The Peritoneal Cavity

Question 1

With the patient in a supine position, where might fluid collect in the abdomen?

Answer 1

Posterior to the liver. (remember when we describe positions of structures we use the
anatomical position – even if the patient is lying flat (supine)).

Question 2

What embryological structure forms the ligamentum teres?

Answer 2

The umbilical vein, returning blood from the placenta to the liver.

Question 3

Where does the base of the appendix lie (surface marking and internally)?

Answer 3

2/3 of the way from the umbilicus to the anterior superior iliac spine, McBurnies point.

Question 4

Which parts of the bowel have a mesentery?

Answer 4

The first 1cm of duodenum, all of the jejunum and ilium, the transverse and sigmoid colon and the appendix.

Question 5

What structures form the portal triad?

Answer 5

Hepatic portal vein, bile duct, hepatic artery

Question 6

What is the (greater and lesser) omentum?

Answer 6

They are sheets of tissue covered on both surfaces with peritoneum and containing
fat, blood vessels, lymphatics and nerves.
The greater omentum attaches to the greater curve of the stomach and the posterior abdominal wall.
The lesser omentum connects to the lesser curve of the stomach and the liver. The lesser omentum also contains the portal triad entering the porta hepatis.

Question 7

Describe the location of the small bowel in the abdomen.

Answer 7

It is positioned centrally and is often separated from the anterior abdominal wall by
the greater omentum.

Question 8

The abdominal cavity is lined by

Answer 8

a simple squamous epithelium, the peritoneum (in some books called the serosa).

Question 9

Where the peritoneum covers the inside of the abdominal wall it is called the

Answer 9

parietal peritoneum (remember the pleura)

Question 10

Where the peritoneum covers the viscera (bowel and mesentry) it is called the

Answer 10

visceral peritoneum

Question 11

a space (cavity) between the two layers (visceral and parietal) which is the

Answer 11

peritoneal cavity

Question 12

The distinction between parietal and visceral peritoneum is clinically very important because

Answer 12

they have different nerve supplies and pain from each of them feels different and is felt in different places

Question 13

How do the viscera to slide freely

Answer 13

The cells of the serosa trap a layer of mucous between their microvilli

Question 14

Fluid exudates and pus may collect in recesses within the peritoneal cavity

Answer 14

affecting adjacent structures and tumour cells may spread within the cavity

Question 15

Occasionally the cavity may become distended by fluid -

Answer 15

ascites

Question 16

Some parts of the gastrointestinal tract are suspended by a mesentery and are able to move quite freely while others are more firmly attached and have broader contact with adjacent structures, this is called

Answer 16

(retroperitoneal)

Question 17

The peritoneum is semi-permeable which means that

Answer 17

small molecules can pass freely in and out of the cavity whereas large molecules, such as protein, (normally) cannot

Question 18

In patients with renal failure it may be possible to draw waste products from the blood into the peritoneal cavity and then drain them out of the cavity. This is the basis of

Answer 18

peritoneal dialysis.

Question 19

Mobile parts of the abdominal contains,

Answer 19

such as the ileum or appendix, will move with movement of the body and breathing

Question 20

Diseases which cause inflammation of the surface of these organs will cause pain on moving and breathing

Answer 20

Mobile parts e.g ileum or appendix

. Organs, such as the kidney, which are in a fixed position will not produce pain with movement.