[Physiology] Liver Structure and Function Flashcards
what is the largest organ in the body
liver (1.4kg)
where is the liver located
upper right quadrant of abdomen
where is the liver located in relation to the diaphragm
tucked against inferior surface of diaphragm
what are the two major lobes of the liver
right and left
what are the two minor lobes of the liver
caudate and quadrate
what covers the liver
connective tissue capsule and visceral peritoneum except for bare area
what is the bare area of the liver
small area on diaphragmatic surface surrounded by coronary ligament
what follows the septa throughout the liver
connective tissue capsule
what does the septa divide the liver into
hexagonal lobules
what is the portal triad
hepatic portal vein, hepatic artery, hepatic duct
where is the portal triad located
at each corner of hexagonal lobule
what else is also located at each corner of hexagonal lobule
nerves and lymph nodes
what is at the centre of each liver lobule
hepatic veins
where do hepatic veins drain to
IVC
where do hepatic cords radiate out from
central veins
what are hepatic cords composed of
hepatocytes
what are hepatocytes
functional cells of the liver
where do bile canaliculus lie
between cells within each cord
what are the spaces between hepatic cords
hepatic sinusoids (blood channels)
what is the alimentary role of the liver
production & secretion of bile
what are the components of bile synthesised in the liver
Bile acids
Lecithin
Cholesterol
what are the six components of bile
Bile acids
Lecithin
Cholesterol
Bile Pigments
Toxic Metals
Bicarbonate
what are five of the compoents of bile secreted by
hepatocytes
what component is secreted by duct cells
HCO3
bile pigments
breakdown products of haemoglobin from old/damaged erythrocytes
bilirubin
(predominant bile pigment) - extracted from blood by hepatocytes and secreted into bile
what is bilirubin also known as
yellow bile
what is bilirubin modified by
bacterial enzymes ⇒ brown pigments
brown faeces
Reabsorbed bilirubin excreted in urine
yellow urine
bile acids
Synthesised in liver from cholesterol (0.5g/day)
what occur to bile acids prior to secretion
bile acids conjugated with glycine or taurine ⇒ Bile Salts (↑ solubility)
what happens to secreted bile salts
recycled via enterohepatic circulation
what is the gall bladder
Saclike structure (8 cm long x 4 cm wide) on inferior surface of liver
what are the three layers in the gall bladder wall
mucosa
muscularis
serosa
mucosa
(folded ⇒ rugae ⇒ expansion)
muscalaris
(smooth muscle) ⇒ contraction
serosa
(connective tissue)
sphincter of oddi
controls release of bile and pancreatic juice into duodenum
what happens when sphincter of oddi is contracted
bile forced back into gallbladder
what does gallbladder do to bile
concentrates bile 5-20 times (absorbs Na+ & H2O)
what does fat in the duodenum cause
release of CCK
what occurs when CCK is released
(A) Sphincter of Oddi relaxes
(B) Gallbladder contracts
what is produced when acid is in duodenum
secretin
what does secretin cause
↓ Gastric acid secretion
↓ Gastric emptying
↑ Duodenal HCO3 secretion
↑ Pancreatic HCO3 secretion
↑ Bile duct HCO3 secretion
what does secretin result in
acid neutralisation
what does fat/amino acids in duodenum cause to be released
CCK
what does CCK result in
↓ Gastric emptying
↑ Pancreatic enzyme secretion
Gallbladder contraction
Relaxation of Sphincter of Oddi
what is the end goal of CCK
digestion
