15

Question 1

anatomy of the liver

Answer 1

• diaphramatic (anterior/superior) and visceral (posterior/inferior) surfaces
• lies in the right hypochondriac and epigastric regions
• extends to left hypochondriac and right lumbar regions
• largest visceral organ
• wrapped in tough fibrous capsule

Question 2

lobes of the liver

Answer 2

• right lobe (largest)
• left tobe
• caudate lobe (on posterior surface of right lobe to the left of the fossa/IVC)
• quadrate lobe inferior to caudate lobe, between left lobe and gallbladder

Question 3

peritoneal covering of liver

Answer 3

coevered by visceral peritoneum except at the bare area (between the 2 coronary ligaments)

falciform ligament - attaches liver to the anterior abdominal wall

• divides anterior surface into right and left lobes
• remnant of umbillical vein

round ligament

• fibrous band in free margin of falciform ligament
• represents obliterated umbillical vein

livers connected to lesser omentum

Question 4

porta hepatis

Answer 4

“doorway to liver”

• where bvs and other structures converge on liver
• vessels reach liver by travelling within CT of lesser omentum

Question 5

hepatic triad

Answer 5

branches of hepatic artery proper, hepatic veins and bile ducts

Question 6

hepatic artery proper

Answer 6

branch of celiac artery

-carries oxygenated blood to the liver tissues

Question 7

hepatic portal vein (forms from?)

Answer 7

• carries nutrient rich venous blood from the digestive tract (esophagus, stomach and intestines)
• forms from convergence of splenic and superior mesenteric veins

Question 8

bile duct

Answer 8

carries bile from the liver

Question 9

blood supply to liver

Answer 9

from hepatic artery (1/3 arterial blood) and hepatic portal vein (2/3 venous blood)

• blood enters via liver sinusoids (frenstrated capillaries) > central veins > hepatic veins > IVC
• largest blood resevoir in body (25% of CO)

Question 10

liver lobules

Answer 10

• basic functional units of the liver
• 1 mm in diameter
• seperated by interlobular septa
• formed from hepatocytes arranged in plates radiating outwards from a central vein
• 6 hepatic triads at the periphery of each lobule
• between the plates of hepatocytes are sinusoids

Question 11

sinusoids

Answer 11

• blood from the portal vein (with products of digestion) enters sinusoids
• components leave to enter the perisinusoidal space - in contact with the hepatocytes which absorb products via microvili
• remaining blood in sinusoids enters central veins which connect to hepatic veins which connect to IVC
• have Kupffer cells

Question 12

hepatocytes

Answer 12

main cells of liver

• adjust circulating levels of nutrients by selective absorbtion/secretion
• absorb solutes from plasma
• secrete materials (e.g. plasma proteins)
• secrete bile into canaliculi which connect to the bile duct system

Question 13

Kupffer cells

Answer 13

• liver macrophages
• remove bacteria and foreign particles from blood
• work w spleen to remove old rbc’s

Question 14

intrahepatic bile duct system

Answer 14

• hepatocytes secrete bile into bile canaliculi (narrow channels between opposing cell membranes of adjacent hepatocytes that extend out & away from central vein)
• bile canaliculi open in fine bile ductules that carry bile to a duct in the nearest portal triad

Question 15

extrahepatic bile duct system

Answer 15

bile drains into right and left hepatic ducts

• unite to form common hepatic duct
• joins cystic duct from gallbladder to form the common bile duct
• joins pancreatic duct at hepatopancreatic ampulla and releases into duodenum

Question 16

common bile duct

Answer 16

delivers bile

-enters the duodenum

Question 17

cystic duct

Answer 17

-has mucosal spiral fold - keeps lumen open allowing bile to pass either way (to common bile or cyctic duct)

Question 18

pancreatic duct

Answer 18

delivers digestive enzymes and buffers

Question 19

hepatopancreatic ampulla (of vater)

Answer 19

• both the pancreatic and common bile ducts meet here
• opens at the duodenal papilla halfway along the length of the doudenum
• encircled by the hepatopancreatic sphincter (of oddi)

Question 20

gallbladder anatomy

Answer 20

• pear shaped muscular sac
• located at the fossa on the posterior surface of the right hepatic lobe
• has three regions: fundus, body and neck

Question 21

blood supply to gallbladder

Answer 21

cystic artery

Question 22

gallbladder function

Answer 22

• stores and concentrates bile (full = 40 -70 ml bile)

- releases bile into duodenum under control of cholecystokinin hormone

Question 23

direction of bile flow in absence of chloecystokinin

Answer 23

• sphincter of oddi remains closed
• bile exiting liver in common hepatic duct can’t flow through common bile duct to duodenum
• so it enters the cystic duct to be stored in the gallbladder

Question 24

direction of bile flow when cholecystokinin is released

Answer 24

• sphincter of oddi opens
• gallgladder wall contracts
• bile flows into cystic duct to common bile duct to duodenum

Question 25

gallbladder histology

Answer 25

mucosa - simple columnar epithelium w apical microvili - lamina propria - no muscularis mucosae little or no submucosa muscularis muscosa not arranged in distinct layers -perimuscular fibrous tissue layer adventitia

Question 26

anatomy of pancreas

Answer 26

- retropartioneal - lies posterior to stomach - extends from duodenum towards spleen - bound to posterior wall of abdominal cavity - wrapped in thin CT capsule - mixed exocrine and endocrine glands

Question 27

regions of pancreas

Answer 27

- head - broad and in concavity of duodenum - body - long and slender - extends towards spleen - tail - short and round tip of pancreas - reaches spleen

Question 28

histology of pancreas

Answer 28

- 99% exocrine tissue, 1% endocrine tissue | - divided into lobules, separated by CT septa

Question 29

exocrine tissue of pancreas

Answer 29

- compound tubuloalveolar glands have acinar cells that also secrete pancreatic juice - have pancreatic acini (blind pockets) - -lined with simple cuboidal epithelium - -secrete pancreatic juice - -empty into small ducts that eventaully open into main pancreatic duct

Question 30

endocrine tissue

Answer 30

-pancreatic islets (of langerhans) -scattered among acini -have endocrine cells: alpha cells, beta cells, delta cells, PP cells

Question 31

alpha cells

Answer 31

produce/secrete glucagon

Question 32

beta cells

Answer 32

produce/secrete insulin

Question 33

delta cells

Answer 33

produce/secrete somatostatin (GHIH)

Question 34

PP cells

Answer 34

produce/secrete pancreatic polypeptide

Question 35

arterial blood supply to pancreas

Answer 35

- branches of celiac and superior mesenteric arteries supply head - and splenic artery (runs along superior boarder of pancreas) - supplies body and tail

Question 36

venous drainage of pancreas

Answer 36

corresponding celiac, superior mesenteric and splenic veins drain into the hepatic portal vein