Chapter 23: Digestive System Flashcards
The liver _____________ the blood, and makes blood _____________
filters, proteins
The liver gets rid of _____________
hydrophobic waste
The liver metabolizes _____________, _____________, and _____________. As well as detoxes _____________
fats, carbs, and proteins, ethanol detox
The liver stores _____________ and makes _____________
stores fat soluble vitamins and makes bile
Gall bladder functions:
stores and concentrates bile (bile breaks down or emulsifies fat)
_____________ breaks down fat into smaller molecules surrounded by _____________ which allows for easier digestion
bile, micelles
What are the 4 exocrine enzymes that the pancreas secretes?
lipase (fat), protease (protein), amylase (carbs), and nuclease (nucleic acid, DNA, RNA)
What neutralizes the pH of chyme and what organ secretes it?
bicarbonate (HCO3-), pancreas
Where are pancreatic enzymes and bicarbonate secreted?
into the small intestine via the hepato-pancreatic sphincter (aka the sphincter of oddius)
What are the 5 layers of the alimentary canal (from inside to outside)?
lumen, mucosa, submucosa, 2 layers of smooth muscle, serosa
What is lumen?
the hollow where the food is stored in the alimentary canal
What is the function of mucosa?
the protective layer (to ensure the organ doesn’t get digested).
Submucosa contains _____________ in order to _____________
contains blood supply (capillaries, arteries, veins, lymph) to absorb nutrients
Serosa is made up of _____________
connective tissue
How does food move down the digestive tract?
due to peristalsis (muscles alternately contract and relax moving food down the pathway)
What are the functions of the mouth?
grind food, moisture, begin starch breakdown/starch digestion
What are the three structures in the mouth?
teeth, salivary glands, tongue
What exocrine enzymes are secreted in the mouth?
saliva which is made up of amylase (carb breakdown) and lysozyme (kills some bacteria)
What endocrine enzymes are secreted in the mouth?
none
What is the function of the esophagus?
tube that brings food to the stomach
What is the structure of the esophagus?
starts as skeletal muscle, ends at stomach as smooth muscle, cardiac sphincter (aka gastroesophageal sphincter)
What connects the esophagus to the stomach?
cardiac sphincter (aka gastroesphageal sphincter)
What exocrine enzymes are released in the esophagus?
none
What endocrine enzymes are released in the esophagus?
none
What are the functions of the stomach?
stores and grinds food, some limited digestion
What are the two structures of the stomach?
gastric glands (or pits) pyloric sphincter
What connects the stomach to the small intestine?
pyloric sphincter
What three types of cells make up a gastric gland? (from deepest to stomach surface?
chief cells, parietal cells, mucous cells
What do chief cells secrete?
pepsinogen
What do parietal cells secrete?
HCL
The exocrine enzymes secreted in the stomach are _____________ and _____________. Together the make _____________.
pepsinogen, HCL. Together they make pepsin (breaks down proteins)
The endocrine enzyme that is released into the stomach is _____________ which is secreted by _____________
gastrin, secreted by G cells
What does gastrin activate?
gastric glands
What are the functions of the small intestine?
where most digestion occurs, and food absorption
What are the three sections of the small intestine (in order- top to bottom)
Duodenum, jejunum, ileum)
What are the two main structures in the small intestine?
circular folds (aka plicae circularis) and peyeris patches
WHat are peyeris patches and where do they appear?
lymphoid tissue, appear toward end of small intestine
What are the structures on the circular folds and what are their functions?
villi, increase surface area to absorb nutrients
What structures make up the “brush border”? And where are they located?
microvilli, located on the villi in the small intestine
List some examples of exocrine brush border enzymes and what they do.
ex) protease, lipase, amylase, nuclease. They breakdown molecules so they are easily digested (like a disaccharide into tow monosaccharides for absorption)
Tripsinogen and enterokinase make _____________. (similar to pepsinogen and HCL in gastic glands)
trypsin (small intestine exocrine enzyme), which activates the pancreas (
The lacteal system take nutrients from the small intestine to the liver via the _____________
hepatic portal system
What are the three endocrine enzymes secreted in the small intestine?
CCK, enterogasterone, and secretin
What does the enzyme CCK do?
is released in the duodenum and makes the gall bladder secrete bile (to break down fat)
What does the enterogasterone do?
slows down stomach motility
What does secretin do?
goes to the pancreas and secretes bicarbonate (neutralizes chyme)
What are the functions of the large intestine?
stores waste, water absorption, contains bacteria that hep break down vitamins (like vitamin K)
What 4 structures are in the large intestine?
ileocecal sphincter, internal anal sphincter, external anal sphincter, and lacteal vessels
What does the ileocecal sphincter connect? and when does it open?
the small intestine to the large intestine (opens when food enters the stomach)
The internal sphincter is made of _____________ and the external sphincter is made of _____________.
smooth muscle, skeletal muscle
What do lacteal vessels do?
collect lipids in the large intestine
What exocrine enzymes are released in the large intestine?
none
What endocrine enzymes are released in the large intestine?
none
_____________ cells are found in every region of the digestive tract.
goblet cells
What do goblet cells do?
make mucin (mucin + water=mucus)
Which three arteries make up the portal triad?
- portal venule (brings blood into the cell)
- arteriole (brings oxygenated blood into the cell)
- Bile duct: brings bile out of liver cell to the gall bladder for storage
What do macrophages do?
destroy bacteria
What takes nutrient rich blood to the liver from the small intestine?
the hepatic portal system
liver cell is also known as a _____________
hepatocyte
central veins of liver cells lead to the _____________ vein to _____________ the liver
hepatic vein, drain the liver
For more on the liver cell look on page 590 of the lab manual
;)
What are 3 specific modifications of the small intestine histology?
Villi, microvilli, and intestinal crypts
Goblet cells secrete ________.
mucus
Bile is necessary for the digestion and absorption of _____.
Fats
Its secretions moistens ingested food, cleanses and protects the mouth
salivary glands
its secretions emulsifies fat for digestion and absorption of fat
The liver
Its secretion digest major foodstuffs, and neutralize acid
Pancreas
