FETAL CIRCULATION

Summary

This educational video script delves into fetal circulation, highlighting its distinct structures and processes compared to postnatal circulation. It emphasizes the role of the placenta and umbilical cord in oxygen and nutrient delivery, bypassing the lungs which are inactive in this stage. Key fetal circulation features include the foramen ovale, ductus arteriosus, and ductus venosus, facilitating blood flow. The script guides viewers through a flowchart for clearer understanding and concludes with postnatal changes where these fetal structures close, adjusting circulation for lung involvement in oxygenation.

Takeaways

• 🌟 Fetal circulation is also known as prenatal circulation and is distinct from postnatal circulation due to structural differences.
• 🩸 The placenta and umbilical cord are central to fetal circulation, carrying oxygenated blood from the mother to the fetus.
• 💙 The umbilical vein carries oxygenated blood, while the two umbilical arteries carry deoxygenated blood, which is contrary to the adult circulation.
• 🫀 The foramen ovale is an opening between the right and left atria in the fetal heart, allowing blood to bypass the lungs and enter the systemic circulation.
• 🔄 The ductus arteriosus is a shunt between the pulmonary artery and the aorta, directing blood away from the non-functioning lungs and into the systemic circulation.
• 🔄 The ductus venosus is a connection between the umbilical vein and the inferior vena cava, allowing oxygenated blood to bypass the liver.
• 🌀 Blood from the umbilical vein supplies the liver and the rest goes to the inferior vena cava, where it mixes with deoxygenated blood from the superior vena cava.
• 🚫 The lungs are not involved in fetal circulation as the fetus obtains oxygen and nutrients directly from the mother through the placenta.
• 🛑 Postnatal changes include the closure of the foramen ovale, which becomes the fossa ovalis, and the closure of the ductus arteriosus.
• 📚 Understanding the fetal circulation can be aided by creating a flowchart, which helps to visualize and remember the complex pathways of blood flow.

Q & A

What is fetal circulation?

Fetal circulation, also known as fetal placental circulation or prenatal circulation, refers to the blood circulation that occurs during the prenatal period in a fetus. It is distinct from postnatal circulation due to several structural differences.

How does fetal circulation differ from postnatal circulation?

In fetal circulation, the lungs are not involved as the fetus obtains oxygen and nutrients from the mother through the placenta. In postnatal circulation, the lungs play a crucial role in oxygenating the blood.

What are the key structures involved in fetal circulation?

The key structures involved in fetal circulation include the placenta, umbilical cord, foramen ovale, ductus arteriosus, and ductus venosus.

What is the role of the placenta in fetal circulation?

The placenta performs respiratory, nutritive, and supportive functions for the fetus, facilitating the exchange of oxygen, nutrients, and waste products between the fetus and the mother.

How does the umbilical cord contribute to fetal circulation?

The umbilical cord contains one umbilical vein carrying oxygenated blood from the placenta to the fetus and two umbilical arteries carrying deoxygenated blood back to the placenta.

What is the foramen ovale and its function in fetal circulation?

The foramen ovale is an opening between the right atrium and left atrium of the fetal heart, allowing blood to bypass the pulmonary circulation and directly enter the systemic circulation.

Describe the ductus arteriosus and its significance in fetal circulation.

The ductus arteriosus is a connection between the pulmonary artery and the aorta, allowing blood to bypass the lungs and be circulated systemically. It is essential for fetal circulation as the lungs are not used for respiration.

What is the ductus venosus and its role in fetal circulation?

The ductus venosus is a connection between the umbilical vein and the inferior vena cava, allowing a portion of the oxygenated blood from the placenta to bypass the liver and directly enter the heart.

How does blood flow through the fetal heart?

In fetal circulation, blood from the umbilical vein flows into the liver and then divides, with some going to the inferior vena cava and some bypassing the lungs through the foramen ovale. Blood from the superior and inferior vena cava enters the right atrium, and most of it moves to the left atrium, while some goes to the right ventricle and then to the pulmonary artery, which is connected to the aorta via the ductus arteriosus.

What are the postnatal changes that occur in the fetal circulation structures?

After birth, the foramen ovale closes and becomes the fossa ovalis, and the ductus arteriosus constricts and closes, eventually becoming a fibrous cord known as the ligamentum arteriosum. These changes are necessary for the transition to postnatal circulation.

