Organ Systems II MT4 SSL Liver I

Question 1

Describe the location of the liver

Answer 1

Upper right quadrant of abdomen between ribs 5-10

Question 2

Liver is suspended between stomach and anterior abdominal wall by what two peritoneal ligaments?

Answer 2

1) Lesser Omentum - bet. liver and stomach

2) Falciform ligament - bet liver and ant. abd. wall

Question 3

The Lesser Omentum contains what?

Answer 3

Hepatic blood vessels and bile ducts

Question 4

The visceral peritoneum covers the liver except for what area?

Answer 4

The bare area on top of the liver that is attached to the diaphragm and surrounded by coronal ligament

Question 5

T or F?

The lobes of the liver (right, left, quadrate, and caudate) are separated by functional unit.

Answer 5

FALSE

The lobes of the liver are demarcated by blood vessels and ligaments.

Question 6

The ligamentum teres is a vestige of what?

Answer 6

The umbilical vein, which carries blood from placenta to fetus.

Question 7

What is the Porta Hepatis and what does it contain?

Answer 7

The “Hilium” of the liver. Contains bile ducts, hepatic artery, portal vein

Question 8

What are the functions of the liver?

Answer 8

Macrophages (Kupffer cells) eat bacteria
Metabolism (protein, fat, carb)
Store vitamins and iron
Detoxify drugs, hormones, etc
Secrete bile

Question 9

The hepatic artery brings __________ blood from the aorta via the _________ artery

Answer 9

oxygenated, celiac

Question 10

Portal vein brings blood high in __________ and low in ___________ to the liver from the _________, _________, and ____________ veins

Answer 10

nutrients; oxygen; gastric, splenic, mesenteric

Question 11

What kind of cells line sinusoids in the liver? What are the functions of these cells?

Answer 11

Hepatocytes.

They detoxify, metabolize, store iron & vitamins, etc

Question 12

Hepatic veins bring blood out of the ________ portion of the liver into the ________________.

Answer 12

Superior

Inferior vena cava

Question 13

How are hepatocytes arranged?

Answer 13

Hexagonal arrangement (classic lobule)

Question 14

At each corner, the portal areas (triads) contain what structures?

Answer 14

Hepatic artery, portal vein, bile canaliculus

Question 15

What lies in the middle of the classic lobule?

Answer 15

Central vein

Question 16

What is the functional unit of the liver?

Answer 16

Liver acinus

Question 17

Describe the relationship of structure to function in the liver acinus.

Answer 17

Hepatocyte efficiency depends on proximity to blood supply. An acinus includes the central area between two adjacent lobules. The innermost zone receives most O2 and nutrients. The outermost zone receives the least.

Question 18

Which zone of the acinus is the primary site of detoxification of alcohol and drugs? How does this affect it?

Answer 18

Zone 3; Susceptible to hypoxia and toxic damage (in conjuction with lower O2 and nutrient supply)

Question 19

Trace the flow of lymph through the lobule

Answer 19

sinusoids –> space of Disse –> channel to either thoracic duct or inf vena cava

Question 20

What is portal hypertension? What symptoms does it cause?

Answer 20

Back pressure of blood into portal circulation due to flow obstruction. Causes varicosities in portal-caval anastomoses (eg hemorrhoids, caput medusae and esophageal varices)

Question 21

How does Acites develop?

Answer 21

Portal htn increases lymph flow into space of Disse. Excess lymph seeps through the visceral layer of peritoneum and creates fluid build-up in the peritoneal cavity (i.e. ascites)

Question 22

How does the body compensate for acites?

Answer 22

Drop in blood volume stimulates renal salt and water retention until blood volume is restored.

Question 23

What is fatty change? How does fatty change occur in the liver?

Answer 23

Intracytoplasmatic accumulation of TAG.
First, hepatocytes present multiple small fat droplets around the nucleus (microvesicular fatty change). In late stages, the size of fat droplets increases, pushing the nucleus to the periphery of the cell (macrovesicular fatty change)
From wikipedia

Question 24

Where does bile originate and how does it flow out of the liver?

Answer 24

Secreted by hepatocytes, flows through canaliculi towards bile ducts

Question 25

What makes up bile?

Answer 25

Bile acids, phospholipids, cholesterol Bicarbonate (also secreted from hepatocytes) Bile pigments (bilirubin and melatonin)

Question 26

What is the function of melatonin in bile?

Answer 26

Antioxidant. Protects the GI mucosa against the damaging effect of bile acids.

Question 27

What structures meet to ultimately form the common bile duct?

Answer 27

``` Right and Left Hepatic Ducts join to form the Common Hepatic Duct which meets with the Cystic Duct from the gall bladder. Together they flow into the Common Bile Duct ```

Question 28

Describe the structures that meet to allow bile and pancreatic secretions to flow into the sm int.

Answer 28

Main Pancreatic Duct = outflow from pancreas Hepatopancreatic Ampulla = junction of Common Bile Duct and Pancreatic Duct Major Duodenal Papilla secretes bile and pancreatic secretions into duod.

Question 29

What are the parts of the gall bladder?

Answer 29

Body, neck, fundus, cystic duct

Question 30

How is bile stored in the gall bladder? What else happens to the bile?

Answer 30

In fasting state, Sphincter of Oddi (major duod. papilla) is closed. Creates backflow of bile to fill gall bladder. It becomes more concentrated due to water absorption through the mucosa.

Question 31

What is involved in the release of bile from the gall bladder?

Answer 31

Fats trigger release of CCK which contracts g.b. wall. Vagus n. increases bile flow and contracts g.b.

Question 32

What drugs are used to alter bile production?

Answer 32

Cholegog triggers release of bile. | Choleretics increase production (and maybe fluidity) of bile.

Question 33

Describe the changes in bile flow that happen on a daily basis

Answer 33

G.B. has reversal of flow that happens about 4-5 hrs after last meal. The sphincter of oddi closes and bile backs up into cystic duct, which has spiral folds that create a reservoir for bile.

Question 34

What is cholelithiasis? What are the symptoms?

Answer 34

Gall stones. Referred pain between the shoulder blades or below the right shoulder.

Question 35

What is cholecystitis? What are the symptoms?

Answer 35

Inflammation of gall bladder. Referred pain to right scapula.

Question 36

What are the functions of CKK?

Answer 36

``` Promote fat digestion by Emptying g.b. Pancreatic secretions Gastric slowing Intestinal peristalsis ```

Question 37

What are the functions of Secretin?

Answer 37

Promote HCO3 secretion from bile ducts pancreatic ducts Brunner's glands

Question 38

What is the primary cause of gall stones?

Answer 38

80% of gall stones due to cholesterol forming crystals. First sludge, then gravel, then stones.

Question 39

What are other factors in the formation of gall stones?

Answer 39

Excess absorption of water (over concentrates bile) Excess secretion of cholesterol Inflammation of g.b. epithelium Stasis of g.b. smooth muscle layer (progesterone, very low fat diet, water fast) Reduction in terminal ileum absorption of bile salts leads to thickening of bile --> gall stones

Question 40

How do lecithin and bile salts affect bile?

Answer 40

Both serve to increase the solubilize cholesterol. If cholesterol stays in solution --> no gall stones