Abdominal Wall & Peritoneum

Abdominal wall

Objectives:• To know the anatomy of abdominal

wall( ant& post).• Blood supply nerve supply and lymph

drainage• To understand the anatomy of the inguinal

canal• To list common types of hernia

Abdomen is a closed cylinder with a musculo-skeletal wall.

Inside are the wall are the liver, intestines, kidneys, etc.

Abdominal Muscles Increase Intra-abdominal pressure

Remember Valsava?

Abdomen defined by diaphragm above, pelvic brim below, and vertebral bodies ribs and muscles posteriorly, and laterally.

To get in the abdominal cavity you must go through skin, 2 superficial fascias (fatty and membraneous). 3 muscles layers (or one), transversalis fascia, parietal peritoneum.

MUSCLES OF THE ANTEROLATERAL ABDOMINAL WALL

LINEA ALBA

TENDINOUSINTERSECTION

RECTUSABDOMINIS

INGUINAL LIGAMENT

TRANSVERSUS ABDOMINIS

INTERNAL OBLIQUE

EXTERNAL OBLIQUE

APONEUROSIS OFEXTERNALOBLIQUE

SUPERFICIALINGUINAL RING

MUSCLES OF THE ANTEROLATERAL ABDOMINAL WALL

RECTUS SHEATH

APONEUROSES

TA

IO

EO

BELOW THE ARCUATE LINE ALL APONEUROSES PASS IN FRONT OF THE RECTUS ABDOMINIS

ABOVE THE ARCUATE LINE THE APONEUROSIS OF THE INTERNAL OBLIQUE SPLITS TO ENCLOSE

THE RECTUS ABDOMINIS

Vessels of the Anterolateral Abdominal Wall

Internal thoracic vessels

Inferior epigastric vessels

Superior epigastric vessels

Nerves of the Abdominal Wall—Ventral Rami of T6 to L2

MUSCLES OF THE ANTEROLATERAL ABDOMINAL WALL

EXTERNAL OBLIQUE

BILATERAL ACTION:ASSISTS RECTUS ABDOMINISIN FLEXING VERTEBRALCOLUMN, COMPRESSING ABDOMINAL WALL, ANDINCREASING INTRA-ABDOMINAL PRESSURE

UNILATERAL ACTION:AID BACK MUSCLES INROTATION ANDLATERAL FLEXION

NN. = T7-T12

INTERNAL OBLIQUE

NN. = T7-T12, L1

MUSCLES OF THE ANTEROLATERAL ABDOMINAL WALL

RECTUS ABDOMINIS

RECTUSABDOMINIS

BILATERAL:FLEXION OF VERTEBRALCOLUMN, COMPRESSION OF ABDOMEN, INCREASE IN INTRA-ABDOMINALPRESSURE

UNILATERAL:ASSISTS BACK MUSCLES IN LATERAL FLEXION AND ROTATION

NN. = T7-T12, L1

Psoas and quadratus lumborum form posterior wall.

Psoas + Iliacus = Iliopsoas—Most Major Hip Flexor—Crosses under Inguinal Ligament with Femoral Nerve, and External Iliacs (become Femoral a and v.

Inguinal Ligament—inferior border of aponeurosis of external oblique muscle—attaches to ASIS and pubic tubercle

*

* Superficial Inguinal ring, a weak spot through which abdominal contents may extrude-direct inguinal hernia.

Deep Inguinal Ring—Pushes through transversalis faciaInginal Canal from deep ring (under ext. oblique) to superfical inguinal ring (where hernias puch out)

What’s indeed the parietal peritoneum?

Liver

Gall Bladder

Stomach

Ascending Colon

Small intestines

Greater Omentum—an apron from the stomach to the transvers colon.

The Abdominal CavityThe Abdominal Cavity

DOUBLE-LAYERED FOLDS OF PERITONEUMTHAT SUSPEND THE VISCERAL ORGANS.

PROVIDE A NEUROVASCULAR CONNECTION BETWEEN THE ORGANS AND THE BODY WALL

MESENTERIES

““The Mesentery”The Mesentery”

The Mesentery

• Greater omentum and transverse colon reflected—pulled up.

Figure 22.6c

The Mesentery attaches to the posterior wall.

Ileo-Colic junction

Duoduodnal-Jejunal junct

Duodenum

begins

Intraperitoneal Abdominal Organs derived from foregut (B) Intraperitoneal Abdominal Organs derived from foregut (B) have a dorsal and ventral mesentery. Midgut derived organs have a dorsal and ventral mesentery. Midgut derived organs

(A) lack a ventral mesentery.(A) lack a ventral mesentery.

