Antero-lat Abd Wall Complete)

8/8/2019 Antero-lat Abd Wall Complete)

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ANTERO-LATERAL

abdominal wall

& INGUINAL

REGION

Special thanks to:

AMAR

KAMAL

ZULKHAIRI

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We will start talking about rectus sheath which is basically a pocket

made of fibrous tissue, houses the rectus abdominis muscle, the

pyramidalis muscle, blood vessel and nerve that we are going to talk about

in a minute. This pocket has anterior and posterior walls. In this side

(refer to slide 15) we see the anterior wall, in this line we remove the


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abdominal wall and rectus abdominis muscle so, we can see now is the

posterior wall of the rectus sheath.

As you can see now, the anterior wall is longer than posterior wall

because it terminates earlier and the line of termination, we call it the

arcuate line. So what happens at this line?? I told you that the pocket is

made anteriorly by the aponeuroses of the external oblique and half of

the aponeuroses of internal oblique. The posterior wall of the sheath is

made of the aponeurosis of the transversus abdominis muscle and half of

the aponeurosis of internal oblique. What happen at the level of the

arcuate line; all of the aponeuroses they go anteriorly. It is a landmark

for us to identify the inferior epigastric artery. Inferior epigastric

artery enters the rectus sheath, anterior to the arcuate line.

Here, at higher level, you see, the aponeuroses, they split and go anterior

and posterior to the rectus abdominis. At the level of arcuate line or

below, all of them they go anteriorly.

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(refer books Richard S.Sneil page 157)


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y Above the costal margin, the anterior wall is formed by the

aponeurosis of the external oblique. The posterior wall is form by

the thoracic wall.

y Between the costal margin and the level of anterior superior iliacspine, the aponeurosis of the internal oblique splits to enclose the

rectus muscle; the external oblique aponeurosis is directed in front

of the muscle; and the transversus aponeurosis is directed behind

the muscle.

y Between the level of the anterosuperior iliac spine and the pubis,

the aponeurosis of all three muscle form the anterior wall. The

posterior wall is absent, and the rectus muscle lies in contact withthe fascia transversalis.

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What is the level of the arcuate line? Anterior superior iliac spine.

So we have now a sac (the rectus sheath) and we have structure within it.

(Refer slide 20) we have 2 muscles, 4 blood vessels and 6 nerves (2-4-6)

The 2 muscles are: rectus abdominis and small muscle called the

pyramidalis (its a triangular muscle found at the lower part)

We have 4 blood vessels: superior and inferior epigastric arteries,

superior and inferior epigastric veins.

Then 6 nerves which are: intercostal nerves from T7- T11 (5 nerves) and

subcostal nerve in T12.


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Blood supply of Abdominal Wall (refer page 158 from the book Richard

S.Sneil)

Superior Epigastric Artery : It is a continuation of internal thoracic

arteries. We said that internal thoracic arteries split at 6th intercostal

space leading to two branches; superior epigastric and musculophrenic

arteries.

# musculophrenic artery stays in the thorax, the superior epigastric

artery leaves the thorax and enters the abdomen. It leaves by passing

behind the sternal and the costal origin of the diaphragm and then, it

passes posterior to rectus abdominis muscle.

Inferior Epigastric Artery : It is a branch of external iliac

artery. External iliac is found in the groin region so this artery will go

upward and medially until it anastomose with Superior Epigastric

Artery.

In addition to those arteries we have Post. Intercostal Artery (10th

&11th)& Subcostal Artery (12th) which are branches from thoracic aorta.

Also we have also Lumbar Arteries which are branches of the abdominal

Aorta.

And Deep Circumflex Iliac Artery, its a branch of external iliac

artery. It goes lateral and backward.

This is just a picture to show what were talking about. Superior

epigastric, inferior epigastric. Deep circumflex is presented in dotted

lines because it goes backward or at least lateral not medially.


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Nerves of Abdominal Wall (refer page 158 from the book Richard

S.Sneil)

Nerves within the rectus sheath plus the 1st lumbar nerve. We have

Lower intercostal nerves, subcostal nerves and 1st Lumbar nerve which

does NOT enter the rectus sheath.

Lower intercostals nerve consist from T7-T11 and subcostal nerve

located at T12

The 1st lumbar will split into iliohypogastric nerve and ilioinguinal nerve.

Inguinal regions


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We mentioned in the last lecture about inguinal ligament, we said it is the

thickening of the lateral margin of the aponeurosis of external oblique.

It extends between the anterio-superior iliac spine and pubic tubercle.

The arrangement of fascia and muscle aponeurosis, they form an obliquecanal at the lower margin of the abdomen. (can see figure A in page 106

in Grants Anatomy).

This inguinal region or inguinal canal is used for the muscle of spermatic

cord in male or the round ligament of the uterus in

female. Its considered an area oblique? What does

that mean? We said we have a muscular wall or

abdominal wall made of muscle, aponeurosis and etc

that hold the abdominal viscera and structures. If

you have an opening, then this is the area of

obliqueness, because under pathological condition

the structure can escape from this opening, we call

this hernia.

So, where this canal located? This is the inguinal

canal, it is located superior and medial to the

inguinal ligament. This dark, white colour here is

inguinal ligament. It runs oblique in inferomedial

direction. It has spermatic cord in male and round

ligament of uterus in female plus the ilioinguinal

nerve in both sexes.

Since were talking about the canal, there are 2

openings. Superficial opening (in the last lecture) we

said it is due to a defect in the aponeurosis of

external oblique.


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Since there is superficial opening, there will be deep opening. The deep

opening is the entrance to the canal. It lies above the middle of the

inguinal ligament. So, what does that mean? It means the canal is not the

same length of the inguinal ligament. No, it starts at the middle of theinguinal ligament. So, its shorter than the inguinal ligament, and its an

oval opening in what layer of the transversalis fascia?

So, here were looking at the abdominal wall, we remove the skin and

superficial fascia. What can I see? I can see the aponeurosis of the

external oblique, that triangular defect of opening which is the

superficial inguinal ring or superficial inguinal opening. And through

which, (for a male) spermatic cords passing.

This is superficial. In order to find the deep, I should remove the layers,

layer by layer, to find the first sign which structures in the abdominal

exitto enter internal inguinal region. So we remove the external oblique,

what we have here is the internal oblique. We remove the internal

oblique, we see the transversus abdominis muscle. We remove that

muscle, we are left now with the transversalis fascia. I remove this layer

now, I would see the peritoneum and the abdominal structures.

So, in this layer, I should find the deep inguinal ring, which is here,

slightly pass out (x sure) the inferior epigastric artery. The canal is

made. The layer that I just remove. If you stack them back, you will end

up with a tunnel, within our inguinal region, this tunnel is the inguinal

canal. So, I already said that the superficial inguinal ring triangular exit.Within what muscle? Within what aponeurosis? The external oblique. The

lateral & medial borders, we called them the crura which is the

attachment site for external fascia of the spermatic cord.


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If you guys see the cadaver, you will not be able to see an opening &

structure passing through the opening. Why? Because structure that

pass through the opening is attached to the border of the opening. This

why it is sometimes disappointing, that you cant identify this ring in acadaver.

Again, this picture is just emphasizing what I told you about the

triangular exit in which the spermatic cord passes. It has structures

going back and forth between the abdomen and scrotum in the testis.

Now, lets try to define the walls to the canal. We have a root (superior

wall), floor (inferior wall), anterior & posterior. The anterior wall, as youcan see from the 1st lecture, it is made by external oblique aponeurosis.

And it is reinforced in the lateral third by internal oblique aponeurosis.

The posterior wall is made by tranversalis fascia, the deepest layer that

Ive just show you. Its reinforced medially by insertion of internal

oblique & transversus muscle. The tendon, conjoint tendon that result

come from the margin of the fibers, from the internal oblique and

tranversus muscle we call it, the conjoint tendon.

Look at the anterior wall. The anterior wall has a weak site. Where is it?

It is at the site of opening. So to protect the structures from escaping,

from herniating, we should strengthen the posterior wall. This is why the

posterior wall is reinforced medially. In this region, the posterior wall is

stronger. It is reinforced by the conjoint tendon.

What about the posterior surface? The posterior surface is weak in this

region because it is the region of the deep inguinal opening. To

compensate for that, we should strengthen the anterior wall. This is why

the anterior wall is reinforced in the lateral third in this region by the

internal oblique aponeurosis. Do you get the idea? Am I clear?


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When we have an opening in one wall, we

should compensate in the other wall by

adding a layer of protection. I mention the

conjoint tendon, result from the margin ofaponeurosis of internal oblique &

tranversus abdominis muscle. They merge

together in the midline. Their aponeurosis

make one common tendon for them, we

inserted in the pubic area. This tendon, we called it the conjoint tendon.

How its located? Regarding the superficial ring ,its posteromedial. So,

its in the medial site and posteriorly. So, its a part of the posterial wall.

Now, we move to the root or the superior wall of the inguinal canal. This

picture itself is mandatory, you can see that this is the space where the

canal will be, the fibers from internal oblique and tranversus muscle, they

make an arch surrounding the canal. So, the superior wall of the inguinal

canal is from the arching fibers of internal oblique and tranversus

abdominis muscle. So, its muscle fibers. Were not talking aboutaponeurosis regarding the root anymore. The flow is made of the inguinal

ligament and the lacunar ligament. What is the lacunar ligament? Its the

medial continuation of the inguinal ligament. It will be obvious in this

picture.

So, this is the inguinal ligament. It stays from the anterior superior iliac

spine until the pubic tubercle. It does not

end there. It ends as an inguinal ligament

but it continuous backward as the lacunar

ligament. So, to memorize, we have superior

wall, inferior, anterior and posterior. Lets


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start from superior wall and move anti-clockwise. This is the arrangement

of the walls. The superior one is made of muscle.waba3din!! (Dr gets

anger to the students that are speaking in the class. So, ma3as salamah)

So the superior wall is made of muscle, the arching fiber of internal

oblique and transversus abdominis muscle. The anterior wall is made of

aponeurosis which is the aponeourosis of what? Of external oblique.

Aponeurosis is a tissue. The inferior wall is made of ligament, the inguinal

ligament and the lacunar ligament. The posterior wall is made of

tranversalis fascia and conjoint tendon. It should help you remember.

The orientation. (MALT)

We mention the spermatic cord that passes through the inguinal canal in

males. So, what is this cord made of? It is made of ductus (vas) deferens

which a tube that collects the sperms from the testis and take it to the

urethra. We have testicular artery, artery to vas deferens and

cresmateric artery . So we have blood vessels. We have a vein, a venous

plexus (pampiniform plexus) that collects the blood from the testis and

merge just before leaving the deep inguinal ring. It merges in one way, we

call it the testicular vein. We also have autonomic nerve fibres

(sympathetic). We have genital branch of genitofemoral nerve that

supply the cresmaster muscle. We have lymphatic vessels within the cord.

(This testicular lymph vessels ascends through the inguinal canal and

pass up over the posterior abdominal wall to reach the lumbar lymphnodes on the side of the aorta at the level of the first lumbar vertebra.

from the textbook)


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What is the cord made of?How many layers does it have?

You can see the first layer of the cord, we call it external spermatic

fascia, it is derived from external oblique muscle (attached to the

superficial inguinal ring). If we remove this layer, we will see

cresmasteric fascia, it is derived from internal oblique muscle. Well hear

the name cresmasteric muscle and cresmasteric fascia, why? Because its

actually a combination of both, it is a muscle fibre embedded within

fascia. If we remove the cresmasteric fascia, we will end up with internalspermatic fascia, it is derived from transversalis fascia. (attached to the

deep ring). Now, the idea I told you, that the opening actually in the

cadaver, we cant recognise theres an opening because the external

spermatic fascia is attached to the superficial ring, and the internal


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spermatic fascia is attached to the deep ring. So, it is not easy to

recognise there is a passage.

This define the cremaster muscle, it is derived from the internal oblique

muscle. The function, by contraction, it elevates the testis superiorly in

cold environment. In warm environment, it relaxes the testis and

descends in the scrotum, because the control of temperature is essential

for sperms survival.

During the development of the foetus, the testis in the scrotum is

formed inside the abdominal cavity, and it descends to the scrotum

during development. And this descending fails, we will end up with

sterility because the sperm will never survive.

We already talked about the covering fascia of the spermatic cord. This

is just in males. In female, we dont have spermatic cord, but we have

round ligament. So, instead of saying external spermatic fascia, well say

external covering of round ligament. Cremasteric fascia and we have

internal covering of round ligament.


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As we said, inguinal canal represents an area of obliqueness within

abdominal wall. Why? Because it exposes abdomen for hernia

Hernia (rupture), when a structure get dislocated through an opening to

another location or protrusion of abdominal organs to outside through

abdominal wall weakness. If you remember, this is a diaphragm of the

stomach when part of the stomach goes up, herniated to the thorax.

Now, same idea might happen in the inguinal region. But, in this case, the

structure will pass through inguinal ring.

We have two types of inguinal hernia; indirect or direct inguinal hernia.

The indirect; it means the structure, lets say, part of the intestine will

leave the abdomen and go through the inguinal canal.

The direct; it will leave the abdomen but it wont go through the inguinal

canal. But we havent seen that(x clear) the tone of muscles in the

abdomen will be lost and we have a protrusion a sac pouching part of theabdomen. The picture will tell you more.


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- indirect hernia

- part of the small intestine escape the abdomen through the inguinal

canal and in some cases will enter the scrotum- Chances in males is 20 times than female, because the inguinal canal

in males is larger and more prominent.

- direct hernia

- the muscle tone (constant minimum amount of contraction of the

muscle all the time that give us the constant shape) will lose and

part of abdomen might protrude out pouch as in this case.


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- Most common area is the inguinal triangle area which is made by

these three structures. The protruding structure will form an

inguinal sac by structure pushing the transversalis fascia.

- Structure will not enter the scrotum (it helps in the diagnosis)

Surface anatomy

For student like you, abdomen is very large. So, I want to describe a

structure, I should have specific terms to know a specific location.


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We will divide the abdomen into 9 regions. How? We will divide to 9

regions by having four lines or 4 planes.

Vertical planes, we call them midclavicular lines that pass mid clavicle to

mid inguinal ligament, on either side.

We have two horizontal lines, one, we call it subcostal line, its at the

level of 10th costal cartilage or it corresponds to the lumbar vertebra 3

(L3)

And we have transtubercular plane. It is a line that passes through theiliac tubercles, its at the level of lumbar 5 (L5)

By doing so, we end up with 9 regions. So, if a patient comes complaining

about pain in the abdomen and want the report,you will define whether

the pain is in this region or that region.

Each region of this has names. Lets start with the top one. We have

right and left hypochondriac areas. In the middle, we have right and left

lumbar areas. Inferiorly,we have right and left inguinal areas. In the

middle, the top one, we have epigastric area. In the middle, because it

has umbilicus, we call it umbilical area. And the lower one, we call it pubic

area or hypogastric area.

What you need to know is how we made these areas, their names and the

vertebra levels that Ive just mention to you.


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A simpler method to divide abdomen is by just dividing the abdomen to

four quadrants, by having a midsagittal line that passes through the

symphysis pubis (the joint between two pubic bones) and symphysis menti

(the mandible during the development, a practical aspect ya3ni, that

fuses in midline in the joint)

Also we have a horizontal line that we called it transumbilical plane. It

passes through umbilicus and it is at the level of intervertebral disc

between L3 and L4.

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*No comment will beentertained*

SEKALUNG PENGHARGAAN BUAT SEMUA YGTERLIBAT DLM PEMBUATAN

LECTURENOTENI. MOGAALLAHMEMBALAS JASA KALIAN DENGAN

GANJARAN YG LEBIH BESAR DIAKHIRATKELAK

INSYAALLAH, ALLAH YUSAHHIL UMURUNA

AMIN..

Antero-lat Abd Wall Complete)

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