2. Implantation, placenta, placental circulation, fetal membranes

Question 1

What is implantation?

Answer 1

the stage in embryonic development in which the blastocyst hatches as the embryo, and adheres to the wall of the uterus.

Question 2

What is implantation?

Answer 2

the stage in embryonic development in which the blastocyst hatches as the embryo, and adheres to the wall of the uterus.

Question 3

At the time of implantation, the mucosa of the uterus is in the (1)____ phase (Fig. 3.13), during which time (2)____ become coiled and the tissue becomes succulent.

Answer 3

1. secretory
2. uterine glands and arteries

Question 4

At the time of implantation, the mucosa of the uterus is in the secretory phase (Fig. 3.13), during which time uterine glands and arteries become coiled and the tissue becomes succulent.

• > As a result, three distinct layers can be recognized in the endometrium.
• > What are they?

Answer 4

a superficial compact layer, an intermediate spongy layer, and a thin basal layer (Fig. 3.13).

Question 5

IMPLANTATION

Normally, (1)___ implants in the endometrium along the anterior or posterior wall of the body of the uterus, where it becomes embedded between (2)____

Answer 5

1. the human blastocyst
2. the openings of the glands

Question 6

What is The decidua?

Answer 6

The functional layer of the pregnant endometrium

Question 7

Decidual reaction (decidualization)

starts at the site of (1)___ and spreads over, except at the (2)___

• (3)___ transform into large, poligonal, epitheloid cells (decidual cells)
• (4)___ accumulate in the cells
• (5)___ is increased

Answer 7

1. implantation
2. cervix
3. connective tissue cells
4. glycogen and lipids
5. angiogenesis

Question 8

4 Functions of The decidua?

Answer 8

1. Forms the maternal placenta (basal plate)
2. Protects and nourishes the conceptus before the utero-placental circulation begins
3. Prevents attachment of the placenta to deeper layers (myometrium) of the uterus (placenta accreta)
4. Sheds off during birth (decidua means falling away)

Question 9

4 Functions of The decidua

1. Forms the ____
2. Protects and nourishes the conceptus before ____ begins
3. Prevents attachment of the placenta to ___
4. Sheds off during ___

Answer 9

1. maternal placenta (basal plate)
2. the utero-placental circulation
3. deeper layers (myometrium) of the uterus (placenta accreta)
4. birth (decidua means falling away)

Question 10

Describe Decidual reaction (decidualization):

Answer 10

starts at the site of implantation and spreads over, except at the cervix

• connective tissue cells transform into large, poligonal, epitheloid cells (decidual cells)
• glycogen and lipids accumulate in the cells
• angiogenesis is increased

Question 11

Identify

Answer 11

Question 12

The pellucide zone free blastocyst is a prerequisite to implantation

→ What are the 3 advantages of hatching?

Answer 12

1. further growing is allowed
2. more efficient absorbtion of nutritients
3. it is necessary to implantation

Question 13

Implantation to the ___ part of the uterus wall

Answer 13

anterior, posterior or upper part of

Question 14

What happen during Implantation of the blastocyst?

Answer 14

• The syncytiotrophoblast (ST) invades the maternal tissue (primitive villi)
• The ST pulls the conceptus into the endometrium
• Lacunae appear filled with liquid in the ST
• The ST erodes the maternal sinusoid vessles
• The lacunae fuse with the maternal sinusoids
• Primitive – uteroplacental circulation begins
• Completed by the end of the 2nd week

Question 15

Implantation of the blastocyst

1. The syncytiotrophoblast (ST) invades the __
2. The ST pulls the___ into the endometrium
3. ____ appear filled with liquid in the ST
4. The ST erodes ___
5. The lacunae fuse with the ___
6. Primitive – ___ begins
7. Completed by the end of the __ week

Answer 15

1. maternal tissue (primitive villi)
2. conceptus
3. Lacunae
4. the maternal sinusoid vessels
5. maternal sinusoids
6. uteroplacental circulation
7. second

Question 16

Implantation of the blastocyst

Secretional activity of The syncytiotrophoblast (ST)

→ The role of hormones?

Answer 16

• block the maternal immune system
• Prevent menstruation: human chorionic gonadotropin hormone (hCG)

Question 17

What are the 2 requirements for implantation?

Answer 17

1. Zona –free blastocyst (hatching)

2. Adplantation

Question 18

Implantation occurs when __

Answer 18

days 6-14.

Question 19

3 main events happening during implantation

Answer 19

• Adplantation (days 6-7)
• Implantation
• Coagulation plug

Question 20

3 main events happening during implantation

Answer 20

• Adplantation (days 6-7)
• Implantation
• Coagulation plug

Question 21

What happens during implantation?

Answer 21

• Blastocyst - endometrium interaction of adhesion molecules
• “receptive window” (about days 20 -24 of the cycle)
  
  • Loose then firm adherence
  • The trophoblast connects to the epithelium of the endometrium,
  • alignment : the inner cell mass is toward the endometrium

Question 22

What happen during Coagulation plug?

Answer 22

left where the blastocyst has entered the uterine wall (days 12-14).

Question 23

Identify

Answer 23

Question 24

Location of the amniotic sac?

Answer 24

It is inner fetal membrane