Final Exam Flashcards
Conception and fertilization can be defined as the fusion of _____to form a _____.
gametes; zygote
What stages are the oogonium, primary oocyte, and secondary oocytes locked in?
Oogenium is just granulosa cells, primary is locked in prophase 1, secondary is locked in metaphase 2.
What are spermatids the result of?
Secondary spermatocytes and meiosis II
What is nondisjunction?
Improper chromosome separation during anaphase due to improper spindle attachment.
Describe Robertsonian translocation.
The whole of a chromosome is joined end-to-end with another.
Male factor infertility relates to issues with ____, ____, and ____ of sperm.
production; function; delivery
Female factor infertility relates to _______ disorders, _____ obstruction, and ________ anomalies.
ovulatory; tubal; and uterine
Endometriosis is a progressive, malignant, inflammatory, and chronic condition in which endometrial tissue develops outside the uterus (T/F).
False! It is benign not malignant.
In endometriosis, how does the invading tissue behave?
It thickens, breaks down, and bleeds as well with each cycle.
Name the three main types of endometriosis.
Peritoneal, ovarian, and deep-infiltration.
PCOS is a reproductive circulatory disorder (T/F).
False, endocrine.
There is no one accepted definition of PCOS, but what are some key characteristics?
Hyperandrogenemia, hyperandrogenism, oligoanovulation, and polycystic ovaries.
What are some coocurrences of PCOS?
Diabetes, Cardiovascular Disease, Infertility, and Mood/Eating Disorders
Which androgens are most elevated in PCOS
Testosterone (total and free) and DHEA-S produced by ovaries and adrenal gland.
How do cysts form in PCOS?
Hyperandrogenism, hyperinsulinemia, and changes to paracrine signalling alter follicle growth. So… cystic follicles.
How does PCOS affect the HPO axis?
Increased luteinizing hormone (LH) and decreased follicle stimulating hormone (FSH)
How are sperm harvested for ARF?
Sperm is collected and evaluated for count, motility, progression, volume, viscousity.
Centrifuged to separate the parts and then motile sperm are resuspended in liquid media.
How are oocytes harvested in ARF?
Ovaries are stimulated, cycle and pituitary are suppressed. Ovulation is triggered and oocytes are collected.
Intrauterine Insemination (IUI) is primarily indicated with ______ infertility, donor sperm, and altered ovulation.
male-factor
How is ICSI different from IVF?
Instead of co-culturing the oocyte and sperm, a sperm is directly injected into an egg.
What are seminiferous tubules?
Where sperm production occurs, they are kept separate from circulation by the blood-testis barrier (Sertoli cells).
What are Sertoli and Leydig cells?
Sertolis are “nurse” cells part of the seminiferous tubule that help with spermatogenesis.
Leydigs are in the tubule wall and produce testosterone once puberty happens.
Which hormones stimulate spermatogenesis?
LH and FSH, testosterone and inhibin do the negative feedback on receptors in the brain.
What is the initial diploid cell that does mitosis to form primary spermatocytes?
Spermatogonia. Meiosis gives 2 secondary spermatocytes then 4 spermatids. Differentiation creates sperm.
What is spermiation?
Breakdown of Sertoli junctions and release of sperm from seminiferous tubules, to rete testes which concentrate it, then epididymis.
Spermatogenesis takes about 90 days (T/F).
False, 70!
What is capacitation?
Process in the female repro tract wherein cholesterol and glycoproteins are removed from the sperm head. Now, it can bind to the zona pellucida of the ovum.
Rates of infertility are lower in less industrialized countries (T/F).
False, more!
How is chromatin organization different in sperm than oocytes?
Sperm DNA is tightly packed, oocytes have less methylation and more loose chromatin.
Sperm histones are mostly replaced with protamines.
How are protamines different from histones?
They wrap around DNA more tightly, but they still go through post-translational modification (phosphorylation).
How are oocytes formed in utero?
Primordial germ cells colonize the cortex of the primordial gonad and replicate to 7 mil by 20 weeks. Primary oocytes are the leftover 2 mil that survive after this. Atresia in childhood leaves 40k eggs at puberty.
