Fertilization, Pregnancy And Childbirth Flashcards
What is fertilization?
Fertilization occurs when a sperm cell binds to the zona pellucida surrounding the egg, triggering the acrosome reaction and the release of enzymes necessary for sperm penetration.
What is capacitation?
Capacitation is a process involving changes in membrane structure and function that enable sperm to penetrate the egg.
What is implantation?
Implantation involves a complex interplay between the blastocyst and the endometrial lining.
How do trophoblast cells interact with the endometrial lining?
Trophoblast cells of the blastocyst adhere to the endometrial epithelium through interactions mediated by integrins, selectins, and cell adhesion molecules.
What happens after trophoblast cells attach to the endometrium?
Upon attachment, trophoblast cells invade the endometrial stroma, facilitating the establishment of maternal-fetal circulation and the formation of the placenta.
What triggers the onset of labor?
The onset of labor is triggered by a cascade of hormonal and biochemical events, including the activation of the fetal hypothalamic-pituitary-adrenal (HPA) axis.
What role does cortisol play in labor?
Cortisol stimulates the production of prostaglandins and oxytocin receptors in the uterine myometrium, promoting uterine contractions and cervical ripening.
What is the role of oxytocin in labor?
Oxytocin stimulates uterine contractions by binding to oxytocin receptors on uterine smooth muscle cells, leading to the amplification of contractions.
How does oxytocin contribute to labor progression?
Oxytocin creates a positive feedback loop essential for labor progression.
