Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Y2 - Repro > Lecture 11 - Placenta > Flashcards

Lecture 11 - Placenta Flashcards

(81 cards)

Start Studying
1
Q

What is the general function of the placenta?

A

To support the developing embryo

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

What are the 2 parts to the placenta?

A

Fetal maternal organ:

Fetal part

Maternal part

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

What is the fetal part of the placenta?

A

Part that develops from the chorionic sac that’s the outermost fetal membrane

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

What is the maternal part of the placenta?

A

Part derived from endometrium (the innermost layer of the uterine wall)

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

Where does fertilisation of the ovum take place?

A

Ampulla

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

What happens after the ovum get fertilised?

A

Mitotic divisions occur
16 cell = morula
Becomes blastocyst
Blastocyst has inner cell mass and outer cell mass

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

Which part of the blastocyst (inner cell mass or outer cell mass) becomes the embryo/ is called the embryoblast?

A

Inner cell mass

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

What are the cells called that make up the outer cell mass before they differentiate?

A

Trophoblasts

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

What needs to happen to the endometrial stromal cells before implantation can occur?

A

Decidualisation

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

What is Decidualisation?

A

The process by which stromal cells differentiate into specialised Decidual cells

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

What are the 2 main functions of decidual cells formed by decidualisation?

A

They control the depth of invasion of the trophoblasts into the endometrium

Protects the conceptus from maternal immune rejection since contains foreign DNA (Fathers)

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

What is considered normal implantation?

A

Location: upper part of uterus (fundus)

Normal invasion: within decidua (stratum functionalis)

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

What cells of the embryo are important in implantation?

A

Trophoblasts of outer cell mass

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

What important structures are important on the endometrium for implantation?

A

Pinopodes
Integrin receptors

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

What forms the loose connection in implantation?

A

Microvili of trophoblasts join to the pinopodes of the endometrium

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

What forms the strong connections in implantation?

A

Integrins on trophoblasts bin to integrin receptors on endometrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 2 connections that form in implantation?

A

Loose connection = microvilli on trophoblasts join to pinopodes

Strong connection = Integrins on trophoblasts join to integrin receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What 2 different types of cells do the trophoblasts differentiate into?

A

Cytotrophoblast
Syncytiotrophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of the syncytiotrophoblasts?

A

Makes HCG to maintain corpus luteum preventing endometrium from shedding

Makes roots invading endometrium in the stroma
Makes enzymes involving invasion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the gaps between the invading syncytiotrophoblasts roots called?

A

Lacunae (fill with blood)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the function of the cytotrophoblasts?

A

They send projections through the syncytiotrophoblasts invading roots forming the Primary Villus with intervillus spaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the extraembryonic mesoderm?

A

The layer between the cytotrophoblasts and the embryoblast/inner cell mass

The cavity the fills with fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the function of the connecting stalk?

A

It becomes the umbilical cord that connects the embryo to placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What forms the secondary villus?

