(F) L5: GITP: Small Intestine Flashcards
The SI is where (initial/intermediate/final) digestion happens
Final
Absorption in the SI is possible through what kind of diffusion and transport? (2)
- Passive diffusion
- Active transport
Parts of the SI
- First portion
- Shortest region: 10 inches
- Where secretions are emptied from the stomach, gallbladder, and pancreas through the bile ducts
- Calcium, Magnesium, and Iron are absorbed
Duodenum
Parts of the SI
- 3 feet long and is the major site of nutrient absorption
- Where fat and water-soluble vitamins, amino acids, and monosaccharides are absorbed
- Made up of circular folds (villi) which are made up of microvilli containing capillaries and lacteals where fatty acids and lipids are absorbed
Jejunum
Parts of the SI
These are made up of microvilli which contains capillaries and lacteals, wherein fatty acids and lipids are absorbed
Villi
Parts of the SI
10 cm
A. Jejunum
B. Duodenum
C. Ileum
D. Neither
D. Neither (the duodenum is 10 INCHES long)
Parts of the SI
3 feet long
A. Jejunum
B. Duodenum
C. Ileum
D. Neither
A. Jejunum
Parts of the SI
- The longest part: 6 feet
- It joins the large intestine (proximal to the cecum) where water and electrolytes are absorbed
- Where B12 and bile acids are absorbed
Ileum
Parts of the SI
B12 and Bile Acids are absorbed
A. Jejunum
B. Ileum
C. Large Intestine
B. Ileum
Parts of the SI
Water and electrolytes are absorbed
A. Jejunum
B. Ileum
C. Large Intestine
C. Large Intestine
Parts of the SI
Longest portion: 6 feet long
A. Duodenum
B. Jejunum
C. Ileum
C. Ileum
Digestion of Carbs in the SI
The only unit of carbohydrate that is absorbed by the intestine
Monosaccharides
Digestion of Carbs in the SI
This amylase is responsible for the initial digestion of CHO
Salivary
Digestion of Carbs in the SI
This amylase acts on partially digested carbohydrates responsible for the preliminary digestion of CHO
Pancreatic
Digestion of Carbs in the SI
What are the 2 isoenzymes of amylase?
Pancreatic and Salivary
Digestion of Carbs in the SI
This converts carbohydrates to become monosaccharides, digesting each particle into their simplest form which is absorbable by the intestine
Brush Border Enzymes (BBE)
Digestion of Carbs in the SI
A deficiency of Brush Border Enzymes leads to?
Malabsorption
Brush Border Enzymes
Acts on dextrin
Alpha Dextrinase
Brush Border Enzymes
Breaks down sucrose to glucose and fructose
Sucrase
Brush Border Enzymes
Breaks down lactose to glucose and galactose
Lactase
Brush Border Enzymes
Breaks down maltose to 2 glucose units
Maltase
Digestion of Carbs in the SI
This condition results from lactase deficiency and manifests with diarrheic stools, bloating, and metabolic acidosis
Lactose Intolerance
Digestion of Proteins in the SI
Protein digestion starts in the stomach with the aid of what?
Pepsin
Digestion of Proteins in the SI
Proteins are degraded into what for intestinal absorption?
Amino acids
Digestion of Proteins in the SI
Refers to the group of enzymes consisting of Trypsin, Chymotrypsin, and Elastase
Endopeptidases
Digestion of Proteins in the SI
Refers to the group of enzymes consisting of Carboxypeptidase and Aminopeptidase
Exopeptidases
Digestion of Proteins in the SI
Brush Border Enzymes (BBEs) are responsible for digesting proteins into its absorbable form such as? (3)
- Polypeptides
- Peptides
- Amino acids
Digestion of Proteins in the SI
Brush Border Enzymes (BBEs) are those of what 2 enzymes?
- Aminopeptidase
- Dipeptidase
Digestion of Lipids in the SI
These enzymes split up TAG and phospholipids
Lipases
Digestion of Lipids in the SI
What are the 3 types of lipases?
- Lingual
- Gastric
- Pancreatic
Digestion of Lipids in the SI
- The most important lipase
- A deficiency of this leads to malabsorption and manifests as steatorrheaic stool
Pancreatic lipase
Digestion of Lipids in the SI
A deficiency of pancreatic lipase leads to malabsorption and manifests as steatorrheaic stool which can also be seen in what parasite infection?
Giardiasis
Digestion of Lipids in the SI
This process is due to the action of bile acids which acts on fat by inserting micelles in the lipids, making them water-soluble
Fat emulsification
Digestion of Lipids in the SI
Fats need to be (blank) in order for them to be absorbed by the body, via the breakage of micelles
Water-soluble
Digestion of Lipids in the SI
This is the specific area where fats are absorbed
Lacteals (in the jejunum)
Digestion of Nucleic Acids
This is made up of a nucleoside and a phosphate group
Nucleotides
Digestion of Nucleic Acids
This is when a sugar backbone combines with nitrogenous bases (A, G, T, C)
Nucleosides
Digestion of Nucleic Acids
Nucleic acids are degraded into the sugar portion known as?
Nucleotides
Note: It also has the bases and phosphate groups which are absorbable
Digestion of Nucleic Acids
Produced in the pancreas
A. Ribonucleases
B. Deoxyribonucleases
C. Both
D. Neither
C. Both
Digestion of Nucleic Acids
Aside from ribonucleases and deoxyribonucleases, what are the other 2 enzymes?
- Phosphatases
- Nucleases
Digestion of CHO
A. Salivary amylase
B. Pancreatic amylase
C. Both
D. Neither
C. Both
Digestion of CHO
Digestion of CHO (enzymes)
A. Maltose
B. Lactase
C. Both
D. Neither
B. Lactase (maltose should be MALTASE)
Digestion of CHO (enzymes)
A. Beta dextrinase
B. Alpha dextrinase
C. Both
D. Neither
B. Alpha dextrinase
Digestion of CHON
A. Endopeptidase
B. Exopeptidase
C. Both
D. Neither
C. Both
Digestion of CHON
A. Aminopeptidase
B. Tripeptidase
C. Both
D. Neither
A. Aminopeptidase (should be dipeptidase)
Digestion of lipids:
A. Lingual lipase
B. Gastric lipase
C. Gallbladder lipase
D. A and B
E. B and C
D. A and B (the other is pancreatic lipase)
Digestion of lipids:
A. Phosphatases
B. Nucleases
C. Both
D. Neither
D. Neither (both are for the digestion of nucleic acids)