A

A

B

B

Parietal peritoneum – Parietal peritoneum – serous membrane lining the abdominal serous membrane lining the abdominal cavity (space between)cavity (space between)

Visceral peritoneumVisceral peritoneum – – serous membrane covering the internal organsserous membrane covering the internal organs

Right and Left Colic Flexures

Some Organs Lose Their Mesentery Some Organs Lose Their Mesentery and Become Retroperitonealand Become Retroperitoneal

INTRAPERITONEAL VS.

RETROPERITONEALINTRAPERITONEAL ORGANS ARE ALMOST COMPLETELY COVERED WITH VISCERAL PERITONEUM

– THEY are suspended or protrude “in” into the peritoneal cavity, but are not actually in it.

RETROPERITONEAL ORGANS ARE LOCATED between the

paeietal perinoneum and the body wall itself. -They may be partially covered by parietal peritoneum

Subperitoneal—some organs lie below the peritoneum in the pelvis, e.g. The uterus and bladder.

PARIETAL PERITONEUM—Blue areaPARIETAL PERITONEUM—Blue area

MESENTERY PROPER

TRANSVERSEMESOCOLON

NOT SHOWN: MESOAPPENDIX, SIGMOID MESOCOLON

The Adult MesenteriesThe Adult Mesenteries

LESSER OMENTUM –A double layer of peritoneum extendingfrom the porta hepatisof the liver to the lessercurvature of the stomachand the beginning of the duodenum

GREATER OMENTUM –a double layer of peritoneumattached to the greatercurvature of the stomachsuperiorly and the transverse colon inferiorly; it hangs down like a fatty apron over theabdominal viscera

GREATER AND LESSER OMENTA

LESSER SAC OROMENTAL BURSA

GREATER SAC –SUPRACOLIC

GREATER SAC –INFRACOLIC

TWO PERITONEALSACS

TRANSVERSEMESOCOLON

Rotation of the Stomach Forms the Lesser Sac of the Rotation of the Stomach Forms the Lesser Sac of the Peritoneal Cavity and Starts to Form the Greater OmentumPeritoneal Cavity and Starts to Form the Greater Omentum

LOCATION OF THE SPLEEN

SPLEEN

The Peritoneum

The Peritoneum

The parietal peritoneum

The visceral peritoneum

The peritoneal cavity

kidneys

ureters

suprarenal glands

duodenum

pancreas

aorta

inferior vena cava

nerves

ascending colon

descending colon

The retroperitoneal space

The Peritoneum

The parietal peritoneum

The visceral peritoneum

The peritoneal cavity

The visceral peritoneum

The peritoneal cavity

1. The peritoneal ligaments

falciform ligament

ligamentum teres

median umbilical ligament

medial umbilical ligaments

lateral umbilical ligaments

2 layer folds of the peritoneum

1. The peritoneal ligaments

2. Lesser and Greater Omenta

3. The mesenteries

2. Lesser and Greater Omenta

Lesser and Greater Omenta

Lesser Omentum

hepatogastric ligament hepatoduodenal ligament

the epiploic foramen(of Winslow)

Greater Omentum

3. The mesenteries

The mesenteries

transverse mesocolon

sigmoid mesocolon

mesentery of the small intestine

Contents ?

Lesser Sac

Other Ligaments

Lesser Omentum

Greater Omentum

falciform ligament

ligamentum teres

phrenicocolic ligament

gastrocolic ligament

gastrophrenic ligament

gastrosplenic ligament

hepatogastric ligament hepatoduodenal ligament.

Lienorenal ligament

Lesser Sac

Lesser Sac

Lesser Sac

(Omental Bursa)

Morison’s pouch

left subhepatic space Vestibule

Superior recess

Lesser Sac

epiploic foramen (of Winslow)

Epiploic foramen (of Winslow)

Ant: hepatoduodenal ligament

Post: inferior vena cava

Sup: caudate lobe

Inf: first part of the duodenum

The supra-colic compartment

Peritoneal cavity

Greater sac

Rt. anterior subphrenic space Lt. anterior subphrenic space

Rt. posterior subphrenic(Rt. Subhepatic)

Morison’s pouch

left subhepatic Space(Lt. posterior subphrenic) Vestibule

Superior recess