Why is it important to understand fetal circulation for medical professionals?

Understanding fetal circulation is crucial for medical professionals to diagnose and manage conditions related to fetal development, such as issues with the placenta or umbilical cord, and to understand the transition to postnatal circulation.

Outlines

00:00

🌀 Introduction to Fetal Circulation

The paragraph introduces the concept of fetal circulation, also known as prenatal circulation, which is distinct from postnatal circulation due to structural differences. It emphasizes that during prenatal circulation, the lungs are not involved, and the fetus obtains oxygen and nutrients from the mother via the placenta. The paragraph sets the stage for a detailed discussion of the structures involved in fetal circulation, such as the placenta, umbilical cord, and specific blood vessels. It also mentions the use of a flowchart to aid in understanding the complex circulation process.

05:01

🔍 Structures Involved in Fetal Circulation

This section delves into the structures that are unique to fetal circulation: the placenta, umbilical cord with its two arteries and one vein, foramen ovale, ductus arteriosus, and ductus venosus. It explains the roles of these structures, highlighting that the umbilical vein carries oxygenated blood, unlike typical veins, and the umbilical arteries carry deoxygenated blood, mirroring the pulmonary arteries in postnatal circulation. The foramen ovale is described as an opening between the atria of the heart that allows blood to bypass the lungs, a critical adaptation for fetal life.

10:04

🚀 Detailed Flow of Fetal Circulation

The paragraph provides a detailed explanation of the flow of blood in fetal circulation. It describes how blood from the placenta travels through the umbilical vein, partially to the liver and then through the ductus venosus to the inferior vena cava, and how most of it bypasses the pulmonary circulation through the foramen ovale. It also explains how blood from the right ventricle enters the pulmonary artery and, through the ductus arteriosus, is shunted into the aorta, avoiding the lungs. The paragraph concludes with a visual reference to a diagram that illustrates these pathways.

15:04

🔄 Continuation of Fetal Circulation Pathways

This paragraph continues the description of fetal circulation, focusing on the return path of blood to the placenta. It explains that blood from the aorta goes down the descending aorta, into the internal iliac arteries, and then forms the umbilical arteries that enter the umbilical cord, completing the circuit by delivering deoxygenated blood back to the placenta for reoxygenation. The paragraph reinforces the understanding of fetal circulation with a visual aid, making the complex process more accessible.

20:04

🛑 Postnatal Changes in Circulation

The final paragraph discusses the critical changes that occur after birth to transition from fetal to neonatal circulation. It explains that the foramen ovale, which allowed blood to bypass the lungs in fetal circulation, closes after birth, becoming the fossa ovalis. Similarly, the ductus arteriosus, which connected the pulmonary artery to the aorta, closes postnatally. These closures are essential for the newborn to establish normal pulmonary circulation as the lungs begin to function in gas exchange.

Keywords

💡Fetal Circulation

Fetal circulation refers to the blood flow within a fetus during the prenatal period. It is distinct from postnatal circulation due to structural differences that facilitate the fetus obtaining oxygen and nutrients from the mother through the placenta. In the video, fetal circulation is the central theme, with a detailed explanation of how it differs from adult circulation, highlighting the absence of lung involvement and the role of the placenta.

💡Placental Circulation

Placental circulation is the process by which the fetus exchanges gases, nutrients, and waste with the mother through the placenta. This term is used in the video to describe the unique circulatory system in place before birth, emphasizing the role of the placenta as a critical organ for fetal survival and development.

💡Umbilical Cord

The umbilical cord is a cord that connects the fetus to the placenta, containing blood vessels that transport oxygenated and deoxygenated blood. In the video, the umbilical cord is highlighted as a vital structure in fetal circulation, with two arteries carrying deoxygenated blood to the placenta and one vein carrying oxygenated blood to the fetus.

💡Foramen Ovale

The foramen ovale is an opening in the fetal heart that allows blood to bypass the lungs by channeling it from the right atrium to the left atrium. The video explains its significance in fetal circulation, noting that after birth, the foramen ovale closes, becoming the fossa ovalis, which is a critical change in postnatal circulation.

💡Ductus Arteriosus

The ductus arteriosus is a blood vessel that connects the pulmonary artery to the aorta in the fetal circulation, allowing blood to bypass the lungs. The video describes how this structure is essential for directing blood flow away from the non-functional lungs during fetal life and closes after birth, which is a critical postnatal change.

