Pancreas, Liver, And Gallbladder 💚

Question 1

Pancreatic juice is rich in _____ and _____

Answer 1

Digestive enzymes

Bicarbonate

Question 2

Is pancreas more of an exocrine or endocrine organ?

Answer 2

Exocrine 90%

Question 3

What cells in the pancreas release exocrine secretions?

Answer 3

Acinar cells

Duct cells

Question 4

Exocrine pancreas is organized like what organ?

Answer 4

Salivary gland

Question 5

What are the functions of pancreatic juice?

Answer 5

Neutralize acids from the stomach

Provide enzymes for digestion of food

Question 6

How does pancreatic juice neutralize acids from he stomach?

Answer 6

Bicarb

Question 7

Most intestinal enzymes have optima pH near ____

Answer 7

7

Question 8

What enzymes are in pancreatic juice?

Answer 8

Amylases- break down starch

Lipases- digest TGs, PLs and cholesterols

Proteases- break down proteins to AA’s and smaller peptides

Question 9

What do acinar cells do?

Answer 9

Secrete enzymatic component

Question 10

What do ductal cells do?

Answer 10

Modify the juice by removing Cl- and adding HCO3- the creation of this HCO3- helps offset the alkaline tide created by the parietal cells in the stomach, because it also yields an H+ that gets put into the blood

Question 11

Where does the aqueous portion of pancreatic juice come from?

Answer 11

Centroacinar cells

Ductal cells

Question 12

As the pancreatic juice gets secreted faster and faster, how does the composition of it change?

Answer 12

The juice gets MORE HCO3- and LESS Cl-

Na+ and K+ are unchanged

Question 13

What are the 3 phases of pancreatic stimulation?

Answer 13

Cephalic

Gastric

Intestinal **most important

Question 14

How much can the cephalic and gastric phase increase pancreatic secretion?

Answer 14

Only 10-15%

Question 15

What is the MOST important phase of pancreatic stimulation

Answer 15

Intestinal phase- controls 80%

Question 16

Does the intestinal phase affect the pancreas via Hormonal or Nervous mechanisms?

Answer 16

Hormonal!**

CCK and Secretin

Question 17

What causes the duodenum to release CCK?

Answer 17

fatty acids and amino acids in duodenal chyme

Question 18

Where does CCK come from?

Answer 18

I cells (of the duodenum)

Question 19

Where does Secretin come from?

Answer 19

S cells (of duodenum)

Question 20

What causes the release of Secretin?

Answer 20

H+ in the duodenum

Question 21

What is “nature’s antacid?’

Answer 21

Secretin

(In response to H+, it causes ductal cells in pancreas to increase the aqueous component of pancreatic juice, which contains bicarb)

Question 22

How does CCK get to the pancreas?

Answer 22

Via circulatory system

Question 23

What does CCK do?n

Answer 23

Stimulates the acinar cells to increase enzyme secretion

Little effect on aqueous secretion

Question 24

How much does secretin stimulate enzyme secretion?

Answer 24

Not much

Question 25

What are the functions of the liver?

Answer 25

Regulate blood glucose (stores glycogen) 🍭 Regulates vascular volume (albumin, reservoir for blood) Detoxification and conjugation Cholesterol metabolism (making bile) Synthesis of plasma proteins Digestion and absorption of fats*

Question 26

What does bile help you do?

Answer 26

Fat emulsification and digestion Transport and elimination of cholesterol Fat absorption (Breaks up big fat droplets into smaller ones)

Question 27

What are the 2 blood sources for the liver?

Answer 27

Hepatic portal system- nutrient rich but oxygen poor Hepatic artery- oxygenated blood

Question 28

The _____ is the fundamental unit of the liver

Answer 28

Lobule

Question 29

What is in the very middle of a lobule?

Answer 29

Central vein

Question 30

What is in the portal space?

Answer 30

Hepatic portal vein Hepatic artery Bile duct

Question 31

What cells secrete bile into the bile canaliculi?

Answer 31

Hepatocytes

Question 32

What is in the sinusoids within lobules?

Answer 32

Blood from the portal vein

Question 33

Are all of the cells in the sinusoidal endothelium continuous with each other?

Answer 33

No, they have large fenstrations that allow proteins through

Question 34

Is the pathway of blood within the liver lobules high or low resistance

Answer 34

Low resistance GI > portal vein > sinusoids > central vein > vena cava

Question 35

What happens to the blood as it moves from the portal vein toward the central vein?

Answer 35

Hepatocytes reabsorb bile and transfer it to bile canaliculi

Question 36

Do the bile canaliculi come into contact with the sinusoids?

