1 / 30

Fetal Membranes & Placenta

Fetal Membranes & Placenta. Protection Nutrition Respiration Excretion Hormone. Chorion Amnion Yolk sac Allantois. Changes in the Trophoblast. By the beginning of the 2 nd month, trophoblast is characterized by a great number of 2° & 3° villi that give it a radial appearance.

kyrie
Télécharger la présentation

Fetal Membranes & Placenta

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fetal Membranes & Placenta Protection Nutrition Respiration Excretion Hormone Chorion Amnion Yolk sac Allantois

  2. Changes in the Trophoblast • By the beginning of the 2nd month, trophoblast is characterized by a great number of 2° & 3° villi that give it a radial appearance. • Chorionic plate • Outer cytotrophoblast shell • Lacunar or intervillous spaces • Syncytial knots –

  3. Chorion Frondosum &Decidua Basalis • Chorion frondosum (bushy or villous chorion) • Chorion laeve (smooth chorion) • Decidua basalis • Decidua capsularis • Decidua parietalis (decidua vera) • Placenta – • Amniochorionic membrane

  4. Structure of the Placenta • By the beginning of the 4th month, placenta has 2 components: • Fetal portion – • Maternal portion – • Chorionic & decidual plates • Junctional zone • Decidual septa & cotyledons

  5. Full-term Placenta • At full term, placenta is discoid with a diameter of 15~25 cm, is approximately 3 cm thick, & weighs about 500~600 g. • Maternal side – • Fetal surface –

  6. Circulation of the Placenta • The intervillous spaces of a mature placenta contain approximately 150 ml of blood, which is replenished about 3 or 4 times per minute. • Placental membrane / barrier (x) – – • Hemochorial type

  7. Function of the Placenta • Exchange of metabolic & gaseous products between maternal & fetal bloodstreams • Exchange of gases – • Exchange of nutrients & electrolytes – • Transmission of maternal antibodies – • Production of hormones –

  8. Amnion & Umbilical Cord • Primitive umbilical ring – • Primitive umbilical cord – • Physiological umbilical hernia • Jelly of Wharton

  9. Amniotic Fluid • The amniotic cavity is filled with a clear, watery fluid that is produced by amniotic cells but is derived primarily from maternal blood. • Amount – • Circulation – • Function–

  10. Fetal Membranes in Twins • Arrangement of fetal membranes in twins varies considerably, depending on the type of twins & on the time of separation of monozygotic twins.

  11. Dizygotic Twins

  12. Monozygotic Twins

  13. Frequency of Types of Placentas & Fetal Membranes in Monozygotic (MZ) & Dizygotic (DZ) Twins

  14. Conjoind (Siamese) twins

  15. Parturition (Birth) • Stage 1 : effacement & dilatation of cervix • Stage 2 : delivery of fetus • Stage 3 : delivery of placenta & fetal membranes

More Related