Physiology of Pregnancy (Part 2) скачать в хорошем качестве

Physiology of Pregnancy (Part 2)

Explore Implantation, Placenta, and Pregnancy Hormones with Dr. Faiza Walk through implantation, early trophoblast invasion, placental anatomy, fetomaternal exchange, and the key hormones of pregnancy. Clear explanations. Clinical links. Made for MBBS and PG learners. 🔬 Key Topics Covered: Implantation Basics: From free-floating blastocyst to complete embedding in endometrium. Trophoblast Invasion: Syncytiotrophoblast cords, loss of cell boundaries, lacunar development, and early chorionic villi. Why Fetal Graft Isn’t Rejected: Low classical MHC expression, non-polymorphic molecules, local immune modulation, and T-cell apoptosis concepts. Early Nutrition Timeline: Uterine/tubal secretions, decidualization, and shift to placental supply by 10–12 weeks. Placental Anatomy in Brief: Chorionic villi, maternal sinusoids, and umbilical vessels enabling bidirectional exchange. Gas Exchange Logic: PO₂ gradient (~20 mm Hg) vs lungs (~60 mm Hg), fetal Hb affinity advantage, higher fetal Hb concentration, and the double Bohr effect. CO₂ and Solute Transfer: Rapid CO₂ diffusion (high solubility), facilitated glucose transport, lipid transfer, amino acids, and fetal waste excretion to maternal blood. Hormone Overview: • hCG — sustains corpus luteum, supports early progesterone, early pregnancy detection, stimulates fetal testis. • Estrogen — uterine and breast growth, pelvic ligament relaxation, upregulates oxytocin receptors and gap junctions near term. • Progesterone — maintains pregnancy, reduces uterine contractility, cervical mucus plug, lobulo-alveolar breast development. • hPL/Chorionic Somatomammotropin — lowers maternal insulin sensitivity, spares glucose for fetus, promotes lipolysis. • Relaxin — softens cervix, relaxes pelvic ligaments, vasodilation. • PTHrP — mobilizes maternal calcium for fetal bone mineralization. Maternal Endocrine Changes: Pituitary (ACTH, TSH, prolactin↑; FSH/LH↓), adrenal steroids, aldosterone, thyroid hormones. Fetoplacental Unit: Cholesterol → pregnenolone/progesterone (placenta); fetal adrenal DHEA/DHEA-S → placental aromatization to estradiol/estriol. 🎓 Learning Objectives: Understand implantation and early placental development. Explain fetomaternal immune tolerance mechanisms. Trace nutrition shift from decidual to placental support. Apply the double Bohr effect to placental gas exchange. Differentiate roles of hCG, estrogen, progesterone, hPL, relaxin, and PTHrP. Describe the fetoplacental unit in steroidogenesis. 💡 Clinical Relevance: Interpret early pregnancy tests and hormone trends. Relate placental physiology to IUGR, GDM, and preeclampsia risk. Explain neonatal polycythemia or anemia via placental transfer dynamics. Link endocrine changes to timing of labor onset and postpartum adaptations. 💡 My personal stamp: concept clarity, clinical correlations, and exam-focused takeaways—so you learn once and remember always. 📚 Learning Resources (copy and paste as plain text): Phone: +92 310 7990649 Email: [email protected] Website: https://www.medicoseacademics.com/ Facebook:   / medicoseacademics   Instagram:   / medicoseacademics   YouTube:    / @medicoseacademics   Dr. Faiza Assistant Professor of Physiology MBBS (AIMC, lahore, Best Graduate) FCPS (Physiology) CHPE (Certificate in Health Professional Education) DHPE (Diploma in Health Professional Education) DHPE (Masters in Health Professional Education) MBA (Masters of Business Administration) MPH (Masters of Public Health) LinkedIn:   / faizaikram   Tags: Implantation, Placenta, Trophoblast, Syncytiotrophoblast, Decidualization, Placental Hormones, hCG, hPL, Estrogen, Progesterone, Relaxin, PTHrP, Double Bohr Effect, Fetal Hemoglobin, Fetoplacental Unit, Maternal Adaptations, Gas Exchange, Obstetrics, Embryology, Medical Physiology