Placenta & Obstetrics

Question 1

Which surface of the placenta is the fetal surface & which surface is the materal surface?

Answer 1

• Top: fetal surface
  
  • tan/blue & glistening
  • should not smell foul
• Bottom: maternal surface
  
  • red, spondy w/ cotyledons (chorionic villi)

Question 2

Is this an early or term placenta? How do you know?

Answer 2

Early Placenta

• Not as much branching
• Don’t have chorionic villi
• syncytotrophoblasts (far right, labeled S)
• mesenchyme in the center
• not highly vascularized

Question 3

Is this an early or term placenta? How do you know?

Answer 3

• smaller villi (b/c branching)
• well vascularized
  
  • capillaries w/ fetal blood & lumen w/ maternal blood

Question 4

How can you determine the relative ages of the placental villi shown in the provided images?

Answer 4

taken at same magnification

• Left
  
  • 1st trimester
  • large
  • occasional blood vessel
• Right
  
  • 3rd trimester
  • smaller
  • heavily vascularized

Question 5

The umbilical cord consists of what 3 vessels?

Answer 5

2 arteries

1 vein (larger- oxygen/nutrient rich blood from mom)

Question 6

Identify the classifications of each category of twins shown in the provided image,

Answer 6

• dichorionic diamnionic
• dichorionic diamnionic (fused)
• monochorionic diamnionic
• monochorionic monoamnionic