Physiology - Female Pregnancy Flashcards
What are the three stages of labor and their durations?
First Stage (Dilation): From 3 cm to full dilation (~10 cm); lasts 8-10 hours (primiparous) or shorter (multiparous).
Second Stage (Fetal Expulsion): From full dilation to birth; duration varies.
Third Stage (Placental Delivery): From fetal expulsion to placental delivery; lasts 10-15 minutes.
What are the roles of progesterone and estrogen in parturition?
Progesterone: Hyperpolarizes myometrial cells, suppresses contractions, and inhibits PG synthesis.
Estrogen: Promotes myometrial contractions and counters progesterone effects.
What is the role of prostaglandins in parturition?
Prostaglandins increase intracellular Ca2+ in myometrial cells, stimulate uterine contractions, and cause cervical ripening and dilation.
What are the functions of oxytocin during and after parturition?
During Parturition: Stimulates uterine contractions.
Postpartum: Promotes lactation (milk ejection) and bonding behaviors.
Which hormones control lactation, and what are their roles?
Prolactin: Key hormone for milk production.
Oxytocin: Stimulates milk ejection from mammary glands.
Where and when does fertilization typically occur, and what is the lifespan of the ovum and sperm?
Location: Ampulla of the Fallopian tube.
Timing: Fertilization must occur within 12-24 hours after ovulation.
Lifespan: Ovum (~12-24 hours), Sperm (~72 hours in the female genital tract).
What is capacitation, and what happens during the acrosome reaction?
Capacitation: Activation process in the female genital tract, enabling sperm to penetrate the egg.
Acrosome Reaction: Sperm binds to the egg’s zona pellucida, leading to zona breakdown and membrane fusion.
How does the ovum prevent polyspermy after sperm fusion?
Membrane Depolarization: Prevents fusion with additional sperm.
Cortical Reaction: Hardens the zona pellucida, impairing further sperm binding.
What are the key maternal adaptations during pregnancy?
Increased cardiac output and renal blood flow.
Uterine enlargement and cervical changes.
Hormonal shifts (increased progesterone, estrogen, etc.).
What does ectoderm, mesoderm and endoderm form into?
What are the 2 parts of the placenta?
What are the maternal adaptation during pregnancy?
Why does milk production only start after delivery?
