
Fertilization most often occurs where?
outer 1/3 of the oviduct
how long does it take for sperm to reach the ampulla?
5-10 minutes
What is transport of the sperm aided by?
- mucosal secretion
2. prostaglandins in the seminal fluid from prostate which stimulate contractions of the uterus
How many sperm reach the ampulla?
several thousand
What must the cell do in order to successfully fertilize the ovum?
penetrate corona radiate (granulose cells), then bind and penetrate the zone pellucida
What does the sperm release once it binds to the zona pellucida? What does this permit?
acrosomal contents - proteases. This permits its entry into the perivitelline space then egg
How is the egg activated?
By calcium levels which rapidly rise and stimulate Phospholipase C
What does the block of polyspermy involve?
Changes to the zone pellucida to prevent other sperm from entering the egg
The risk of _______ increases as a woman ages.
aneuploidy (presence of abnormal number of chromosomes in a cell)
What is the most common cause of miscarriage?
aneuploidy
Of 1500 first trimester miscarriages ___% have abnormal chromosome (aneuploidy)
61
___% of embryos in humans miscarry after implantation
31
How long does it take for the zygote to travel to the uterus after fertilization?
3-5 days
What cellular component aids the zygote travel to the uterus?
cilia
What is a sperm cell called once it enters the uterus?
blastocysts
Rapidly increasing ______ from _______ binds receptors on the smooth muscle cells of the Fallopian tubes. What does this cause and allow?
P, CL
This causes a relaxing effect promoting entry of the egg into the uterus
When does prenatal period begin and end?
begins with conception and continues until the birth of the child
What must happen in order for implantation of the blastocysts to occur?
the developing embryo must reach the uterus and become implanted into the uterine lining.
How many days pass from fertilization until implantation in uterine lining?
5-7
When can hCg 1st be detected?
20-22 days
What might be a side affect of implantation?
spotting
What does the placenta do?
it anchors fetus to uterus and provides a “bridge” for exchange of nutrients and waste products between mother and baby
The placenta acts as what 3 glands for the fetus?
excretory
respiratory
endocrine