A

The somatic layer of the extra embryonic mesoderm invades into the primary villus forming the 3 layers secondary villus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does the connecting stalk differentiate into?
3 blood vessels 2 umbilical arteries 1 umbilical vein
26
What takes place to format the tertiary villus?
Chorionic vessels grow up into the villus Umbilical vein and artery start to fill intervilous spaces
27
What are the cotyledons? What forms the cotyledons?
They are groups of tertiary villi Formed by decidual cells invaginate into the growing placenta forming septa that separate the cotyledons
28
What happens to the layers of the placenta as it matures?
Layers get thinner especially the Cytotrophoblast layer To allow for material exchange
29
What are the 3 important embryonic sacs?
Yolk sac Amniotic sac Chorionic sac
30
What happens to the yolk sac during development?
Disappears
31
What happens to the amniotic sac during development?
It enlarges
32
What happens to the chorionic sac during development?
Lies outside the placenta and contains the expanding amniotic sac
33
What occurs when a woman’s water breaks?
Hole formed in the amniotic sac allowing the amniotic fluid out
34
What happens to the thickness of the barriers of the villi as development occurs?
Get thinner until at optimum thickness
35
What type of blood do the two umbilical arteries carry?
Deoxygenated blood
36
Where do the 2 umbilical arteries carry deoxygenated blood to and from?
Deoxygenated blood from the fetus to the placenta
37
What type of blood does the umbilical vein transport?
Oxygenated
38
Where does the umbilical vein transport oxygenated blood to and from?
Oxygenated blood from the placenta to the fetus
39
What is the outer transparent layer of the placenta?
Aminon membrane
40
What are the vessels that can be even on the outer layer of the placenta?
Chorionic vessels located under the amnion
41
Look at slide 20 to see what cotyledons look like
42
How can implantation go wrong?
Incorrect site Incorrect depth
43
What is a pregnancy called that occurs outside the uterus?
Ectopic pregnancy
44
Why is an ectopic pregnancy not a viable pregnancy?
There’s no control in the depth of invasion of the conceptus at the site This can lead to very deep invasion leading to haemorrhage
45
What is Placenta Praevia?
When implantation is too low down in the uterus leading to a low lying placenta which can cover the cervical oss
46
Why is placenta praevia a worrying sign?
The placenta is blood rich so if teh baby try’s to push through during child birth it could rupture leading to a massive haemorrhage = antepartum haemorrhage
47
What problems can occur when the implantation is too shallow?
Blood supply to placenta can be compromised -placental insufficiency -pre-eclampsia
48
What are the 3 conditions called when the implantation occurs to deep?
Placenta accrete Placenta increta Placenta percreta
49
What are the 3 conditions called when the implantation occurs to deep?
Placenta accrete Placenta increta Placenta percreta
50
What is placenta accrete?
When the placenta invades beyond the functional layer (decidual) to basal layer
51
What is placenta increta?
When the conceptus invades through the myometrium
52
What is placenta percreta?
When the conceptus invades all the way through the entire uterus
53
How can you remember what depths are invaded too with the 3 to deep invasions?
Most superficial to deep in alphabetical order Placenta acrete Placenta increta Placenta percreta
54
Why is invasion too deep bad?
Can cause significant post partum haemorrhage
55
What is pre eclampsia?
Condition where mother develops high blood pressure during pregnancy or post partum which can lead to proteinuria
56
Why does high blood pressure occur in pre-eclampsia?
Occurs since the conceptus doesn’t invade deep enough it is too shallow This leads to blood vessels that develop being too narrow This can lead to poor blood flow to placenta and therefore causing high blood pressure ini the mother
57
What is the general function of the placenta?
Supports the growing fetus
58
What are the main functions of the placenta?
Transfer: -gas exchange -nutrient exchange -waste removal -transferring IMMUNITY Endocrine: -protein hormones -steroid hormones The hormones maintain pregnancy
59
What are some protein hormones produced by the placenta?
Human chorionic gonadotrophin (HCG) Human placental lactogen (hPL) Placental growth hormone (PGH) Corticotropin-releasing hormone (CRH)
60
What is thee function of HCG?
Maintains the corpus luteum which produces high amounts of progesterone (little oestrogen) maintains pregnancy
61
What are the steroid hormones made by the placenta?
Progesterone Oestrogen
62
What cells produce HCG in the placenta?
Syncytiotrophoblasts So is pregnancy specific
63
What is a disease where HCG is made?
Trophoblast disease called molar pregnancy
64
What is a molar pregnancy?
A non viable pregnancy where there’s the wrong number of chromosomes Must be treated like a miscarriage
65
Why must a molar pregnancy be treated seriously as a miscarriage?
Molar pregnancies can become a malignancy called Choriocarinoma
66
What is the importance of the steroid hormones (progesterone and oestrogen made by the placenta?
Maintains the pregnancy state taking over from the corpus luteum
67
How are substances transported across the placenta?
Simple diffusion Facilated diffusion (glucos) Active transport
68
What cells express the transporters for active transport in the placenta ?
Syncytiotrophoblasts
69
What is actively transported across the placenta?
Amino acids Iron Vitamins
70
Why is good uteroplacental circulation essential for survival of the embryo?
Gas exchange relies on simple diffusion So good blood flow needed to maintain a good concentration gradient
71
Why are women advised to lie on the side when they’re pregnant not on their back?
Baby will compress aorta reducing blood supply to placenta imparting conc grad for gas exchange
72
How is passive immunity granted to the developing embryo in the placenta?
IgG taken up by receptor mediated endocytosis
73
What blood vessels transport wastes like CO2, urea, uric acid and bilirubin from the baby to the placenta?
Umbilical arteries
74
What is a teratogen?
An agent that causes malformation in the embryo
75
What are some harmful substances that can cross the placenta?
Thalidomide Alcohol (fetal alcohol syndrome) Therapeutic drugs (anti epileptic drugs, warfarin, ACE inhibitor) Drug abuse (fetus becomes dependant) Maternal smoking (affects placental growth)
76
What is an example of an anti-epileptic drug?
Sodium valproate
77
What negative affect on development can sodium valproate have?
Neural tube defects
78
What are the 4 stages teratogenesis can occur?
Pre-embryonic (lethal effects) Embryonic (very sensitive) Fetal (quite sensitive) After embryonic period ( risk for structural defects is low) except CNS
79
What are the main serious infections that can cross the placenta in pregnancy?
Toxoplasmosis Other- syphilis, HIV, varicella Rubella Cytomegalovirus Herpes Simplex
80
How can you remember the infections that can cross the placenta in pregancy?
TORCH infections Toxoplasmosis Other - syphilis, HIV, varicella Rubella Cytomegalovirus Herpes simplex
81
Where do you risk picking u ptoxoplasmosis?
Around cats

Y2 - Repro (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions