22-3: Accessory Organs

Question 1

pancreas

Answer 1

thin oblong accessory gland that lies deep to the greater curvature of the stomach in the LUQ; is a heterocrine organ (both exocrine and endocrine)

Question 2

islets of langerhans

Answer 2

endocrine cells that secrete the hormones insulin and glucagon

Question 3

acinar cells

Answer 3

cluster of exocrine cells that secrete a water mixture of digestive enzymes called pancreatic juice

Question 4

main pancreatic duct

Answer 4

tube that drains pancreatic juice from acini, and joins with the common bile duct from the liver before emptying into the duodenum

Question 5

pancreatic juice

Answer 5

contains:
bicarbonate ions (neutralize stomach acid and raise pH of chyme so intestinal enzymes can function)
pancreatic amylase (starch)
pancreatic lipase (lipids)
trypsin and chymotrypsin (protein - released in inactive form and activated in intestines since pancreas doesn't have a mucus membrane)

Question 6

pancreatic secretion is regulated by ___.

Answer 6

the ANS - vagus nerve - and 2 local hormones, secreted depending on what is entering the small intestine

Question 7

The presence of acid chyme in the duodenum causes the intestinal mucosa to secrete the __ ___, which causes ___.

Answer 7

hormone secretin directly into the blood; stimulates duct cells in pancreas to secrete pancreatic juice rich in bicarbonate

Question 8

The presence of fats and proteins in the duodenum causes the intestinal mucosa to secrete ____, which causes ___.

Answer 8

hormone cholecystokinin; stimulates acinar cells in pancreas to secrete pancreatic juice rich in digestive enzymes

Question 9

liver

Answer 9

large accessory organ just inferior to diaphragm and protected almost entirely by rib cage

Question 10

what are the four primary lobes of the liver?

Answer 10

right (largest)
left
caudate
quadrate

Question 11

falciform ligament

Answer 11

mesentary that separates the right and left lobes and attaches liver to diaphragm

Question 12

What is the digestive function of the liver?

Answer 12

produce bile for export to duodenum

Question 13

Where does bile go after it lives the liver?

Answer 13

leaves liver through several small ducts that unite to form the large common hepatic duct, which fuses with the cystic duct to form the common bile duct

Question 14

ampulla of Vader

Answer 14

bulb where the common bile duct unites with the pancreatic duct, which empties into the duodenum

Question 15

bile

Answer 15

an olive green liquid produced by the liver, not a hormone. acts as a fat emulsifier in the small intestine, breaking up fat into tiny particles that are more accessible to lipase

Question 16

What does bile contain?

Answer 16

water, cholesterol, bile salts, neutral fats, bile pigments, phospholipids, and electrolytes (eg. bicarbonate)

Question 17

bile salts

Answer 17

derived from cholesterol, role is to emulsify fats (not an enzyme). provide a larger surface area for digestive enzymes to work on

Question 18

bile pigments

Answer 18

biliruben is a waste product of the breakdown of RBCs; bacteria in the small intestine metabolize this to urobilinogen, giving feces their color

Question 19

when is bile production increased?

Answer 19

when GI tract contains chyme rich in fats

Question 20

gall bladder

Answer 20

small muscular sac resting in a shallow fossa on the ventral surface of the right lobe of liver

Question 21

What is the function of the gall bladder?

Answer 21

stores bile that is not immediately needed for digestion and concentrates it by absorbing some of its water

Question 22

How is bile directed into the gall bladder?

Answer 22

when the small intestine is empty, the ampulla of vader closes and bile backs up into the cystic duct into the gall bladder for storage

Question 23

How is bile released from the gall bladder?

Answer 23

when chyme high in fats enters the duodenum, the intestinal mucosa secrete the hormone cholecystokinin, which cases the muscular wall of the gall bladder to contract

Question 24

What are the three effects of CCK (cholecystokinin)?

Answer 24

1. contraction of gall bladder when chyme high in fats enters duodenum
2. stimulates secretion of pancreatic juice, high in digestive enzymes
3. opens ampulla of vater so bile and pancreatic juice can enter duodenum

Question 25

gall stones

Answer 25

too much cholesterol or too few bile salts leads to the formation of these sharp crystals, which obstruct flow of bile from the gall bladder