💡Ductus Venosus

The ductus venosus is a shunt that connects the umbilical vein to the inferior vena cava, allowing oxygenated blood to bypass the liver and enter the heart directly. In the video, it is explained as a part of the fetal circulatory system that is not present in adults, playing a crucial role in ensuring efficient oxygenation of the blood.

💡Postnatal Circulation

Postnatal circulation refers to the blood circulation in a newborn after birth, where the lungs become involved in oxygenation, and the fetal circulatory pathways close. The video contrasts postnatal circulation with fetal circulation, emphasizing the structural changes that occur to adapt to breathing and the absence of the placenta.

💡Oxygenation

Oxygenation is the process of supplying oxygen to the blood. In the context of the video, oxygenation is discussed in relation to how the fetus obtains oxygen from the mother through the placenta, as opposed to postnatal circulation where the lungs are responsible for oxygenation.

💡Structural Differences

Structural differences refer to the distinct anatomical features of fetal circulation compared to postnatal circulation. The video highlights several structures unique to the fetus, such as the foramen ovale, ductus arteriosus, and ductus venosus, which are essential for fetal life but close or become non-functional after birth.

💡Circulatory System

The circulatory system is the body's network of blood vessels and the heart, responsible for transporting blood throughout the body. The video provides an in-depth look at the fetal circulatory system, explaining how it differs from the adult circulatory system and the changes that occur at birth.

💡Blood Vessels

Blood vessels are the tubes that transport blood throughout the body. In the video, specific blood vessels such as the umbilical arteries and vein are discussed in the context of fetal circulation, explaining their roles in carrying oxygenated and deoxygenated blood between the fetus and the placenta.

Highlights

Fetal circulation is also known as prenatal circulation, occurring during the prenatal period.

Structural differences exist between prenatal and postnatal circulation.

Lungs are not involved in fetal circulation; fetus obtains oxygen and nutrients from the mother through the placenta.

Fetal circulation includes blood vessels within the placenta called umbilical arteries and vein.

Umbilical arteries carry deoxygenated blood, while the umbilical vein carries oxygenated blood.

Foramen ovale is an opening between the right and left atria in the fetal heart.

Ductus arteriosus is a connection between the pulmonary artery and the aorta in fetal circulation.

Ductus venosus is a connection between the umbilical vein and the inferior vena cava.

The placenta performs respiratory, nutritive, and supportive functions for the fetus.

The fetal heart's right side contains deoxygenated blood, while the left side contains oxygenated blood.

Blood from the umbilical vein bypasses the lungs and enters the systemic circulation through the foramen ovale.

Ductus arteriosus allows blood to be shunted away from the lungs and into the aorta.

Ductus venosus helps direct oxygenated blood from the umbilical vein to the inferior vena cava.

After birth, the foramen ovale closes and becomes the fossa ovalis.

The ductus arteriosus closes after birth, and failure to close results in patent ductus arteriosus.

Understanding the fetal circulation involves learning about the placenta, umbilical cord, foramen ovale, ductus arteriosus, and ductus venosus.

A flowchart is a helpful tool for remembering the steps of fetal circulation.

The video suggests creating a flowchart to better understand and remember fetal circulation.

Transcripts

today we are going to discuss about the

fetal circulation fetal circulation or

fetal placental circulation fetal

circulation is also referred to as

prenatal circulation because this is the

circulation that is happening during the

prenatal period and is the circulation

same as that in the postnatal period no

there are many structural differences

during the prenatal circulation and the

postnatal circulation so in this topic

in this video we are going to mainly

discuss about the circulation during the

prenatal period or in the fetus and what

are the structures that are involved in

the circulation during the fetal life so

the fetal circulation or the feed of

placental circulation it includes the

efforts of um glycol called the blood

vessels within the placenta that carry

the fetal blood so here we can find the

involvement of unlike al called

blood vessels and the placenta that

carries the fetal blood and the lungs

are not involved in this type of

circulation this is the main difference

that we see in the prenatal circulation

and the postnatal circulation in the

postnatal circulation or in adult human

body or even after even after just the

birth of the baby when the normal the

normal circulation starts the lungs are

actively involved in the process of

circulation they have a very important

responsibility of carrying out the

oxygenation of the blood but here the

lungs are not involved the fetus obtains

its oxygen and nutrients from the mother

through the placenta and Liam like--all

called so this was just an introduction

about the feat of placental circulation

now we are going to understand about

this feat of placental circulation and

here we are going to take the help of a

flow chart because when we will be

understanding that flow chart it will be

easy to remember all these all these

steps of the circulation so this is the

fetal circulation this picture

many times we all see whenever we study

about the fetal circulation in any book

or from any source this is a very

commonly seen picture but but this is

very difficult to understand that what

kind of circulation is taking place

among these chambers these points we are

going to discuss here in a very simple

way so right now I am NOT explaining the

picture but first of all for

understanding the fetal circulation what

we need to understand is the structures

involved in the fetal circulation so the

first structure that is involved is

placenta and the unlike al called

then second is the blood vessels in the

M like--all cord

third is foramen ovale fourth ductus

arteriosus fifth ductus venosus these

are the these are the structures that

are different from the postnatal

circulation all these structures you

will never find in a postnatal or adult

human body circulation but these are

found in the fetal circulation so before

going to the fetal circulation first of

all we need to understand about these

structures so we will be dealing with

them one by one this is this is the

picture of the placenta and the

umbilical cord here you can see this is

the placenta placenta is is performing

many functions the respiratory function

the nutritive functions the support for

the fetus all these functions are

performed by the placenta then it is

covered by two layers amnion and chorion

and from the placenta comes out your

unlike al cord this is the unlike al

cord which is covered by the Wharton's

jelly and this is the whole structure of

the placenta and the unlike al cord then

when we take a cross section of the am

like alcott we can easily find the blood

vessels in the M like al ghad' see here

this this is the cross section of um

glycol code here that

two vessels are the imply chol arteries

and this one the red and color is the

unlike L win normally what we see is the

arteries carry oxygenated blood and the

veins carry deoxygenated blood but there

are two exceptions in the body one is

the unlike a lottery which carry the

deoxygenated blood and the other one is

the pulmonary artery which also carries

deoxygenated blood the pulmonary

arteries are seen in the postnatal

circulation and this unlikely arteries

play their role in the prenatal

circulation then similarly the vein

which usually carry deoxygenated blood

but here in the fetal circulation the

unlike L vein is the vein or the blood

vessel that carries the oxygenated blood

so this is the main thing that you need

to always keep in mind while studying

about the fetal circulation that there

is only one unlike L vein in the M

like--all called that carries oxygenated

blood and there are two unlike a

lotteries in the umbilical cord which

carry the deoxygenated blood

now the third structure that we are

going to look upon as the foramen ovale

foramen means an opening so this foramen

ovale is a opening between the right

atrium and the left atrium this is the

structure of the heart this the here you

can see the four chambers of the heart

this one is the right atrium this is the

right ventricle this is the left atrium

and this one is the left ventricle the

right side of the heart mainly contains

the deoxygenated blood whereas the left

side of the heart contains the

oxygenated blood during the fetal life

during the prenatal period there is a

opening between the right atrium and the

left atrium which allows the blood

coming through the inferior vena cava

and the superior vena cava to bypass the

pulmonary circulation and directly enter

into the systemic circulation through

the left atrium so the

opening that you are seeing here is

known as foramen ovale and this is

playing a very important role in the

fetal circulation you can see the arrows

pointing both face it means that the

blood can either shift from the right

atrium to the left atrium or can also

come from the left atrium to the right

atrium but the main thing to remember is

the pressure in the right side of the

heart is more than the left side of the

heart therefore the movement of the

