11. Extra-Embryonic Membranes and Placental Development Flashcards
(21 cards)
What are the four extra-embryonic membranes in mammals, reptiles, and birds?
Chorion, Allantois, Yolk sac, Amnion
What is one function of extra-embryonic membranes?
Transfer area for nutrients and waste
Which extra-embryonic membrane provides physical protection to the embryo?
Amnion
Fill in the blank: The _______ regulates temperature for the embryo.
Amnion
What does the chorion develop from?
Trophectoderm
What type of placenta do placental mammals have?
Chorio-allantoic placenta
What type of placenta do marsupials have?
Chorio-vitelline placenta
In trophoblast differentiation, what are the two layers?
Cytotrophoblasts, Syncytiotrophoblasts
What is the role of syncytiotrophoblasts in the immune system?
Modulation of immune response
True or False: Syncytiotrophoblasts express MHC molecules recognized by the maternal immune system.
False
What hormone is produced by syncytiotrophoblasts to maintain pregnancy?
Human Chorionic Gonadotropin (hCG)
What is the primary function of trophoblast giant cells?
Invasive and promote blood vessel growth
What is a significant change in hormonal control during later pregnancy?
Luteo-placental shift
What are the three stages of chorionic villus development?
Primary villi, Secondary villi, Tertiary villi
What type of placenta is found in humans?
Discoid placenta
What materials transfer from mother to fetus?
- Nutrients
- Oxygen
- Water
- Immunoglobulins
What materials transfer from fetus to mother?
- Metabolic waste
- CO₂
- Heat
- Urea
- Uric acid
- Creatinine
Fill in the blank: The _______ is formed from amnioblasts and primitive ectoderm.
Amnion
What is the consequence of insufficient amniotic fluid?
Developmental defects
What is amniocentesis used for?
Sampling amniotic fluid for genetic testing
Describe the embryo folding process.
Embryo folds and twists, head and tail fold inward, sides fold inward, creating connection through umbilical cord
