Peritoneal cavity 2

Question 1

where does the oesophagus perices the diaphragm?

Answer 1

at T10.

the diaphragm contriutes to the formation of the lower oesophageal sphincter.

Question 2

what is the lower oesophageal sphincter?

Answer 2

sphincter which helps prevent gastro-oesophageal reflux

there are NO specific sphincter muscles involved.

HOWEVER the diaphragm helps form that sphincter.

L@D (look at diagram)

Question 3

where is the gastro-oesophageal junction?

Answer 3

T11

Question 4

what kind of phenomenae forms that lower oesophageal sphincter?

Answer 4

The oesophagus enters the stomach at anacute angle.
The walls of the intra-abdominal section of the oesophagus arecompressedwhen there is a positive intra-abdominal pressure.

Thefolds of mucosapresent aid in occluding the lumen at the gastro-oesophageal junction.
The right crus of the diaphragm has a“pinch-cock”effect.

Question 5

name the parts of the stomach. sup to inf

what is the sphincter?

What kind of peritoneal organ is the stomach?

Answer 5

fundus, body, pyloric antrum and pyloric canal.

End of the pyloric canal, there is a muscular sphincter which prevents food from entering the duodenum -> PYLORIC SPHINCTER

Stomach is INTRAPERITONEAL

Question 6

Describe the arterial supply to the foregut

Answer 6

From the abdomenal aorta. Left Gastric and Splenic a. (TO THE LEFT OF AA - from the COELIAC TRUNK) and Common hepatic artery (RIGHT of the AA)

SPLENIC goes to the left gastro-omental and pancreatic artery.

COMMON Heptaic artery goes to form the Gastroduodenal (inferiorly) and the PROPER HEPATIC (ventrally right). These will further split.

GASTRODUO -> Rt gastroepiploic a (going left) AND Superior Pancreato-duodenal a. (going down)

PROPER HEPATIC -> Right Gastric a (up) AND Left and Right Heptic a AND cystic a off the rt hepatic.

Question 7

what are the branches of the gastroduodenal artery?

Answer 7

right-gastroepipolic artery and the superior pancreatico-duodenal artery

Question 8

what are the branches of the proper hepatic artery?

Answer 8

right gastric
hepatic
cystic (off the right)

Question 9

what s the structure of the dueodeum?

How many parts does it have?

Whichparts are covered by which peritoneum?

Answer 9

C-shaped

Four parts
Superior
Descending
Inferior
Ascending

beginning of the first and end of fourth are covered by the intraperitoneal mesentry

Otherise they are RETROPERITONEAL

The first part is common place for ulcers
second part is th location for major duodenal papilla

Question 10

what are the blood supplies of the duodenum?

Answer 10

first half (foregut) - coeliac trunk
second - superior mesenteric artery

Question 11

describe the proximal sizes of the jej and ileum.

how are they distingusihed?

peritonium?

where does the SI end?

Answer 11

The jejunum makes up the proximal 2/5
The ileum makes up the distal 3/5

No clear junction, but macroscopically different.

Intraperitoneal

Ends with ileocaecal valve

Question 12

what is a haustrum?

Answer 12

small pouches caused by sacculation which gives the colon its segmented shape.

Question 13

what are omentum apendices?

Answer 13

Omental appendices (appendices epiplociae) are small pouches of the peritoneum filled with fat and situated along the colon, but are absent in the rectum.

Question 14

what is the taeniae coli?

Answer 14

the longitudinal muscle on the large int

Question 15

describe the blood supply to the three parts of the gut?

Answer 15

FG - coeliac trunk - supplies the liver, panc, stomach and spleen (spleen not part of ali system) and first part od duodenum.

MG: supeior mesent art. Small intestines and 2/3 of transverse colon

HG: inferior mesent artry - 1/3 of transverse
colon and rectum

Question 16

what are the branches of the superior mesenteric artery, goin clockwise

Answer 16

5 branches - Jejunal, ileal, ileocolic, right colic and middle colic

Question 17

how do you compare // jej and ileium?

Answer 17

In comparison to the ileum (B) the jejunum (A) has:
A wider diameter
Longer vasa recta
Less prominent arterial arcades (below the vasa recta)

Question 18

what are the branches of the inferior mes art?

Answer 18

Left colic artery
Superior rectal artery
Sigmoid arteries

Question 19

describe the drainage of the gut

where does the portal vein form?

where does it run to?

Answer 19

The entire gut drains into the portal system

Posterior to the first part of the duodenum the portal vein forms

It then runs to the liver through the hepatic portal vein.

Drainage:
Foregut: Portal vein and splenic vein
Midgut: Superior mesenteric vein
Hindgut: Inferior mesenteric vein

Question 20

what is the portosystemic anastomosis?

Answer 20

A portacaval anastomosis is a specific type of anastomosis that occurs between the veins of the portal circulation and those of the systemic circulation.

How are they diff> Portal veins are those that do not go to the heart first, they go liver first.

Question 21

what does the lymph drainage of the bowels follow?

Answer 21

they follow the arterial supply.

Foregut: Coeliac nodes
Midgut: Superior mesenteric nodes
Hindgut: Inferior mesenteric nodes

Question 22

where does the lymph drain in the abdomen?

Answer 22

all lymph drains into the CISTERNA CHYLI - An elongated lymphatic sac located in front of the L1 & L2 bodies

The thoracic duct starts from the cisterna chyli. REMEBER the duct is the tube going up.

Question 23

Describe the MOTOR innervation to the abdominal viscera

Answer 23

Parasympathetic and symp NS.

6 key nerves innervate the abd
CNX - VAGUS (PARA)

THORACIC SPLANCHNIC NERVE (T5-T12) (SYP)

• -> Greater splanchnic nerves (T5-T9)
• -> Lesser splanchnic nerves (T10-T11)
• -> Least splanchnic nerves (T12)

LUNBAR SPLANCHNIC N. (L1-L2) (SYMP)

PELVIC SPLANCHNIC N. (PARA) (S2-4)

REMEMBER: with SYMPATHETIC NS there are three ways in which the neurons from the CNS synapse. 1) Via paravertebral trunk (sympathetic trunk) (2) Via the prevertebral ganglion (3) Direct - like Adrenal meduall.

The ABOVE neruone are splanchnic and are the pre-vertebral ganglionic ones.

Question 24

Where are the ganglia to the splanchnic nerves?

Answer 24

Prevertebral (lie // the paracertebral and the viscera)

Coeliac plexus
Superior mesenteric plexus
Inferior mesenteric plexus

Question 25

what is the sensory innervation of the abd like?

Answer 25

sensory nerves run alongside the autonomic

Nerves adjacent to the sympathetic nervous system mediate pain

Nerves adjacent to the parasympathetic nervous system are involved in reflex regulation and gut function

Question 26

what is referred pain?

Answer 26

Visceral pain

Poorly localised

Referred to dermatomes that are supplied by the same sensory ganglia and spinal cord segments.

Referred according to embryological origin – foregut to epigastric, midgut to umbilicus, hindgut to suprapubic

Retroperitoneal -> back pain

Often accompanied by autonomic
disturbance e.g. nausea, diarrhoea

Question 27

Name the PORTOSYSTEMIC ANASTOMOSIS

Answer 27

Oesophageal and left gastric veins:-
—-> Site of oesophageal varices*

Superior and inferior rectal veins:-
—>Site of haemorrhoids*

Paraumbilical and epigastric veins:-
—->Site of caput medusa*

Colic and abdominal wall veins