Liver, Gallbladder & Pancreas

What is the liver and where is it located

The liver is the largest gland in the body and it is located in the Upper Right Quadrant inferior to the diaphragm

What is the main digestive function of the liver

to secrete bile

What are the 4 lobes of the liver

Right, left, caudate and quadrate

Right lobe of liver

Liver left lobe

Liver caudate lobe

Liver quadrate lobe

Falciform ligament of liver

Bile

Yellow green fluid secreted by the liver that facilitates fat and cholesterol absorption

What does bile contain

Bile acid/salt and pigments

Bile acid/ salt

a component of bile - cholesterol derivative that helps with fat emulsification (basically breaking down fat into smaller pieces so there is more surface area for digestive enzymes to work with)

Bile pigment

the primary bile pigment is bilirubin which is recycled from hemoglobin

Liver

Gallbladder

What is the gallbladder and where is it located

thin walled pear shaped sac that is located posterior of the liver (URQ)

What is the 3 main function of galllbladder

store bile, concentrate the bile, and release bile

Pathway that the bile leaves the gallbladder

It leaves via the cystic duct and enters the common bile duct

Cholelithiasis

presence of gallstones (hardened deposits of bile) which can block the ducts

Where is the pancreas

it is retroperitoneal and it is located posterior to the greater curvature of the stomach
and the head is encircled by the duodenum

retroperitoneal vs intrapertioneal

retroperitoneal means behind the peritoneal
intraperitoneal means covered by the peritoneal (surrounded) → touching the visceral part

4 parts of the pancreas

head, neck, body, and tail

Pancreatic duct

What type of gland is the pancreas

endocrine and exocrine gland

Endocrine gland (what is it) and what does it release for the pancreas

release hormones into the blood → insulin and glucagon

Exocrine gland - what is it and what does the exocrine pancreas secrete

secretions into a duct to somewhere else
pancrease secretes pancreatic juice

Pancreatic juice

exocrine secretion by pancreas that contains digestive enzymes and bicarbonate ions

Pancreatic juice is a _____ solution with a pH of ___
and is a mixture of what

alkaline pH 8 → to neutralize acidic chyme

water, electrolytes (HCO3-) and enzymes/zymogens (inactive digestive enzymes)

Pancreatic juice digestive enzymes / zymogens

protease → protein

amylase → starch

lipase → fat

nuclease → nucleic acid

Zymogens

inactive digestive enzymes precursor

What are the three regulations of secretion of bile and pancreatic juic

ACh (acetylecholine), cck(cholecytokinin) , secretin

Ach (acetylcholine) -from what and during when
does what

from vagus nerve and enteric nerve during cephalic and gastric phase

initiates enzyme production → weak gallbladder contraction → release some bile from gallbladder to duodenum

Cck - cholecystokinin - what releases it and when

released by mucosa of duodenum as a reaction of chyme enters the small intestines (arrival of FAT!!!)

Function of cck cholecystokinin

stimulates gallbladder contractions (more than ACh) → causes bile to be released into the duodenum → emulsifying chyme (specifically the fat) (making it into smaller bits)
it also causes secretio of pancreatic juice which has enzymes → break down the chyme (fat)

Secretin - what releases it and when

also released by duodenum as a reaction to acidic chyme coming from the stomach
ACID!!!

Secretin function

stimulates liver and pancrease to secrete more sodium bicarbonate to increase the pH (counteracts the acidic chyme coming from stomach) so that digestive enyymes from the pancreas and intestine can work