Answer 36

NO!! NO !!! NO! NO! ON!OONONONO he said this 3746 times!! NOOOOO direct passage from blood bile!! MUST be moved through the hepatocyte

Question 37

What are Kupffer cells?

Answer 37

Phagocytic cells inside the liver lobules | Not sure this is important

Question 38

Bile canaliculi are separated from sinusoids by _______

Answer 38

Tight junctions

Question 39

Materials entering bile canaliculi must ____________

Answer 39

Pass through the hepatocyte | ****************

Question 40

What are the components of bile?

Answer 40

Bile salts (50%) Phospholipids (40%) Cholesterol (4%) Bile pigments (2%)

Question 41

What cells make bile acids and bile salts?

Answer 41

Hepatocytes

Question 42

What determines how much new bile acid is synthesized?

Answer 42

The amount of bile salts returned to liver via enterohepatic circulation

Question 43

How much bile salt is in the body ? Does it ever change?

Answer 43

2-4g. TIGHTLY regulated

Question 44

What are the 3 forms of bile?

Answer 44

Primary (hepatic origin) Secondary (bacterial origin) Conjugated (can be primary or secondary)

Question 45

How does primary bile salt get turned into secondary bile salt?

Answer 45

Bacteria change it

Question 46

What is the purpose of conjugating bile salts?

Answer 46

Makes it more soluble in the duodenum

Question 47

What groups are added onto bile salts to conjugate them?

Answer 47

Glycine or Taurine

Question 48

Why does conjugating bile salts make them more soluble in the duodenum?

Answer 48

It lowers the pK from 7 to <4. Allows them to remain hydrophobic bile salts at duodenal pH (3-5)

Question 49

Do phosophilpids in bile get recirculated?

Answer 49

No

Question 50

Are phospholipids water soluble?

Answer 50

No, but they are amphipathic

Question 51

What purpose do phospholipids serve in bile salts?

Answer 51

Increase ability of bile salts to solubilize cholesterol

Question 52

What is the most important bile pigment?

Answer 52

Bilirubin

Question 53

Where does bilirubin come from?

Answer 53

Porphyrins from senescent RBCs

Question 54

What form is bilirubin in when it’s in the bile: conjugated or uinconjugated?

Answer 54

Conjugated ONLY

Question 55

What group gets added onto bilirubin to conjugate it?

Answer 55

Glucuronic acid | Tags it for removal by the kidney= reason peepee is yellow

Question 56

What gives bile its yellow color?

Answer 56

Bilirubin glucuronide | Aka conjugated bilirubin

Question 57

What is this: | visually detectable buildup of bile pigments (bilirubin) in the blood

Answer 57

Jaundice

Question 58

What are the 3 types of jaundice?

Answer 58

Prehepatic (hemolytic) Hepatic (liver disease) Posthepatic (obstructive)

Question 59

What causes prehepatic jaundice?

Answer 59

Excessive breakdown or RBCs which creates too much bilirubin for the liver to excrete Ex: pernicious anemia, infants

Question 60

What causes hepatic jaundice?

Answer 60

Liver is diseased and unable to deal with the normal load of bilirubin Ex: cirrhosis, Gilbert’s syndrome (deficiency of conjugating enzyme)

Question 61

What causes posthepatic jaundice?

Answer 61

Obstruction of the bile duct Ex: gallstone, pancreatic cancer

Question 62

What are the 2 ways bile salts aid fat digestion?

Answer 62

1. Emulsifying large fat droplets (detergent action) | 2. Forming small lipid aggregations called micelles

Question 63

Why do we need to emulsify fats?

Answer 63

Increases surface area of fat droplets that is available for attack by pancreatic lipase

Question 64

After emulsification, what keeps all the small fat droplets from just reconvening?

Answer 64

They repel each other due to negative charges of bile salts?

Question 65

What are micelles?

Answer 65

Aggregations of amphipathic bile components that form spontaneously in aqueous environments Hydrophilic portions face outward and hydrophobic portions face the interior (cholesterol, phospholipids, FFA’s, etc)

Question 66

What are the functions of micelles?

Answer 66

Act as lipid “shuttles” to deliver to enterocyte Increase lipid solubility in chyme

Question 67

What is happening in the gallbladder in the inter digestive period (aka not processing a meal)

Answer 67

Bile flows to gallbladder and concentrated Sphincter of Oddi Contracts** to prevent bile flow into duodenum

Question 68

What is happening to the gallbladder during the digestive period?

Answer 68

Gallbladder contracts (CCK) Sphincter of Oddi relaxes (CCK) =Continuous bile duct secretion for as long as CCK is present in the bloodstream

Question 69

What is the primary regulator of release of bile from the gallbladder?

Answer 69

CCK****