Large Intestine, Liver, Gallbladder, Pancreas Digestion

Question 1

How does blood run through liver?

Answer 1

Liver gets blood via two sources:
1. Hepatic Portal Vein
2. Heaptic Artery
Blood returns to the venous system through hepatic system through heaptic veins which empty into the inferior vena cava

Question 2

Hepatic Portal System

Answer 2

The hepatic portal vein receives the blood from the pancreas, stomach, small intestines, and spleen carries to liver
- Braches of hepatic portal system and the hepatic artey meet in spaces between lobules. Mixing in venous and aterial blood , after hepatocyte processing the blood empties into a central vein which leads to right and left hepatic veins.
- heart send blood through artery to capillary bed then back to veins and heart (general circulation)
- Blood from arteries reaches primary capillary bed attached to pan, stomach, spleen ( toxins, drugs put into blood) and nutrients , toxins absorbed. Then leads to hepatic portal vein which will go to the liver. Once reaches liver comes to another second capillary bed and everythiing filtered out. Clean blood gets returned to the vein and heart.
- then go to second capillary bed , back to heart

Question 3

Microscopic Liver Anatomy

Answer 3

• Filled with lobules
• Each lobule has central vein and surronded by heptacoytes
• space between plates hepatic sinouids lined with epithelium and brush boarder

Question 4

Function of Hepatocytes

Answer 4

1. Absorb glucose, amino acids, iron, vitamin, metabolsium
2. Absorb and remove waste (drugs , toxins, hormones, bile pigaments)
3. Secrete: lipoproteins, clotting proteins, angiotensiongen, albumin degradation
4. Glycogen–>glucose

Question 5

Kupffer Cells

Answer 5

Devor bacteria and clean out blood in liver

Question 6

Story of Bile in Liver

Answer 6

1. Hepatocytes secrete bile -> bile canaiculi –> empty into bile ductules–> right and left hepatic ducts –> common hepatic duct which joins with the cystic duct fro gallbldadder to form the common bile duct –> pancretic duct in expanded space called hepatopancretic ampulla–> hepatopancretic sphincter –> regulates amount of bile and pancretic juice into the dupdenum

Question 7

Bile Components

Answer 7

Choldestrol, bile acids, neutral acids, minereals
- Emuslification of fat via mechanical digestion to allow for increased SA
- Bile pigament: bilrubin (RBC byproduct)–> urobilogen–> sterocobulin (feecs color)

Question 8

Gallbladder and bile

Answer 8

• Gallbldadder sereves to store and concentrate bile
• Bile acids aid in lipid breakdown
• Bile enters the gallbladder by first filliing up bile duct and overflowing into gallbladder
• Majoirty of bile is reused

Question 9

How is bile recycled ?

Answer 9

1. Bile salts are secreted into the duodenum
2. Bile salts travel through small intestine, allow for lipid digestion and absorbtion
3. 95% bile are reasborbed ia illeium
4. Reabsobred bile salts travel via hepatic portal vein back into the liver , where it is then recycled.
   - High soluble fibers bind to bile salts and are not then reabsobred so they pass into small inte. prevents reabsobrtion of bile which lowers body cholesttrol and lower LDL.

Question 10

Pancreas

Answer 10

• Is concidered to be an endocrine and exocrine gland
  -It is endocrine as it secretes insluin and glucogon
• Exocrine mainly as it secretes pancretic juice ( water, enzymes, zymogens, bicarbonate) and conists of cells

Question 11

Cells of the pancreas

Answer 11

• Acinar cells: secrete enzymes , mucins
• Duct Cells: secrete buffer to chyme make bicarbonate

Question 12

Pancretic Juice Secretions: Protein Zymogens

Answer 12

• Entereopeptidase converts trypsinogen into trypsin ( trypsin hydrolses peptide bonds and activiates pancretic zymogens
• Just as pepsiongen needs to be activated by HCI to produce pepsin, Enteropeptidase converts trypsiogen to trypsin
• key enzyme to digest proteins Zymogens:
  1. Trypsinogen–> becomes trypsin to digest proteins
  2. Chymotrysinmogen–> chymotrypsin–> breakdown protein
  3. Procarboxypeptidase–> carboxypeptidase to remove amino’s

Question 13

Elatase

Answer 13

Breakdown of elastin

Question 14

Pancretic Lipase

Answer 14

Breakdown lipids

Question 15

Pancreatic Amylase

Answer 15

Breakdown carbohydrates.

Question 16

How is trypsin actvivated

Answer 16

• Enteropeptidase takes trypsinogen-> trypsin
• Trypsin breakdown protein and causes chymotrypsinogen –> chymotrypsin and procarboxypeptidase–> carboxypeptidase

Question 17

What regulates secretion of bile?

Answer 17

Three stimulu for the release of pancretic juice and bile.
- Acetycholine
- Cholecytsokinin
- Secretin