Lesson 4 Part 2 Placenta and Germ Layers | California State University, Northridge

University:
California State University, Northridge
Course:
BIOL 211 | Human Anatomy
Academic year:

2022
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282

Pages:

2
Author:

Nesbyenvkk

Part 2: Placenta and Germ Layers Q: Placenta forms from the ______ and the ______. A: Trophoblast (fetal part) and decidua basalis (maternal part). Q: The fetal part of the placenta (chorion) is made up of ______ ______, becoming highly branched structures containing blood vessels under the trophoblast area. A: Chorionic villi. Q: Villi protrude into large spaces known as the ____ in the ____. A: Lacunae; decidua basalis. Q: Maternal blood flows into the ____ and washes over the villi, allowing for the exchange of ____, ____ and blood gases between mother and fetus. A: Lacunae; nutrients, wastes. Q: Epiblast contributes to forming the _______________ and ___________. A: Amniotic membrane and amniotic cavity. Q: Hypoblast contributes to forming the _____. A: Yolk sac. Q: Morphological origin of the placenta: _____ and partly of maternal origin; arising from transformation of the ______. A: Chorionic villi (fetal); uterine mucosa. Q: Chorionic villi extend into the ______ in the decidua basalis. A: Intervillous spaces. Q: What is chorionic villi? A: Projections of the trophoblast that eventually contain blood-filled capillaries. Q: Do maternal and fetal blood vessels join or mix? A: No. Q: What substances diffuse across the placenta? A: O₂, nutrients, wastes. Q: What does the placenta store and produce? A: Nutrients and hormones (hCG). Q: Is the placenta a barrier to microorganisms? A: Yes, except some viruses (AIDS, measles, chickenpox, poliomyelitis, encephalitis). Q: Is the placenta a barrier to drugs such as alcohol? A: No. Q: When does the placenta fully form? A: During the 3rd month. Q: What happens to the placenta after the birth of the baby? A: It detaches from the uterus (afterbirth).