The Gut and the Peritoneal Cavity Flashcards Preview

Anatomy of the abdomen and pelvis > The Gut and the Peritoneal Cavity > Flashcards

Flashcards in The Gut and the Peritoneal Cavity Deck (41)
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1
Q

What type of epithelium is the peritoneum?

A

Simple squamous epithelium - mesothelium

2
Q

What is contained in the peritoneal cavity?

A

Nothing - there is only a small amount of fluid and it is a potential space

3
Q

Which germ layers does the gut tube develop from?

A

Endoderm and splanchnic mesoderm

4
Q

What do the peritoneal folds act as a conduit for?

A

Nerves, blood vessels, lymphatics

5
Q

What is the difference between intraperitoneal and retroperitoneal?

A

Intraperitoneal is totally wrapped in peritoneum whereas retroperitoneal is behind the peritoneum and is not totally wrapped in peritoneum.

6
Q

State three viscera that are secondarily retroperitoneal.

A

Duodenum, pancreas (not tail), colon (ascending and descending only)

7
Q

State some viscera that were retroperitoneal from the start of development

A

Kidneys, great vessels, adrenal glands, oesophagus, rectum

8
Q

What are the three divisions of the gut tube and what defines their borders?

A

Foregut - from the distal 1/3 of the oesophagus to the major duodenal papilla (entrance of the bile duct to the duodenum)

Midgut - 2nd part of the duodenum to 2/3 of the way along the transverse colon

Hindgut - final 1/3 of the transverse colon to the rectum

9
Q

Which mesenteries suspend the different parts of the gut tube?

A

The entire gut tube is suspended by dorsal mesentery

The foregut is ALSO suspended by ventral mesentery

10
Q

What does the ventral mesentery split into?

A

Falciform ligament and the lesser omentum

11
Q

How is the lesser sac (omental bursa) formed?

A

The liver moves right and the stomach and the spleen move left with the dorsal mesentery thus cutting off a space behind the stomach - the lesser sac

12
Q

The liver moves right and the stomach and the spleen move left with the dorsal mesentery thus cutting off a space behind the stomach - the lesser sac

A

Fold of peritoneum between the liver and the lesser curvature of the stomach

13
Q

What is the greater omentum?

A

Lower part of the dorsal foregut mesentery extends down form the greater curvature of the stomach as the greater omentum. It lies like an apron in front of the intestines.

14
Q

What are the dorsal and ventral mesogastria?

A

The mesentery that is joined to the stomach.

15
Q

Why does the lesser omentum have a lower free border and what opening does that form?

A

Because it is formed by the ventral foregut mesentery, which ends at the start of the midgut. The opening to the omental bursa is called the epiploic foramen.

16
Q

What is the transverse colon suspended by?

A

Transverse mesocolon

17
Q

What vessels run within the lesser omentum near its free edge?

A

Hepatic portal vein, hepatic artery proper, bile duct

18
Q

Describe how the abdomen is divided into different compartments.

A

The transverse mesocolon divides the abdomen into supracolic and infracolic compartments. The infracolic compartment is further divided by the mesentery of the small intestine (from the duodeno-jejunal flexure to the ileo-caecal valve) - dividing the infracolic compartment into right and left infracolic compartments.

There are also gutters running along the lateral sides of the ascending and descending colon called the right and left paracolic gutter.

19
Q

Describe the how the direction of movement of peritoneal fluid differs from that of inflammatory exudate.

A

Peritoneal fluid moves towards the diaphragm

Inflammatory exudate moves towards the pelvis

20
Q

State the layers of the gut tube.

A

Mucosa, submucosa, muscularis, serosa/adventitia

21
Q

Which layers have nerve plexuses and what are they called?

A

Submucosa - Meissner’s plexus

Muscularis (myenteric) - Auerbach’s plexus

22
Q

At which vertebral position does the oesophagus penetrate the diaphragm and through which crus?

A

T10 - through the right crus

23
Q

What are the different parts of the stomach?

A

Cardia, fundus, body, pyloric antrum and pyloric canal

24
Q

What are the four parts of the duodenum?

A

Superior, descending, inferior, ascending

Superior is where the duodenal cap is located - this is a common location for duodenal ulcers

25
Q

What is the major duodenal papilla and where is it found?

A

The major duodenal papilla is the opening of the bile duct to the duodenum - it is in the descending part of the duodenum

26
Q

Describe three ways in which the jejunum and ileum differ.

A

Jejunum has a greater diameter, longer vasa recta and less prominent arterial arcades

27
Q

Describe three ways in which the colon differs from the small intestines.

A

Colon has taenia coli (ribbons of longitudinal muscle)

Colon has fatty tags - appendices epiploicae

Colon has a segmental/pocketed arrangement

28
Q

What are the three main arteries supplying the gut and what do each of them supply?

A

Coeliac Trunk - foregut (and pancreas, liver, spleen)

Superior Mesenteric Artery - midgut

Inferior Mesenteric Artery - hindgut

29
Q

What does the coeliac trunk divide into?

A

Common Hepatic Artery

Left Gastric Artery

Splenic Artery

30
Q

What are the branches of the superior mesenteric artery?

A

Jejunal Arteries

Ileal Arteries

Iliocolic Artery

Right Colic Artery

Middle Colic Artery

31
Q

What are the branches of the inferior mesenteric artery?

A

Left Colic Artery

Sigmoid Arteries

Superior Rectal Artery

32
Q

Describe the venous drainage of the gut.

A

The venous drainage does NOT follow the arterial supply. All the venous blood from the gut drains through the liver. The inferior mesenteric vein joins the splenic vein and the splenic vein then joins the superior mesenteric vein to form the hepatic portal vein. The superior mesenteric vein joins the splenic vein behind the first part of the duodenum.

33
Q

Where do you find portal-systemic anastamosis?

A

Oesophagus, rectum, umbilicus

Oesophagus: between oesophageal vein and left gastric vein

Umbilicus: between umbilical vein and epigastric veins

Rectum: between superior rectal vein and inferior rectal vein

NOTE: there is a fourth anastomosis between the colic veins and posterior abdominal wall veins

34
Q

What is the clinical significance of the portal-systemic anastamoses?

A

If there is liver damage or a blockage then you get portal hypertension leading to dilation of the porto-systemic anastomoses, which could possibly lead to oesophageal or rectal haemorrhage.

35
Q

Describe the lymphatic drainage of the gut.

A

The lymphatics follow the arteries. There are coeliac lymph nodes, superior mesenteric lymph nodes and inferior mesenteric lymph nodes. They all drain into the cysterna chyli and then through the thoracic duct.

36
Q

Which vertebral level is the cysterna chyli positioned at?

A

(in front of the vertebral body of) L1 and L2

37
Q

What are the main parasympathetic sensory nerves of the gut?

A

Vagus Nerve

Pelvic Splanchnic Nerves (S2-S4)

38
Q

What are the main sympathetic sensory nerves of the gut?

A

Thoracic Splanchnic Nerves (T5-T12)

Lumbar Splanchnic Nerves (L1+L2)

39
Q

What are the roles of the parasympathetic sensory and sympathetic sensory nerves of the gut?

A

Parasympathetic Sensory - involved in regulate reflex gut function

Sympathetic Sensory - mediate pain

40
Q

What are the three divisions of the thoracic splanchnic nerves?

A

Greater Thoracic Splanchnic - T5-T9

Lesser - T10-T11

Least - T12

41
Q

Why are the sensory fibres the most important clinically?

A

They are involved in mediating pain sensation.