Lecture 29: Female Reproductive System III

  1. Placenta
    • 1/4 is maternal-fetal interface
    • outermost cells of chorion laeve appose maternal decidua (3/4 interface)
    • Maternal surface: basal plate; lobules= cotyledons, spiral arteries
    • Fetal surface: beneath amnion is chorionic plate= layer of CT containing chorionic vessel (branced off umbilical vessels)
    • Arteries over veins
  2. Amnion
    • very thin, tensile strength
    • avascular
    • covers placenta (fetal side) and umbilical cord
  3. Chorion laeve (smooth chorion)
    • derived from outerlayer of blasocyst= trophoblast
    • multiple layer of trophoblast (cytotrophoblast)
    • outermost cells appose maternal decidua (3/4 interface)
    • Outer reflected fetal membrane
    • thin, avascular
  4. Placenta Villi
    • close but separate
    • bloods Villi extends from chorionic plate
    • Intervillous space- maternal blood, bathes outside of villi
    • branching of villi and fetal vessels inside of them
    • anchoring villi- attached to maternal decidua
    • Syncytiotrophoblast: no cell boundaries, come from fusion of cytotroph; bracnched microvilli
    • Cytotrophoblast: innermost, stem cell of the lining
    • macrophages
  5. Villi
    villi form all the way around, degenerate leaving multiple layers of cytotrophoblast = chorion laeve
  6. Placental barrier
    • Early (first trimester): syncytiotrophoblast, cytotrophoblast, mesenchyme, fetal endothelial cells
    • As placenta grow, less cytotroph
    • Late (third trimester): sycytiotrophoblast and endothelia cells
  7. Maternal vascular adaptation
    endovascular trophoblast invade spiral arteries, replace m, so can't react to vasoconstrictors, keeps wide open conduit of blood supply to placenta, prevetn hypertention
Card Set
Lecture 29: Female Reproductive System III
Female Reproductive System III