Iusm Histology: Glands Of The Digestive Tract

Front 1

Hep C symptoms

Back 1

fever, headache, muscle aches, fatigue, loss of appetite, nausea, vomiting, diarrhea, hepatomegaly and jaundice

Front 2

Treatment for HepC

Back 2

24 or 48 weeks fo pegylated alpha IFN and ribavirin

Front 3

Exocrine functions of the liver

Back 3

excrete 600 ml of bile per day

Front 4

bile is composed of

Back 4

organic ingredients: bile acids, phospholipids, cholesterol, bilirubin, bile pigment, inorganic salts

Front 5

Bile function:

Back 5

excretion of cholesterol, phospholipids, bilirubin and electrolytes. Helps with fat absorption, IgA transport and excretion of drug metabolic sideproducts and heavy metals

Front 6

Endocrine function of the liver

Back 6

Releases albumin, lipoprotein, globulins and liver glycogen into the blood

Front 7

75% of the liver's blood comes from:

Back 7

Hepatic portal vein (deoxygenated blood from small intestine, pancreas and spleen)

Front 8

25% of the liver's blood comes from:

Back 8

oxygenated blood from the hepatic artery

Front 9

blood from the portal vein and hepatic artery mix where?

where does the resulting mixed blood converge?

Back 9

sinusoides of the liver lobules, which converge at the central venule of the liver lobule. This in turn converges to form the sublobular vein and ultimately the IVC

Front 10

Main difference between bile flow and blood flow

Back 10

direction (opposite)

Front 11

Bile leaves the liver lobule via

Back 11

intrahepatic bile duct followed by the extrahepatic ducts (the right/left hepatic ducts and the main hepatic duct). The bile is then stored in the gallbladder before being exceted into the common bile duct and into the duodenum.

Front 12

Bile enters the small intestine through what openning?

Back 12

The hepatopancreatic ampulla of Vater

(this ampulla encompasses the pancreatic duct as well as the common bile duct)

Front 13

Define hepatic lobule

Back 13

functional and structural unit of the liver

Front 14

hepatic lobule consists of :

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anastomosing plates of hepatocytes lining blood sinusoidal spaces

Front 15

Bile initially drains from tissue into:

Back 15

bile canaliculi (again, flowing the opposite direction of blood)

Front 16

Define the Portal Triad

Back 16

includes the hepatic artery, the portal vein, and the bile duct
*lymphatic capillaries/vessels are also part of the portal triad.*

Front 17

the portal triad is located where?

Back 17

at the vertices of the hexagonal-shaped liver lobule in what is known as 'the portal space'

Front 18

characterize the liver sinusoids

Back 18

sinusoidal capillaries are fenestrated with large 0.5um pores

basement membrane is discontinuous, endothelium is discontinuous

Front 19

what is a kupferr cell?

Back 19

a macrophage roaming the sinusoids of the liver lobule

Front 20

what does a kupferr cell do?

Back 20

phagocytoses RBCs and bacteria, degrades hemoglobin to form bilirubin, secretes IL1 and TNF

Front 21

Characterize blood flow in the classic liver lobule

Back 21

periphery to center

Front 22

Why is the direction of blood flow important?

Back 22

The perilobular region has higher levels of O2, hormones, metabolites, toxic substances than the centrolobular region does. this changes gene expression patterns (ie: P450

Front 23

What is the space of Disse?

Back 23

This is located between the sinusoid and the basolateral domain of hepatocytes. Enables exchange between blood and hepatocyte. absorptive function of hepatocyte is increased by microvilli extending into this space.

Front 24

What cells are found in the space of Disse?

Back 24

Hepatic stellate cells of Ito
(store and metabolise vitamin A, as well as synthesize extra-cellular matrix proteins)

Also contains unmyelinated nerve axons

Front 25

What diseases are correlated to the cells of Ito?

Back 25

Fibrosis of the liver, due to increased production of EC matrix proteins.

Front 26

Please describe the flow of bile including every tubule it flows through

Back 26

Bile canaliculi>>intralobular ductules (canals of Hering)>>bile ductules/interlobular>>intrahepatic bile ducts>>left and right hepatic ducts (merge)>>common hepatic duct>> (exits liver) cystic duct>>gall bladder>>common bile duct>>joints with pancreatic duct>>Ampulla of Vater>>duodenum

Front 27

What is the classic hepatic lobule?

Back 27

central venule with portal triads at the angles of the hexagonal

Front 28

What is the portal lobule?

Back 28

Contains portions of hepatic lobules, bounded by the central veins of 3 adjacent lobules. Defined by lobules whose bile canaliculi drain into the same bile duct (found in the center of the portal lobule at the intersection of the 3 hepatic lobules)

Front 29

Define liver acinus

Back 29

defined by hepatic tissue recieving blood from a hepatic artery conducting blood to opposite central veins.
Split into three zones (I, II and III)

Front 30

Characterize zone I of a liver acinus

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hepatocytes synthesize glycogen and plasma proteins. O2 is high

Front 31

Characterize zone II of a liver acinus

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intermediate region, O2 is neither high nor low.

Front 32

Characterize zone III of a liver acinus

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O2 concentration is low. Role in detoxification. hepatocytes are susceptible to damage by hypoxia

Front 33

What papilli does bile get secreted through into the duodenum?

Back 33

the major duodenal papilla

Front 34

how is the ampulla of Vater regulated?

Back 34

smooth muscle sphincters

Front 35

What does cholecystokinin do?

Back 35

contracts the gallbladder and relaxes the major duodenal papilli sphincters (end result: bile secreted into intestinal lumen in response to dietary fat)

Front 36

cholecystokinin is released by what cells?

Back 36

small intestine enteroendocrine cells

Front 37

gall bladder is lined by what type of tissue?

Back 37

simple columnar epithelium

Front 38

describe the microvilli of the gallbladder and their function

Back 38

epithelial cells have lateral-basal microvilli that extend into intercellular clefts.

This mediates high sodium transport and the removal of water from the bile (bile concentration)

Front 39

Who is at high risk for gallstones?

Back 39

women
>60 years old
native americnas
mexican americans
overweight
people who gain/lose weight quickly
pregnant women, women on birth control, women with hormone replacement therapy

Front 40

What are the symptoms of gallstones?

Back 40

steady and increasing pain in upper abdomen lasting 30 mins -->multiple hours.

pain between shoulder blades, pain under the right shoulder, nausea, vomitting

Front 41

treatment for gallstones (main categories only)

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surgury
oral dissolution
contact dissolution

Front 42

name of surgury to remove gallbladder

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laparoscopic cholecystectomy

Front 43

describe oral dissolution therapy

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drugs made of bile acid: ursodiol (Actigall) and chenodiol (Chenix) work best. May take months-years

Front 44

Describe contact dissolution therapy

Back 44

experimental technique. injecting a drug (methyl tertbutyl ether) directly into the gallbladder. Takes only 1-3 days but is a flammable anesthetic that can be toxic.