Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Reproductive System > Placenta > Flashcards

Placenta Flashcards

1
Q

When does the placenta start developing?

A

2nd week of development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is week 2 of development also known as?

A

‘Week of 2s’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens in week 2?

A

Two distinct cellular layers emerge

Outer cell mass

  • syncytiotrophoblast
  • cytotrophoblast

Inner cell mass - becomes bilaminar disk

  • ephiblast
  • hypoblast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When does implantation begin?

A

Day 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens by the end of the 2nd week?

A

Conceptus has mechanically implanted

Embryo and its cavities are suspended by the connecting stalk to the chorionic cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 2 cavities?

A

Amniotic cavity

Yolk sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens to the yolk sac?

A

Disappears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens to the amniotic sac?

A

Enlarges to surround foetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to the chorionic sac?

A

Occupied by expanding amniotic sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does implantation achieve?

A

Establishes basic unit of exchange

  • primary villi
  • secondary villi
  • tertiary villi

Anchors placenta

Establish maternal blood floe within the placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are primary villi?

A

Early finger-like projections of trophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are secondary villi?

A

Invasion of mesenchyme into core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are tertiary villi?

A

Invasion of mesenchyme core by foetal vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What separates maternal blood from the foetal capillary wall?

A

One layer of trophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a chorionic villus?

A

Finger like projections of trophoblast that are in the inner connective tissue core of the placenta and

Maximise surface area for foetal blood flow - contain small blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What implantation defects may occur?

A 
Ectopic pregnancy 
Placenta praevia
Placenta accreta
Placental insufficiency
Pre-eclampsia
17
Q

What is an ectopic pregnancy?

A

Implantation of embryo at site other than the uterus

18
Q

What is placenta praevia?

A

Implantation in the lower uterine segment

  • can block cervix
  • can require a c section
19
Q

What controls the level of invasion in implantation?

A

In the presence of a conceptus - endometrium transforms into the decidua

The decidual reaction provides the balancing force for the invasive force of the trophoblast

20
Q

What is placenta accreta?

A

Placenta invades too deep

Insufficient decidual reaction

21
Q

What is placental insufficiency?

A

Inadequate blood flow to the placenta

22
Q

What is pre-eclampsia?

A

Maternal high blood pressure caused by insufficient invasion by the placenta

23
Q

How does the structure of the chorionic villus structure change during the pregnancy?

A

In first trimester - the villus has a thicker barrier

Third trimester - barrier is thinner as cytotrophoblast disappears

24
Q

What are the vessels in the umbilical cord?

A

Two umbilical arteries
- deoxygenated blood from foetus to placenta

One umbilical vein
- oxygenation blood from placenta to foetus

25
Q

What hormones are produced by the placenta?

A

Protein hormones

  • human chorionic gonadotrophin
  • human chorionic somatomammotrophin
  • human chorionic thyrotrophin
  • human chorionic corticotrophin

Steroid hormones

  • progesterone
  • oestrogen
26
Q

Why does the placenta produce steroid hormones?

A

Takes over from the corpus luteum in the 11th week

27
Q

Where is human chorionic gonadotrophin produced?

A

Syncytiotrophoblast

28
Q

What is the role of human chorionic gonadotrophin?

A

Supports secretory function of corpus luteum

29
Q

When is human chorionic gonadotrophin produced?

A

First 2 months of pregnancy

30
Q

What is the role of human chorionic somatomammotrophin?

A

Regulating metabolism in pregnant women - increases glucose availability to foetus

31
Q

What is the role of human chorionic thyrotrophin?

A

Acts similar to TSH

32
Q

What is the role of human chorionic corticotrophin?

A

Acts similar to ACTH

33
Q

What are the roles of the placental steroid hormones?

A

Maintaining pregnant state

Progesterone - increases maternal appetite

34
Q

What are the transport functions of the placenta?

A

Simple diffusion

  • water
  • electrolytes
  • urea
  • gases

Facilitated diffusion
- glucose

Active transport - transporters in syncytiotrophoblast

  • amino acids
  • iron
  • vitamins
35
Q

How is passive immunity transferred?

A

IgG transferred across placenta via a receptor mediated process

36
Q

What harmful substances can cross the placenta?

A

Thalidomide
Alcohol
Illegal drugs
Smoking contents

Drugs

  • anti-epiletpics
  • warfarin
  • ACEi
37
Q

WHat are the effects of alcohol crossing the placenta?

A

FAS - foetal alcohol syndrome

ARND - alcohol related neurodevelopmental disorder

Reproductive System (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions