The Anatomy of a C-Section

Summary

This educational video script delves into the complexities and variations of cesarean sections, a procedure accounting for 20-30% of global births. It explains the anatomical landmarks involved, from the initial skin incision to the deeper layers including the rectus sheath and peritoneum, leading to the uterus. The script also touches on historical perspectives and the emerging science of how C-sections may affect an infant's microbiome, offering viewers a comprehensive look at both the medical and scientific aspects of this common birth procedure.

Takeaways

• 📈 C-sections are increasing worldwide, with an average of 20-30% of all births being performed via this method.
• 🔍 There is no universal procedure for a C-section; the type of procedure depends on various factors such as the doctor and the circumstances.
• 🔑 The location of the incision typically ranges from two to five centimeters above the pubic symphysis and is influenced by the anterior superior iliac spine (ASIS).
• 🔪 The initial cut avoids cutting through muscles to reduce recovery time and complications, focusing on the superficial layers of the abdomen.
• 🤲 Tissue is often torn apart by hand or with blunt instruments to minimize blood vessel damage and ease healing.
• 🛡️ The rectus sheath, a connective tissue layer surrounding the rectus abdominis muscle, is an important landmark during the procedure.
• 🤝 The Linea Alba, a white line down the center of the abdomen where connective tissue layers converge, is targeted for the second cut to avoid muscle tissue.
• 👶 After the peritoneum is cut, the uterus is accessed, and the infant can be delivered along with the placenta and amniotic sac.
• 🧵 The closure of the uterus and the surrounding tissues involves suturing, with techniques varying depending on the procedure.
• 🌐 The impact of C-sections on an infant's microbiome is an emerging area of study, with differences observed compared to vaginal births.
• 📚 Historically, C-sections were only performed to save the baby's life due to high maternal mortality rates, but modern medicine has changed this perspective.

Q & A

Why are cesarean sections becoming more common?

The exact reasons for the increase in cesarean sections are not universally agreed upon. It's not just due to women electing to have them more frequently or emerging conditions necessitating the procedure. The rates vary by country but globally, around 20 to 30 percent of all births are cesarean sections.

What factors determine the type of cesarean section performed?

The type of cesarean section performed depends on various factors including the doctor's preference, whether it's an emergency, the health of the mother and baby, and whether the woman has had multiple cesarean sections in the past.

What is the general area where the incision is made during a cesarean section?

The incision is generally made anywhere from two to five centimeters above the pubic symphysis and a couple of centimeters medial to the anterior superior iliac spine (ASIS), although the exact location can vary depending on the procedure.

Why do surgeons avoid cutting through the abdominal muscles during a cesarean section?

Surgeons avoid cutting through the abdominal muscles to reduce recovery time and minimize the risk of complications. Cutting through muscle can prolong healing and increase the chance of severing blood vessels.

What is the purpose of the rectus sheath in the context of a cesarean section?

The rectus sheath is a connective tissue layer surrounding the rectus abdominis muscle. During a cesarean section, part of the rectus sheath may be cut away to expose the underlying muscle and facilitate the procedure.

What is the significance of the Linea Alba during a cesarean section?

The Linea Alba is a fibrous structure running down the center of the abdomen where the connective tissue layers of the obliques converge. Surgeons aim to make their second cut through the Linea Alba to avoid cutting through muscle tissue.

What is the role of the peritoneum in a cesarean section?

The peritoneum is a thin layer that lines the inside of the abdominal wall and covers the abdominal organs. It must be cut through to access the uterus during a cesarean section.

How is the uterus accessed during a cesarean section?

After cutting through the peritoneum, the uterus is accessed. The incision on the uterus is typically transverse and positioned where the infant's head is located to facilitate birth.

What are some of the differences in the procedure based on whether it's an emergency or planned cesarean section?

The procedure may vary based on whether it's an emergency or planned cesarean section. For instance, an emergency section may prioritize speed to save the life of the mother or baby, whereas a planned section may allow for more precise and less invasive techniques.

What are some of the historical changes in the approach to cesarean sections?

Historically, cesarean sections were only performed to save the baby's life due to the high mortality rate for the mother. Nowadays, they are performed more frequently and safely, with a global average of around 20 to 30 percent of births being cesarean sections.

How might a cesarean section affect an infant's microbiome compared to a vaginal birth?

A cesarean section can result in a different microbiome profile for the infant, which is more similar to the skin on the mother and the operating room environment, rather than the mother's vaginal bacteria as in a vaginal birth. The long-term effects of this difference are still being studied.

Outlines

00:00

🤰 C-Section Overview and Procedure

This paragraph introduces the increasing prevalence of cesarean sections (C-sections) worldwide, which account for 20 to 30 percent of all births. It aims to demystify the procedure by explaining the factors influencing the type of C-section performed, such as whether it's an emergency or planned, and the mother's medical history. The paragraph also outlines the anatomical landmarks considered during a C-section, including the pubic symphysis and anterior superior iliac spine (ASIS), and describes the initial incision made above these areas. It emphasizes that the procedure varies but shares common modern techniques.

05:01

🔪 Anatomy and Steps of a C-Section

This paragraph delves into the detailed anatomy involved in a C-section, starting with the superficial layers of the abdomen, including the epidermis, dermis, hypodermis, and subcutaneous tissue. It explains the rationale behind avoiding cutting through muscles to expedite recovery and reduce complications. The paragraph then describes the deeper connective tissues and muscles encountered, such as the rectus sheath and the rectus abdominis muscle, and the importance of the Linea Alba in making the second cut. It also discusses the peritoneum and the approach to the uterus, including the handling of the greater omentum and small intestines during the procedure. The paragraph concludes with the steps taken to close the uterus, handle the placenta, and suture the various layers of the abdominal wall after the birth.

10:01

👶 Impact of C-Sections on Infant Microbiome

The final paragraph explores the emerging research on the impact of C-sections on an infant's microbiome. It contrasts the process of acquiring beneficial bacteria through the mother's vaginal secretions during vaginal birth with the different microbiome profile observed in infants born via C-section, which resembles the mother's skin and the operating room environment. The paragraph highlights the ongoing investigation into the long-term effects of these differences in microbiome on health and development, reflecting on the significance of this research for future understanding.

Keywords

💡Cesarean Section

A cesarean section, commonly referred to as a C-section, is a surgical procedure used to deliver a baby through an incision made in the mother's abdomen and uterus. It is a significant topic in the video, which discusses the increasing prevalence of C-sections worldwide, accounting for 20 to 30 percent of all births. The script explains that the procedure can be performed for various reasons, not just elective choices or due to emerging conditions.

💡Incisions

Incisions are cuts made into the body during surgery. In the context of a C-section, the script describes the process and the specific areas where incisions are made, such as above the pubic symphysis and the Linea Alba. The type of incision can vary depending on whether it's an emergency or a planned procedure, and the script provides a detailed account of the anatomical landmarks involved in making these incisions.

💡Pubic Symphysis

The pubic symphysis is a cartilaginous joint where the two pubic bones meet at the midline of the pelvis. The video script uses this anatomical landmark as a reference point for where the incision for a C-section is typically made, which is a few centimeters above the pubic symphysis.

💡Anterior Superior Iliac Spine (ASIS)

The anterior superior iliac spine is a bony landmark on the pelvis, which is used as a reference in the script to determine the location for the C-section incision. The incision is made a couple of centimeters medial to the ASIS, highlighting the importance of precise anatomical knowledge in surgical procedures.

💡Integumentary System

The integumentary system is the body's outermost layer, consisting of the skin, hair, nails, and sweat glands. The script explains that during a C-section, the initial incision is made through the superficial layers of the integumentary system, specifically the epidermis, dermis, and hypodermis or subcutaneous tissue, to avoid cutting into the underlying muscles.

💡Rectus Sheath

The rectus sheath is a connective tissue layer that surrounds the rectus abdominis muscle, which is part of the abdominal wall. The script describes how, during a C-section, the surgeon will encounter and may need to cut through the rectus sheath to access the underlying muscles and eventually the peritoneum.

💡Linea Alba

The Linea Alba is a fibrous structure in the center of the abdomen, where the two sides of the rectus sheath come together. In the script, it is mentioned as the area where the surgeon will make a vertical incision through during a C-section, aiming to avoid cutting through muscle tissue.

💡Peritoneum

The peritoneum is the serous membrane that lines the inner wall of the abdomen and covers the abdominal organs. The script explains that after cutting through the Linea Alba, the surgeon will encounter the peritoneum, which is another layer that must be cut through to reach the uterus.

💡Uterus

The uterus is a major female reproductive organ where the fetus develops during pregnancy. In the context of a C-section, the script describes the uterus as the final target organ that the surgeon will access after making several incisions and cuts through various layers of tissue.

💡Microbiome

The microbiome refers to the collection of microorganisms that live on and in the human body, playing a crucial role in health. The script briefly touches on the impact of C-sections on an infant's microbiome, noting that babies born via C-section may have a different microbiome profile compared to those born vaginally, which could potentially have long-term health implications.

Highlights

Cesarean sections (C-sections) are increasing worldwide, with a prevalence of 20-30% of all births.

C-sections are not a one-size-fits-all procedure; they depend on various factors including the doctor and the circumstances.

The type of incision in a C-section can vary based on whether it's an emergency or planned, and the woman's history with C-sections.

Anatomy of the pelvic region is crucial for understanding where incisions are made during a C-section.

The incision location is typically 2-5 centimeters above the pubic symphysis and is influenced by the anterior superior iliac spine (ASIS).

C-section incisions initially cut through the superficial layers of the abdomen to avoid muscle and reduce recovery time.

Blunt dissection is used to minimize blood vessel damage and promote healing.

The rectus sheath, a connective tissue layer, is an important landmark during a C-section.

The Linea Alba, a fibrous structure in the center of the abdomen, is the target for the second cut in a C-section.

After cutting through the Linea Alba, the peritoneum, a thin membrane, is encountered.

The uterus is accessed after navigating through the peritoneum during a C-section.

The incision on the uterus is typically transverse and positioned where the infant's head is located.

After the birth, the uterus is stitched closed, and its position within the abdominal cavity is adjusted.

C-section techniques vary in how they handle the closure of the peritoneum and subcutaneous fat.

The final step of a C-section is suturing the integument, which includes the epidermis and dermis.

Historically, C-sections were only performed to save the baby's life due to high maternal mortality rates.

Recent studies are uncovering the impact of C-sections on an infant's microbiome, which differs from that of vaginal births.

C-section born infants have a different microbiome profile, more similar to the mother's skin and the operating room environment.

Transcripts

cesarean sections or c-sections are on

the rise and they have been for many

years now there's multiple reasons as to

why that's true we can't just say it's

because women are electing to get them

more frequently or that more emerging

conditions are occurring that are

forcing the c-section that said though

if you look at the statistics worldwide

which do vary by country it's around 20

to 30 percent of all births are

c-section so what we want to do in this

video is illuminate some of the mystery

behind the procedure itself we're gonna

look at the exact issues that are being

cut through and get an idea of what she

can expect during a c-section let's do

this

first of all there is no universal

procedure for a c-section the type of

procedure that's performed depends on a

variety of factors including the doctor

as well as the circumstances with which

it needs to be performed such as is it

an emergency section is this designed to

save mom and baby's life or is this a

planned c-section and this woman

received multiple c-sections prior to

that so many factors come in to the

exact type of incision that's gonna be

made but at the end of the day there are

a lot of commonalities that modern

techniques share and that's what I want

to show you today so what we're gonna do

is jump on over to the skeleton and look

at some skeletal Anatomy that'll give

you an understanding of the basic layout

and area that they're going to be

cutting into during these procedures and

this is a real human skeleton pelvis now

obviously we've made a few adjustments

such as the metal and the paint that

illustrates the muscle attachments but

it's gonna give us a really good idea of

the landmarks that are in the area as

they're making their incision and again

the incision really does differ

depending on the procedure they go with

but more or less they're gonna go

anywhere from two to five centimeters

above this area here called the pubic

symphysis to see this piece of cartilage

this piece of cartilage connects these

two pubic bones we call that the pubic

symphysis so the go just a few

centimeters up and then they're also

going to be going based off of these two

landmarks here called the anterior

superior iliac spine or ASIS so they're

gonna go a couple centimeters in mediate

in the medial direction make their

transverse or curvilinear incision and

then stop another couple centimeters

before they were to reach that ASIS

again though it does depend on which

procedure they end up doing the height

they make this initial transverse cut so

when they make this initial transverse

cut in the abdomen they're only cutting

through the superficial layers of the

abdomen or the integumentary system so

this is the epidermis dermis and

hypodermis or the subcutaneous tissue

which is comprised mainly of fat cells

and they do this because they don't want

to cut into the muscle underneath

because that is going to increase

recovery time dramatically and can be a

huge risk of complications so what

they're going to do is they make that

and then they're gonna start tearing the

tissue away from itself and this sounds

kind of aggressive but the idea here is

this will lessen recovery time as well

you see if you use a sharp tool such as

a scalpel for everything you're doing

you've increased the likelihood of

severing blood vessels and just making

it much more difficult for that tissue

to heal so they're gonna use their hands

and blunt ends to an instrument as much

as possible to try and just reveal the

deeper tissues which are going to be

connective tissue and muscle because

they're going to need to make a second

cut so once they've kind of revealed and

enough space they should be able to see

what's going to be called the rectus

sheath and the rectus sheath is just a

connective tissue layer that surrounds

the rectus abdominis muscle and we can

see that right here with this particular

cadaver so what you'll notice is we have

the umbilicus or the belly button left

on and you can also see that so we have

the epidermis dermis

and then deep to it you can see all this

fatty tissue it's padding tissue is that

subcutaneous tissue that they're going

to be cutting through so this is kind of

nice you can see all the layers that

they would be cutting through as they do

that really low transverse cut which is

often referred to as the bikini line cut

but once they do that and they've

exposed enough of the area they can see

this tissue here called the rectus

sheath so all this white connective

tissue this is called the rectus sheath

and it just lies just on top of the

muscle tissue the rectus abdominus so

we've kind of cut away some of the

rectus sheath to reveal the rectus

abdominus on this side and left it

intact here so what the rectus sheath is

is it's a tendon it's a tendon that

emerges from the obliques which are on

the sides and you can see the obliques

here so we can see the fibers of

external oblique and then I can kind of

flip that over and we can see the fibers

of internal oblique and then I can flip

that yet again and we can see the fibers

of transversus abdominus so in between

these layers is a bunch of collagen

fibers and what will happen is they will

then branch out and envelop the rectus

abdominus in this connective tissue

layer that we call the rectus sheath so

when the obliques contract it kind of

tighten

but compresses the abdomen so what's

interesting too is when all of those

connective tissues live connective

connective tissue layers converge they

converge right in the center and they

form this white line that goes right

down the center of the abdomen called

the Linea Alba and it really is a white

line that's what Linea Alba means we can

see that right here so all of this is

the Linea Alba going up towards that

sternum and this is a gap between the

muscles and this is what they're looking

for when they start making their the

second cut they want to make that cut

through the Linea Alba so they're not

cutting through muscle tissue so they

will reveal away or kind of cut away or

remove part of that rectus sheath just

so they can see enough of the Linea Alba

to then cut or tear their way through

again depends on the specific technique

they use but once they do that they're

then gonna meet another layer that's

called the peritoneum and if I flip this

over we can see what this peritoneal is

going to look like and that's what this

is right here this is all the parrots

Neum on the inside of the rectus

abdominus so then they're going to make

their way through this and that's when

they would run into the uterus so what

we're gonna do is jump on over to a

different cadaver so we can see the

uterus and get a better understanding of

the next type of incisions that are

gonna be made as you can see the rectus

sheath is completely intact on this

cadaver and we've also made an incision

that goes around the lower aspect of the

abdomen and I want to be very clear that

is not at all what they do during the

c-section that's something we did in

order to be able to see the underlying

Anatomy but remember there's this white

line here called Linea Alba so if we had

removed that rectus sheath you'd be able

to see that Linea Alba much more clearly

and what they do is they make an

incision in going vertically through

that Linea Alba and then separating the

two rectus abdominus muscle heads and as

they did that does it reflect this back

you can see that parrots neum that I

mentioned earlier they'd have to go

through this next because I pull this

back we see a giant piece of tissue that

you really wouldn't have to worry much

about during a normal c-section called

the greater omentum this is a fatty

apron like tissue that drapes over the

intestines you have to remember in a

full-term pregnancy

this thing would have kind of gotten

pushed out of the way so they really

don't have to do much wrestling with

this but it's a really interesting piece

of tissue but I'm just gonna fall back

and we meet the small intestines and

again the small intestines would also be

kind of out of the way you see the

uterus would have pushed them to the

side and they would have also slipped

behind the uterus in most cases so as I

pull these small intestines out of the

way we can see the uterus and that's

what this is right here

and obviously it's smaller I mean she

was in her mid 90s so we can't expect

her to have the uterus the size of a

full-term pregnancy this is pretty cool

we can also see an ovary right here on

the side as it connects to this uterine

tube but this uterus just picture is

they would open this up they've cut

through the peritoneum they would see

this uterus just jetting out like this

so what they would do and again it

depends on the procedure they'll make a

cut

typically the incision is going to be

transverse again and it's going to then

just be in the rough position of where

the infant's head is so they can then

birth the infant as well as the placenta

right they have to get that placenta and

amniotic sack and everything else out

not just the infant but as they bird

that they would then stitch that uterus

closed and sometimes some procedures

they even pull the uterus out and so as

they stitch it they have to come up put

it back in and rotate it and put it into

this cavity that you're seeing right

here but again it would be much much

bigger and then the intestines and

everything will kind of fall around it I

mean it's obviously the uterus is going

to be smaller now that it doesn't have

an infinite side of it but it's still

gonna be pretty big but they don't

really do much putting of the tissues

back because they really only have a

small window the body will take care of

most of that by itself but what they

will do depending on thinking this

depends on the technique sometimes they

will actually if I put this back some

techniques will stitch and suture this

peritoneum closed others won't some

techniques will actually stitch the

subcutaneous fat closed and others won't

it really depends but what they have to

do once they've put all the tissues back

they'd put the uterus in place they have

to suit your shut the integument the

epidermis and the dermis and when they

do that at that point the c-section

is done it's really interesting to think

about just how far we've come with

c-sections historically they were only

performed in order to save the baby's

life because they became it's such a

high mortality rate for the mother they

didn't want to do it unless they

absolutely had to

but again nowadays like I mentioned

earlier we're hovering around that 20 to

30 percent average worldwide it's

amazing to see just how far we've come

now there's something else I do want to

briefly mention and that is something

that we're just starting to learn and

understand the effect on the microbiome

of the infant as its form by a c-section

you see normally as the infant is born

through the vaginal canal mom's vaginal

secretions which are coated in good

bacteria will then coat the infant the

infant will even swallow that and it

will help create a different microbiome

population eventually inside of the

digestive tract but when they're being

born by c-section we're finding a

completely different microbiome profile

and that's going to be more similar to

the skin on the mother as well as even

the operating room itself with which the

infant is born now we're still not sure

of what consequences this will have

later on in life if any at all but it's

so interesting to note that there's just

differences in even the microbiome based

on whether it's a c-section or a vaginal

birth I know for me I'm very interested

to see where this will go as we learn

more throughout the years but hopefully

this gave you a better understanding as

to what's going on with a c-section or

at least the anatomy that they're

cutting through as they perform it be

sure to LIKE comment subscribe if you

haven't already and I will see you in

the next video

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