Anatomy: Abdominal Cavity:

Peritoneum & GIT

4th Lecture of Second

Peritoneum

A serous membrane of 2 continuous layers that covers the abdominal organs

(G, To stretch or cover around )

Parietal: lining internal abdominal wall

Visceral: lining abdominal organs (viscera)

Peritoneal cavity: space between parietal & visceral layers

fluid filled reduce friction

* NO organs in peritoneal cavity

Abdominal Organs Relation to Peritoneum

Intraperitoneal:

completely covered by visceral peritoneum

e.g. stomach, spleen, jejunum, ileum

Retroperitoneal:

posterior (behind) the peritoneum

only partially covered with visceral peritoneum

e.g. pancrease, kidneys, ascending and descending colons

Peritoneal Cavity

2 parts

Greater sac:

main part of peritoneal

cavity

Lesser sac (omental bursa):

extensional cavity behind the stomach

allows free movement of stomach

connects with greater sac through epiploic foramen

Epiploic Foramen

Foramen of Winslow

Connects lesser sac to greater sac

Boundaries:

Ant.: portal triad

(p. vein, h.a., & bile duct)

Post.: IVC

Sup.: Liver (caudate lobe)

Inf.: duodenum (1st part)

Foramen of Winslow & Lesser Sac

Terms describing parts of peritoneum

Peritoneum has special names at specific regions:

omentum

mesentry & mesocolon

ligaments

OmentumBroad, double layered sheet of peritoneum that connects stomach

to another abdominal organ

2 parts

1. Greater Omentum:

Greater curvature of stomach

Down (like apron)

Ant. to S. intestine

Reflects up again

Ant. transverse colon

2. Lesser Omentum

Lesser curvature of stomach

& small part of dudenum (2cm)

Liver

Post. to it = lesser sac

* The free edge of lesser omentum is called: hepatoduodenal ligament

contains portal triad

Hepatoduodenal Ligament

Mesentery & Mesocolon

Mesentry:double layer of peritoneum connects small intestine to posterior abdominal wall

mesentry of small intestine

Mesocolon:double layer of peritoneum connects large intestine to posterior abdominal wall

transverse mesocolonsigmoid mesocolonmesoappendix

what about ascending and descending mesocolon !!??

Mesentery

&

Mesocolon

LigamentsDouble layer of peritoneum that usually attached to the liver

Falciform Lig.:

Attaches the liver to ant. abdominal wall and diaphragm

& ends by enclosing ligamentum teres

Hepatoduodenal Lig.:

The free edge of …?

1st 2 cm of duodenum to liver

Contents?

Gastro-Intestinal Tract (GIT) in Abdomen

• Esophagus (abdominal part, 1.25cm)

• Stomach

• Small intestine

• Large intestine

Esophagus

Enters through esophageal opening (T10)

Pass about 1.25cm before entering stomach

Ends at cardiac orifice (T11)

Stomach

*Intraperitoneal

4 regions

Cardia:

surrounds esophag. opening

Fundus

most sup. Part (dome shape)

Body

central part, largest

Pylorus (gate guard)

antrum & canal

Stomach

2 openings:

Cardiac orifice

esophagus stomach

(Physiologic sphincter)

Pyloric sphincter

stomach duodenum

(Anatomic & Physiologic)

Anat = thickened circular m. layer

2 curves:

greater (lf.) & lesser (Rt.)

Stomach

Muscular Wall of Stomach

Outer L??

Middle ??

inner ??

???

Small Intestine

(Read your text for detailed anatomy)

Duodenum (C-shaped)

Jejunum

Ileum

Duodenum* Retroperitoneal except over omental attachment (first 2 cm)

4 parts

1. Superior (1st):

From pylorus

Horizontal (vertebral level ??)

2. Descending (2nd):

Rt. To L2 & L3

Curves around head of pancreas

Receives bile & main pancreatic ducts

(Major papilla)

Duodenum

Ampulla of Vater & Major duodenal papilla

3. Horizontal (3rd):Ant. to IVCAt level of L3

4. Ascending (4th):At left side of L3Ends at duodenojejunal jxn. Forms flexure

The flexure is surrounded by a peritoneal fold

(lig. of treitz)

Small intestine enters peritoneum at the lig. of treitz

Jejunum & Ileum

* Intraperitoneal

Jejunum: (L, empty)

upper left half

wider & thicker

Ileum: (G, twisted)

lower right half

ends at ileocecal junction

(valve)

Peptic Ulcer

A discontinuation (erosion) in the mucosal covering in an area of the GIT (esophaguslarge intestine).

Most commonly in the ?

Causes:

1. Bacteria: Helicobacter pylori

~80% PUD

2. Drugs & Irritants:

NSAIDs (aspirin), smoking, alcohol

3. Hypersecretion of HCl

Rx.:antibiotics: only when ??

Amoxi. + Mitro.gastric acid inhibitors:

histamine receptor (H2) blockersAntacids: bufferDiet: irritants

Complications:GI-bleeding:

- erosion of a bld. Vessel - hematemesis (?)

Perforation:- erosion of the whole wall opening into abd. Cavity peritonitis & inflammation of adjacent organs* requires emergency surgical treatment

Large Intestine

Cecum & Appendix

Ascending (retro)

Transverse (intra)

Descending (retro)

Sigmoid (intra)

Rectum (in pelvic cavity)

McBurney’s Point

On a straight line : 1/3 from ant. sup. iliac spine 2/3 from the umbilicus

Corresponds to the base of the appendix

The incision site during appendectomy (removal of the appendix)