51. GI anatomy

Question 1

What is the peritoneum?

Answer 1

Two layers (parietal and visceral) of squamous epithelium (mesothelium) and connective tissue that allow the passage of blood vessels and lymph nodes to the abdominal viscera.

Question 2

Describe the parietal peritoneum?

Answer 2

Lines the internal surface of the abdominopelvic wall. It is derived from somatic mesoderm in the embryo

pain from the parietal peritoneum is well localised due to innervation from abdominal wall. Parietal peritoneum is sensitive to pressure, pain, laceration and temperature.

(just like the pleura)

Question 3

Discuss the visceral peritoneum

Answer 3

It is derived from splanchnic mesoderm in the embryo.

The visceral peritoneum has the same autonomic nerve supply as the viscera it covers.

Pain from the visceral peritoneum is referred to areas of skin (dermatomes) which are supplied by the same sensory ganglia and spinal cord segments

Invaginated parietal peritoneum (like a balloon)

Question 4

what is a peritoneal adhesion?

Answer 4

damage to the peritoneum due to infection or injury.

Such adhesions can result in pain and complications such as volvulus, when the intestine becomes twisted around an adhesion resulting in a bowel obstruction.

Question 5

What organs are retroperitoneal organs?

What organs are primarily retroperitoneal organs

Answer 5

S
A
D
P
U
C
K
E
R

Primary peritoneal-

Question 6

What organs are retroperitoneal organs?

What organs are primarily retroperitoneal organs

Answer 6

S Supradrenal glands
A Aorta/IVC
D Duodenum
P Pancreas (minus the tail)
U Ureters
C Colon (minus transverse)
K Kidneys
E oesophagus
R Rectum

Primary peritoneal- developed and remained outside peritoneum. Oesophagus, rectum and kidneys

Question 7

What are peritoneal reflections?

Answer 7

highly folded complex structures that provide specific functions.

Mesentery
Greater and lesser omentum
periteneal ligaments

Question 8

What is the mesentery?

What are the peritoneal ligaments?

Answer 8

mesentery- double layer of visceral peritoneum, pathway for nerves,vessels and lymphatics.

ligaments- double fold of peritoneum that connects viscera together or connects viscera to abdominal wall.

Question 9

Describe the omentum

Answer 9

Greater Omentum- abdominal policemena. travel from greater curvature of stomach to transverse colon

Lesser Omentum- lesser curve of stomach to proximal part of duodenum. Consists of two parts the hepatoduodenal ligament and the hepatogastric .

Question 10

What is the peritoneal cavity?

What is contained in peritoneal fluid?

Answer 10

The potential space between parietal and visceral peritoneum. Normally contains peritoneal fluid

Water, electrolytes, leukocytes and antibodies

Question 11

How do you divide the peritoneal space?

Answer 11

Greater and lesser sac

Question 12

Explain the greater sac?

Answer 12

The larger portion of the peritoneal cavity, further divided into supra-colic compartment and infra-colic compartment

Question 13

What are the paracolic gutters?

Answer 13

connections between supra colic and infra colic compartments. Contains a potential for pus and fluid to gather

Question 14

Discuss the lesser sax

Answer 14

Lies posterior to the stomahc and lesser omentum

Connected to the greater sac by the epiploic foramen

Question 15

What is the lowest area of the peritoneal cavity in males?

Answer 15

Rectovesical pouch- males

rectouterine puch (douglas)-females
Vesicouterine pouch (uterus and bladder)

Question 16

What is the porta hepatasis?

Answer 16

Where the hepatic ducts and neurovascular structures enter and exit the liver.

Question 17

What are the border’s of calot’s triangle?

Answer 17

common hepatic duct- medial
Cystic duct- inferior
inferior surface of liver- superior

Question 18

What are the contents of calot’s triangle?

Answer 18

Right hepatic artery
Cystic artery
Lymphatics (lymph node of lund (first lymph of gallbladder)

Question 19

What is all the big fuss about calot’s triangle?

Answer 19

There may be anatomical variation and therefore the surgeon needs to identify the contents and borders

Question 20

What is the inguinal triangle?

Answer 20

Hesselbach’s triangle- weakening in the abdominal wall may be a site for hernia

Question 21

What is the gubernaculum?

Answer 21

Fibrous cord that decides the descent of the testicles /ovaries from the abdominal wall down

Goes on to form ovarian ligament and round ligament of uterus

Question 22

What are the boundaries of the inguinal canal?

Answer 22

Anterior wall-aponeurosis of external oblique, internal oblique

Posterior wall- transversalis fascia

Roof- internal oblique, transversus abdominis

Floor- inguinal ligament

Question 23

What are the contents of the inguinal canal?

Answer 23

spermat cord (males)
Round ligament (females)
Gneital branch of genitofemoral nerve
ilioinguinal nerve