Digestive System Flashcards
Pseudopodia
temporary protrusions of the cell membrane found in protists for cell movement and feeding.
What are the 3 accessory organs in digestive system
pancreas, liver, and gallbladder
Mechanical digestion and Chemical digestion begin where in the body?
Mouth
What enzyme is used in chemical digestion?
Salivary amylase
What does salivary amylase break down? What does it break down into?
Breaks down starch into maltose (glucose + glucose)
Maltose is composed of what
glucose + glucose
What types of muscle does the esophagus have and in what specific location?
upper third: skeletal muscle, lower third: smooth muscle, middle third: mix of smooth/skeletal
Where does food enter the stomach through?
Cardiac sphincter
The stomach lining is filled with ______ ______ leading to _____ ______
gastric pits, gastric glands
Food entry causes the stomach to ______, signaling ____ _____ to release ______
distend, G cells, gastrin
What are gastrin’s two functions?
- Stimulates parietal cells to release acidic gastric juice
- Stimulates chief cells to secrete gastric lipase & pepsinogen→pepsin
Parietal cells to release _____
Acidic gastric juice (HCl)
What does gastric lipase do? Where is it found?
- Breaks down fats to fatty acids + glycerol
- Found in stomach
What does pepsinogen do? Where is it found?
- Activates to pepsin in acid
- It is a zymogen
- Found in stomach
What is a zymogen?
an inactive enzyme precursor that prevents digestion of cell itself
What does pepsin do? Where is it found?
- Cleaves peptide bonds (proteins → amino acids)
- Found in stomach
What is chyme? What structure does it exit through and to?
- Acidic, semi-digested food
- Exits to the small intestine via the pyloric sphincter
3 parts of the small intestine?
DJ Eye (I)
Duodenum, Jejenum, Ileum
_______ cells secrete _______ to protect the epithelial lining from acidic chyme
Goblet, mucus
Chyme triggers the release of what in the small intestine?
Secretin
What is secretin function? What structure does it utilize to release its ions?
Stimulates the pancreas to release basic bicarbonate ions (HCO3-) into the duodenum via the pancreatic duct.
Why would the small intestine release CCK?
in response to detecting proteins and fats entering the small intestine
What 3 things occur after CCK is released?
- Slows gastric emptying
- Stimulates the pancreas to release digestive enzymes (trypsin)
- Gallbladder releases bile into the duodenum
What molecule neutralizes the acidic chyme? Released by what?
HCO3-
Pancreas
Main function of bile?
Bile is produced by what? Stored in what?
- Important for absorption of fats in diet and emulsifies fats
- Liver
- Galbladder
Inside the villus, nutrients are absorbed into ____ _______ and fats into _______.
- blood capillaries
- lacteals
Villi are made up of what?
enterocytes
Liver functions
PUSHDoG
Protein synthesis
Urea synthesis
Storage
Hormone synthesis
DetOxification
Glucose/Fat Metabolism
What 3 things does the pancreas release
HCO3-
pancreatic amylase
proteases
Pancreatic amylase does what
starch → maltose
Proteases do what
What are the 2 important proteases?
Digest proteins → amino acids
- Trypsin and chymotrypsin
In the duodenum, ______ converts trypsinogen to trypsin
Enteropeptidase
______ converts chymotrypsinogen to chymotrypsin.
Trypsin
Crypts are ______ contain cells that secrete _____ and produce new ______ cells for the lining.
invaginations, enzymes, epithelial
The liver destroys….?
Using what kind of cells?
erythrocytes and bacteria
Kupffer cells
Explain what Kupffer cells break down
Break down hemoglobin in RBCs to bilirubin for secretion in bile
Glycogenesis
converts excess glucose into glycogen for storage in the liver
Glycogenolysis
breaks down glycogen to glucose for bodily use (between meals).
Gluconeogenesis
converts glycerol and amino acids into glucose when glycogen stores are depleted.
In the liver, what is converted to urea for safer excretion?
Ammonia
Water and mineral absorption occur where?
At the cecum
In the colon ______ absorption is completed, hardening feces.
water
Large intestine 3 main functions
- Water absorption
- Mineral absorption
- Vitamin production & absorption
Explain the 3 things bacteria does in the large intestine
- Bacteria produce vitamins B and K (absorbed)
- Metabolize bile acid
- Ferment fiber
A healthy microbiome will have ______ levels of all the bacteria needed for bile acid metabolism, while an _____ microbiome will not, impairing function
sufficient, unhealthy
What produces gastrin?
G cells of the stomach
What produces secretin?
Duodenum
What produces CCK?
Duodenum
What produces gastric lipase?
Chief cells
What produces pancreatic amylase?
pancreas
What produces pepsinogen?
Chief cells of the stomach
What produces trypsinogen and chymotrypsinogen?
pancreas
What produces enteropeptidase? Function?
duodenum
Trypsinogen → Trypsin
Over 99% of bacteria in the large intestine are ______ ________
obligate ANaerobes
also facultative ANaerobes
where are goblet cells found?
Small intestine
