IB Biology Topic D3.1.18 Role of the Placenta in Foetal Development Inside the Uterus Revision Notes (HL)

IB Biology Topic D3.1.18 Role of the Placenta in Foetal Development Inside the Uterus Revision Notes (HL) | RevisionDojo

Written by official IB examiners

The Placenta Exchanges Materials Between Mother and Foetus Without Mixing Their Blood

The placenta is the lifeline between a mother and her developing foetus.
It supports the foetus through nutrient and gas exchange, hormone production, and immune protection.

Definition

Placenta

The placenta is a temporary organ that forms during pregnancy. It connects the foetus to the uterine wall via the umbilical cord, acting as a bridge for the exchange of substances between mother and baby.

Note

The placenta is unusual because it is made of foetal tissue but works inside the maternal body.

Nutrient and Gas Exchange Happens Across Placental Villi

The placenta supplies the foetus with nutrients and oxygen, and removes waste such as carbon dioxide.
Maternal blood flows into spaces called intervillous spaces.
Foetal blood flows in capillaries inside the chorionic villi, finger-like projections that give a large surface area for exchange.
The two blood supplies come very close but never mix, which keeps the barrier thin for fast exchange.

Tip

The large surface area of the chorionic villi speeds up exchange, much like the alveoli in the lungs.

Four Transport Mechanisms Move Substances Across the Barrier

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Note

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Excepteur sint occaecat cupidatat non proident

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Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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The Placenta Exchanges Materials Between Mother and Foetus Without Mixing Their Blood

The placenta is the lifeline between a mother and her developing foetus.
It supports the foetus through nutrient and gas exchange, hormone production, and immune protection.

Definition

Placenta

Note

The placenta is unusual because it is made of foetal tissue but works inside the maternal body.

Nutrient and Gas Exchange Happens Across Placental Villi

The placenta supplies the foetus with nutrients and oxygen, and removes waste such as carbon dioxide.
Maternal blood flows into spaces called intervillous spaces.
Foetal blood flows in capillaries inside the chorionic villi, finger-like projections that give a large surface area for exchange.
The two blood supplies come very close but never mix, which keeps the barrier thin for fast exchange.

Tip

The large surface area of the chorionic villi speeds up exchange, much like the alveoli in the lungs.

Four Transport Mechanisms Move Substances Across the Barrier

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic D3.1.18: Role of the Placenta in Foetal Development Inside the Uterus Notes

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

The Placenta Exchanges Materials Between Mother and Foetus Without Mixing Their Blood

Nutrient and Gas Exchange Happens Across Placental Villi

Four Transport Mechanisms Move Substances Across the Barrier

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

The Placenta Exchanges Materials Between Mother and Foetus Without Mixing Their Blood

Nutrient and Gas Exchange Happens Across Placental Villi

Four Transport Mechanisms Move Substances Across the Barrier

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account