L6 liver

Question 1

what are the functions of the liver

Answer 1

bile production, process blood, detoxes blood, store glycogen, fetus erythrocyte production, synthesis amino acid/lipid/complex carb, synthesis of proteins

Question 2

liver position and size

Answer 2

inferior to diaphragm and is protected by ribcage, right side, 1.4 kg

Question 3

what is the bare area

Answer 3

superior, slightly posterior surface, touches diaphragm, not covered by visceral peritoneum

Question 4

what is falciform ligament

Answer 4

mesentery, separates the two lobes suspends liver from the diaphragm and the anterior body wall

Question 5

what is the round ligament

Answer 5

ligamentum teres, remnant of umbilical vein

Question 6

where is lesser omentum

Answer 6

in fissure between L R lobes

Question 7

what is porta hepatis

Answer 7

contains hepatic artery and hepatic portal vein

Question 8

what are the segments of the liver

Answer 8

8 segments, clockwise from the caudate lobe, each section has its own branch of portal vein, hepatic artery, and bile duct

Question 9

what are lobules

Answer 9

hexagonal shaped units of hepatocytes that surround a central vein. each lobule contain multiple bile duct, portal vein and hepatic artery that form a portal triad. blood flows in from the artery and passes through the sinusoids to allow efficient exchange

Question 10

what is the hepatic macrophage

Answer 10

stellate, star shaped, removed bacteria and damaged erthryocytes. resides in sinusoids

Question 11

hepatocyte functions

Answer 11

can produced 900ml of bile/day, stores fat soluble vitamins like A, converts ammonia to urea, protein and glycogen synthesis, secrete GF if liver injured

Question 12

gall bladder

Answer 12

“potential space” organ, mucosa expands to fill, up to 10x4cm when fully expanded, stores and concentrates bile, mucosa contracts to expel contents

Question 13

gall bladder micro anatomy

Answer 13

microvilli on the columnar epithelium to increase SA, then lamina propria that contains blood vessels, lymphatics and nerve fibres, then the smooth muscle layer which helps to contract to expel bile, then mucosa

Question 14

what is the composition of bile

Answer 14

bile salts: to emulsify fats, can be recycled via the enterohepatic circulation
bile pigments – bilirubin: is a product of hemoglobin breakdown, metabolized by gut flora, stercobilin gives feces the brown color
cholesterol: excess secreted in bile
triglyceride, phospholipids and electrolytes

Question 15

enterohepatic circulation of bile acids

Answer 15

• 0.5g/day produced
• secreted into bile and stored in gall bladder
• when food enters the SI, cholecystokinin (CCK) hormone is released and bile is secreted into intestine
• some bile is passively reabsorbed in the upper intestine
• most bile reabsorbed in the ileum via ASBT (apical-dependent bile salt transporter)
• then to liver via portal vein
• 95% of bile recirculated back to liver and rest is excreted with feces

Question 16

CCK

Answer 16

cholecystokinin, synthesized by enteroendocrine cells, mostly in duodenum and jejunum

Question 17

hormones involved in hunger and satiety

Answer 17

CCK, ghrelin, glucagon, insulin, adrenaline, leptin

Question 18

nerve involved in hunger and satiety

Answer 18

vagal nerves

Question 19

ghrelin

Answer 19

hormone released by the stomach that stimulates hunger, levels increase before meals and decrease after eating

Question 20

leptin

Answer 20

hormone produced by fat cells, acts on the brain to suppress appetite and increase energy expenditure, higher levels indicate satiety

Question 21

gall stones

Answer 21

crystallization due to excess cholesterol or lack of bile salts,
symptoms include: pain during gallbladder contraction, bile duct blockage leading to jaundice

Question 22

treatment of gallstones

Answer 22

removal, dissolution, sonication

Question 23

hepatitis and causes

Answer 23

inflammation of liver, caused by viruses HepA -> HepF
HepA and E are transmitted via GI
HepB and C are transmitted via blood contact
can also be caused by drugs, alcohol, and autoimmunity

Question 24

symptoms of hepatitis

Answer 24

flu-like, jaundice, appetite loss, swelling of liver and spleen, may be asymptomatic

Question 25

alcoholic liver disease

Answer 25

risk factors: drinking without food, low vit A and E, genetics
how?
- fatty liver (accumulation of fatty acids)
- alcoholic hepatitis
- cirrhosis of liver (end stage of inflammation, collagen, fibrosis, liver failure)

liver can regenerate, but if toxic agent persists, it won’t.

Question 26

cirrhosis

Answer 26

progressive liver disease characterized by the replacement of healthy liver tissue with scar tissue
typically the end stage of various liver diseases eg chronic hepatitis, alcohol-related liver disease, NAFLD, autoimmune liver diseases

Question 27

cirrhosis symptoms

Answer 27

• fatigue and weakness
• jaundice
• loss of appetite and weight loss
• abdominal pain and swelling
• easy bruising and bleeding
• spider veins
• mental confusion or changes in personality

Question 28

cirrhosis treatments

Answer 28

managing the underlying cause, relieving symptoms, and preventing complications, liver transplant

Question 29

portal hypertension

Answer 29

scar tissue obstructing blood flow through hepatic portal system.
small veins connecting to vena cava may burst due to pressure
caused by thrombosis and liver cirrhosis

Question 30

symptoms of liver hypertension

Answer 30

blood vomit
esophageal varices (enlarged and swollen veins that develop in the lower part of the esophagus)
caput medusae (dilated and swollen veins that radiate outward from the belly button)
ascites (accumulation of fluid in peritoneal cavity)