What are granulosa cells and theca folliculi?
Pre-antral stage: Granulosa cells secrete glycoproteins to form zona pellucida around primary oocyte. Theca folliculi is specialized connective tissue responsive to LH.
In the antral stage of oogenesis, fluid fills space between granulosa cells to form the central ______ and _____ follicles.
antrum; secondary
Where does the first polar body come from?
Primary oocyte. It will divide into two polar bodies. The secondary oocyte will divide into one mature ovum and one more polar body.
A Graffian follicle is the mature ovum follicle (T/F).
True, the wall is weaker and contractions will release the ovum out.
What is the corpus luteum?
Formed when the follicle wall collapses, it’s the endocrine organ during pregnancy.
How does the fertilized egg get to the uterine wall?
Peristaltic movements of the fallopian tube move it to the posterior uterine wall.
What are the three key events of the sperm-egg fusion process?
Attachment: Protein-protein or protein-carbohydrate mediated.
Membrane apposition: Hinge motion draws the membranes together.
Lipid mixing: Cytoplasmic continuity.
What stops a second sperm from entering the egg?
Fast block is an instant ionization (Ca+ influx). Cortical reaction (zonal inhibiting proteins and mucopolysaccharide release by cortical granules). Impenetrable fertilization barrier, zona pellucida gets thick.
Neural tube defects occur very early in pregnancy (T/F).
True
What are the two most common neural tube defects?
Anencephaly (open brain) and Spina bifida (closure of spinal cord)
Folate is the _____ name for vitamin B9, whereas folic acid is the _______ manmade version.
generic; oxidized monoglutamate
How is folic acid absorbed?
Hydrolyzed to monoglutamate in the gut then active transport across mucosa. Dihydrofolate reductase reduces to THF.
What is the main form of folate in plasma?
5-methyl-THF
Colonic microbiota synthesize folate (T/F).
True
Name 3 functions of folate.
Purine and thymidine synthesis
Methyl donation
Homocysteine —> Methionine conversion in SAM synthesis. Important for methylation.
About 2/3 of NTD can be prevented by increasing _____ intake at the beginning of pregnancy.
folate
What are high homocysteine levels a risk factor for?
Heart disease and stroke in the mother, and maybe baby.
Folate has no role in placental development (T/F).
False!!! Basically in everything (EVT invasion, angiogenesis, MMP secretion)
What are the three folate receptors in the placenta?
Folate receptor (FOLR A and B)
Reduced folate carrier (RFC)
Proton-coupled folate transporter (PCFT)
Which folate receptor shows greater expression in pregnancies complicated with birth defects?
PCFT as an adaptive response
How does folic acid uptake differ with gestational diabetes?
Leptin and TNF-a downregulate folic acid uptake. GDM modulates uptake by placental cells by increasing PCFT expression.
Which folate receptor is implicated in IFGR?
RFC
In preterm babies, which folate receptor is less expressed?
FOLR1
Maternal folate deficiency decreases ____ signalling.
mTOR
What is placental abruption?
When placenta separates from the wall before birth. Folic acid helps prevent this.
What has low paternal folate been shown to cause?
Low placental weight, and birth defects in mice
What are some foods that interact negatively with folic acid?
Alcohol, chocolate, tea.
What are three risks of too much folate?
Cancer, allergy, and undetected B12 deficiency.
What are the roles of Choline, B12, and B6?
Choline is a source of methyl groups + needed to synthesize phospholipids
B12 is important for methionine synthase and homocysteine conversion
B6 does a lot. Protein metabolism + cognitive development.
The placenta, fetus, and amniotic fluid account for ____% of the total pregnancy weight gain.
35
What is the role of Vitamin A in pregnancy?
Sperm production, normal reproductive cycles. For fetuses, HPA and organ development. Low Vitamin A can have consequences in early childhood too.
What is xerophthalmia?
Result of vitamin A deficiency, which also can cause increased maternal/infant mortality, anemia, and slow growth.