blood is always is mainly in from the

right atrium to the left atrium so this

opening is known as foramen ovale this

was the third structure that was to be

discovered and that was to be discussed

for understanding the fetal circulation

now we are coming on to the fourth

structure that is ductus arteriosus the

meaning of ductus arteriosus is a

connection between the two arteries

arteriosus means arteries and ductus

arteriosus represents a connection or a

shunt between the two arteries so if you

see here this one is the pulmonary

artery this is coming out from the right

ventricle and this is the pulmonary

artery whereas this is the IATA

this is coming out from the left

ventricle and this is Iota and you can

see here the arrow pointing in this area

this area represents the ductus

arteriosus this is the area where both

the arteries the IATA and the pulmonary

artery are forming a connection and this

connection is known as ductus arteriosus

here patent ductus is written this is

written paetynn means open if this is

the heart of a adult human being then

this ductus arteriosus must be closed

normally the ductus arteriosus closes

after the birth but when this remains

open this condition is known as patent

ductus arteriosus by

when we have to study about the fetal

circulation then this condition will be

considered as normal so this is the

ductus arteriosus that is our opening

between two arteries the pulmonary

arteries and the IATA then the next

structure defect structure which we need

to discuss is the ductus venosus as the

ductus arteriosus meant the connection

between two arteries here the ductus

venosus means the connection between two

veins now we have to see that what which

are those two veins which are connected

so if you see here this light blue color

vein is the unlike Alvin the unlike

Alvin is coming this is the liver and

one part of the umbilical vein is

supplying the blood to the left portal

vein to the left portal vein whereas the

other part is forming a connection with

the inferior vena cava this one is the

inferior vena cava this is your arm like

a vein and here this is the connection

between the two veins unlike al vein and

the inferior vena cava and this

connection is known as ductus venosus

this is also a common or normal finding

in the fetal circulation but if found in

the in the adult circulation or after

birth then this is considered to be an

abnormality

so this opening sorry this connection is

the ductus venosus so till now we have

discussed the five main structures first

was placenta in the umbilical cord then

we saw the blood vessels there are two

unlike al arteries and one am like

alveen then we studied about the foramen

ovale then ductus arteriosus and at last

ductus venosus so again this is the

fetal circulation and to understand

about the fetal circulation you need to

understand those five terms because now

I'll be discussing this diagram this is

the placenta and the unlike al cord the

red color which you see here is the am

like a vein and the blue colored vessels

are the imply Col

arteries

since the umbilical vein is carrying the

oxygenated blood so it will be entering

the fetus and now come to this diagram

see the first point the blood arrives

via the amp like Alwyn

then this arrives into the liver and

gives a branch to the portal vein and

only about 1/3 of the blood reaches the

inferior vena cava rest 2/3 of the blood

goes to the liver so level is the is the

main organ or the first organ that that

gets and an extensive supply of

oxygenated blood so here this connection

is ductus venosus the connection between

the unlike al vein and the inferior vena

cava

now this inferior vena cava has reached

into the right atrium and from here the

superior vena cava is also bringing the

deoxygenated blood then you can see this

arrow this is pointing towards the

foramen of avail it means that most of

the blood is going directly into the

left atrium and only some amount of

blood is coming down into the right

ventricle then from this right ventricle

the blood the blood is going into the

pulmonary artery and from the right

atrium the blood is going down into the

left which ventricle and then to the

Iota and here between the IATA and the

pulmonary artery there is again a

connection and this connection is your

ductus arteriosus this connects the IATA

with the pulmonary artery further

shunting the blood away from the lungs

and into the iota since here the

involvement of lung is not there that is

why the blood cannot go to the lungs so

this is the connection that is there so

that if any blood is present inside the

pulmonary artery that directly goes into

the aorta and can carry out the systemic

circulation so this is your fetal

circulation now we are going to discuss

it in two parts we are going to make the

flowchart on the earth by dividing it in

two parts so this one is the first part

that we

be discussing then this box will be the

second part and this box will be the

third part now we are starting with the

first part the first part was our

placenta and DM like Alwyn so what will

happen here first of all the placenta

from the placenta arises the unlike a

cord from the umbilical cord one unlike

Alvin is there and to UM like--all

arteries are present so in the umbilical

cord one unlike Alvin is there and ii am

like--all arteries are present my Calvin

carries the oxygenated blood

whereas the unlike all arteries carry

the deoxygenated blood so this is about

the first part of our fetal circulation

that from the placenta the umbilical

cord arises and the unlike Olcott

contains two things one am like a vein

and to him like a arteries then we are

coming on to the next part the next box

then from the umbilical vein this unlike

Alwyn will get will give the supply to

the two parts here you can see the imply

Calvin is giving the supply of the blood

to the two parts one is the portal vein

that is present in the liver and the

