Liver and Friends Anatomy

Question 1

What is the liver an embryological derivative of?

Answer 1

The liver is an embryological derivative of the foregut and develops in the ventral mesentery. In the adult this ventral mesentery becomes the lesser omentum and the various ‘ligaments’ which hold the liver in close relation to the right dome of the diaphragm.

Question 2

What is the bare area in the liver?

Answer 2

Most of the surface of the liver is covered by peritoneum but one area of the liver has no peritoneal covering and lies in direct contact with the diaphragm, this is the bare area.

Question 3

How does the liver receive the venous blood from the bowel?

Answer 3

The liver receives all of the venous blood from the bowel via the hepatic portal vein

Question 4

What can cause the liver to become enlarged?

Answer 4

The liver becomes enlarged if blood flow though it is impeded by such conditions as congestive heart failure, cirrhosis, tumours, or viral infections (hepatitis).

Question 5

How can gall stones lead to jaundice?

Answer 5

The gall bladder is closely applied to the surface of the liver, the ducts carrying bile from the liver and/or gall bladder can become blocked by stones (gall stones) leading to considerable discomfort and may result in jaundice.

Question 6

What is the duct for the gall bladder and the duct for the liver?

Answer 6

The duct for the gall bladder is the cystic duct and the duct for the liver the hepatic ducts.

Question 7

What are the two tributaries of the hepatic duct?

Answer 7

the right and left hepatic ducts

Question 8

What is the position of the portal triad?

Answer 8

The position of the divided portal triad is immediately in front of epiploic foramen, the entrance to the lesser sac

Question 9

What fissures are seen on the inferior surface of the liver? What are the lobes of the liver? and what impressions are made in the liver?

Answer 9

define the fissures for the ligamentum teres and ligamentum venosum

the right, left, caudate and quadrate lobes

and the impressions made by the stomach, right kidney, hepatic flexure of the colon and the gall bladder.

Question 10

What ligaments are present on the liver?

Answer 10

falciform ligament, the coronary ligaments, and triangular ligaments

Question 11

What is the biliary tree?

Answer 11

The biliary system includes the gallbladder and bile ducts inside and outside the liver. Also called biliary tract.

Question 12

What is the name of the spiral fold of mucosa running down the cystic duct?

Answer 12

the spiral valve

Question 13

What is the venous drainage of the liver?

Answer 13

The hepatic veins, they drain into the Inferior Vena Cava

Question 14

What is the surface marking of the superior aspect of the liver?

Answer 14

Notice that the liver is almost completely above the costal margin and bulges up to the fifth intercostal space on the anterior chest wall.

Question 15

What is biliary colic?

Answer 15

The gall bladder contracts in response to fatty foods entering the duodenum and when it squeezes against gall stones it can be painful; biliary colic.

Question 16

What happens in liver failure to toxic short chain proteins?

Answer 16

The liver (normally) receives all venous blood from the bowel. Ingested proteins which are digested and absorbed by the bowel often consist of chains of three or more amino acids. The short chain protein are toxic to the brain as they can act as neurotransmitters. The liver removes all these proteins and reconfigures them into ‘safe’ molecules. In liver disease this process may fail or blood may bypass the liver through a porto-systemic shunt. The patient will develop neurological disease as a result, hepatic encephalopathy (opathy – disease, .encephalo - of the inside of the head, hepatic - due to the liver).

Question 17

Why can gall bladder diseases cause pain the right shoulder?

Answer 17

The fundus of the gall bladder lies against the under surface of the diaphragm. Disease of the gall bladder may cause rubbing on the diaphragm. The pain produced will be carried by the phrenic nerve into the 3, 4 and 5 cervical nerve roots. The patient will feel the pain in the skin supplied by the 3, 4 and 5 cervical nerve roots. This is over the right shoulder.

Question 18

Which artery is the cystic artery a branch of?

Answer 18

It is usually the right hepatic artery but it can be the left hepatic or the hepatic artery

Question 19

Which structures can be found in the porta hepatis?

Answer 19

Macroscopically; portal vein, right and left hepatic artery, right and left hepatic duct Microscopically, lymphatics branches of the vagus and greater splanchnic nerves

Question 20

What structure degenerates to form the ligamentum venosum?

Answer 20

The ductus arteriosus; an embryological bypass for the liver which exists before the liver has fully formed.

Question 21

Where is the bare area of the liver?

Answer 21

Under the central tendon of the right side of the diaphragm

Question 22

What is the surface marking of the fundus of the gall bladder?

Answer 22

The tip of the ninth costal cartilage. Where the midclavicular line crosses the costal margin. The most lateral attachment of the rectus abdominis onto the costal margin. (These are all the same place and just different ways of saying the same thing).

Question 23

Which nerves may relay pain from diseases of the gall bladder and for each nerve where will the patient feel the pain?

Answer 23

The lesser splanchnic nerve, pain in the midgut, if it rubs on the parietal peritoneum pain will be carried by the intercostal nerves and will be felt at the position of the gall bladder, it can also rub on the inferior aspect of the diaphragm and stimulate phrenic nerve C3,4, and 5 and give pain in the right shoulder

Question 24

What is the porta hepatis?

Answer 24

• ‘Entrance to the liver’
• Transmits 3 important structures in and out of the liver:
1. Hepatic Artery Proper
2. Hepatic Portal Vein
3. Common Bile Duct
• (also nerves and lymphatics)

Question 25

What is the blood supply for the liver and gall bladder?

Answer 25

As they are foregut structures, arterial supply comes from the coeliac trunk via the Hepatic Artery Proper, which splits into Right & Left Hepatic Arteries. • The branch to the gallbladder is called the Cystic Artery and normally branches from the Right Hepatic Artery.

Question 26

What is bile?

Answer 26

Bile is produced in the liver and stored in the gallbladder. • After production, bile is transmitted down the Hepatic Ducts (R & L) which merge to become the Common Hepatic Duct. This then gives off the Cystic Duct, a branch to deposit bile in the gallbladder for storage. • When necessary (usually after eating a fatty meal), bile is released from the gallbladder, again via the cystic duct, into the Common Bile Duct which joins the duodenum.

Question 27

What are gallstones?

Answer 27

Made from bile components, namely cholesterol, bile salts and bilirubin. • Often asymptomatic, they just rattle around in the gallbladder not causing any trouble. • If they obstruct the outflow of the gallbladder (the cystic duct), or progress through the cystic duct to obstruct the common bile duct, they can cause cramp-like pulsatile pain as the gallbladder contracts against an obstruction. This is called ‘Biliary Colic’ pain. • If they obstruct the outflow for long enough, the gallbladder can become infected, this is called ‘Cholecystitis’. • Can also lead to other complications like pancreatitis and jaundice

Question 28

What is Cholecystitis Pain?

Answer 28

If the gallbladder becomes inflamed, the pain may be felt in one of three places via three pathways. 1. Via the Greater Splanchnic Nerve: as the gallbladder is a foregut structure, its pain is felt through the greater splanchnic nerve (T5- T9) which causes a dull, vague pain in the epigastric region. 2. Via the Parietal Peritoneum: if the gallbladder comes into contact with the parietal peritoneum (which is innervated by the same nerves that supply the skin over the abdomen), it is felt accurately over the area of contact as sharp, well-localised pain. 3. Via the Phrenic Nerve: if the gallbladder comes into contact with the diaphragmatic layer of the parietal peritoneum (which is innervated by the Phrenic Nerve C3-C5), it is felt in the right shoulder