next is inferior vena cava and this

connection between the imply Cal vein

and the inferior vena cava is the ductus

venosus you can see in this diagram

which we discussed earlier also this is

the umbilical vein and this is the

inferior vena cava and here the

connection that is present is the ductus

venosus so this is how the ductus

venosus will be formed and the blood

will move on further to the inferior

vena cava then from the inferior vena

cava the blood will go into the right

atrium you can see here in this diagram

from the inferior and the superior vena

cava the blood is coming into the right

atrium

then from the right atrium it has two

paths either to go into the right

ventricle or to go in the left atrium

and this will be because of the presence

of foramen ovale since the foramen ovale

is present here that is why the blood

from the right atrium will go into the

left atrium this was the structure that

I had already shown you this is the

presence of the foramen ovale which

allows the passage of blood from the

right atrium into the left atrium so

these are the two pathways which the

blood from the right atrium can follow

then the third structure here the right

atrium and the right sorry the right

ventricle and the right atrium we are

taking into consideration from the right

ventricle the blood can go into the

pulmonary artery and from the left

atrium the blood can go into the left

ventricle you can see here from this

right atrium the blood can come into the

right ventricle and then from right

ventricle it will go to the pulmonary

artery and from the left atrium it can

come into the left ventricle then from

the pulmonary artery and from the left

ventricle both of these will join into

the aorta here you can see this is the

pulmonary artery it also joins with the

IATA and this is the left ventricle from

here the elta originates so the

connection between the pulmonary artery

and the IATA is known as ductus

arteriosus so this is the connection

this is the connection between the

pulmonary artery and the IATA that is

known as ductus arteriosus so here we

have come across all the three terms

foramen ovale ductus arteriosus and

ductus venosus this was the structure of

the ductus arteriosus a connection

between the pulmonary artery and the

IATA now after the iota where will this

blood go and how will it come back

into the circulation in the placenta so

you can see here this is the whole fetal

circulation in another kind of picture

this is the iota then one branch of iota

that is the descending iota is coming

down now we will see how this blood will

come back into the placenta from the

iota the blood will come into the

descending iota

then from the descending iota it will

enter into the internal iliac artery

from the internal iliac artery it will

join it will form two arteries right

internal iliac artery and the left

internal iliac artery you can see here

this yellow portion this is the

descending aorta which is which is

bifurcating to form the internal iliac

arteries this one is the right internal

iliac artery and this is the left

internal iliac artery then the right

internal iliac artery and the left hand

internal iliac artery will form the

unlike L arteries you can see in this

diagram at the bottom the internal iliac

arteries are forming the unlike all

arteries so both the internal iliac

arteries right and left will form the

glycol artery and these two unlike L

arteries will enter into the umbilical

cord which we saw in the first in the

second picture that was the blood

vessels in the umbilical cord I told you

that there are two I'm like allot reefs

so where are these two umbilical

arteries coming from these two are

Michael arteries are coming from the

right internal iliac artery and the one

from the left internal iliac artery then

they will enter into the unlike al cord

and this son glycol cord will further

meet up with the placenta to give away

the day of deoxygenated blood for the

process of oxygenation and whereas this

oxygen received to the placenta from the

maternal circulation or from the mother

so so now when you are looking at this

picture

now after

understanding about the fetal

circulation now this picture will be

very easy to understand that how the

fetal blood circulation is occurring

from the placenta to the liver then to

the heart then again coming back to form

the umbilical arteries and ending up at

meeting with the placenta so this is

about the fetal circulation now one last

thing that we all must know that what

are the afterbirth changes after birth

changes are the postnatal changes in the

fetal circulation this is the fetal

heart this is the fetal heart and this

is the newborn heart I told you that all

these openings which are present there

are normal for the fetal heart but not

for the newborn heart they need to be

closed for the proper functioning during

the postnatal period

so this foramen ovale which was open

during the fetal heart circulation now

after the birth or in the newborn heart

this foramen ovale gets closed and this

is known as fossa ovalis this structure

turns out to be known as fossa ovalis

and this is the ductus arteriosus that

was opened during the fetal circulation

now this structure will be known as

ductus arteriosus and now this is closed

so this is about the afterbirth changes

or the postnatal changes in the fetal

heart circulation and in the newborn

heart circulation I hope that's that

this topic is clear to you and and one

suggestion I would like to give you that

the flowchart which I have discussed it

would be very nice if you try to make it

on your own study from this video and if

you want then copy the flowchart and

then try to understand the flowchart on

your own then this fetal circulation you

will be never never able to forget so

this was all about the fetal blood

circulation hope you liked the video and

do subscribe and like for the D coming

up videos thank you