Physiology Block 3 Week 14 05 Digestion Flashcards Preview

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Flashcards in Physiology Block 3 Week 14 05 Digestion Deck (12)
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1

End result after digestion of:

-Carbohydrates
-Fats
-Proteins

Carbohydrates:
-end result is poly or disaccharides converted to monosaccharides

Fats:
-TG split into 3 fatty acids + glycerol

Proteins:
-split into AA

2

Carbohydrate Digestion

-Sucrose
-Lactose
-Starches

Sucrose:
--Disaccharide: Glucose + Fructose
--Enzyme: Sucrase (intestine)

Lactose:
--Disaccharide: Glucose + Galactose
--Enzyme: Lactase (intestine)

Starches:
--Large polysaccharides from non-animal sources (potatoes, grains): Maltose + 3-9 Glucose Polymers
--Enzymes: Ptyalin (saliva) and Pancreatic Amylase (pancreas)
--Secretin (acid secretion) allows pancreatic amylase to continue working

Maltose + 3-9 Glucose Polymers:
--Enzymes: Maltase and alpha-dextrinase

3

Protein Digestion

Pepsin:
-breaks down collagen (connective tissue of meats)
-10-20% protein digestion
-active at low pH

Pancreatic Secretions:
Trypsin and Chymotrypsin: breaks proteins into smaller peptides
Carboxypolypeptidase: cleaves ends of polypeptides to AA
Proelastase (converted to elastase): digests elastin fibers that hold meat together

Peptidase:
-on brush border of duodenum and jejunum
-results in AA, Dipeptides, and Tripeptides

Inside Enterocytes:
-break down di- and tripeptides into single AA

4

Fat Digestion

Lingual Lipase
-10% digestion
-from salivary glands

Emulsification:
-agitation in stomach
-Bile: Bile salts and Lecithin

Reduces interfacial tension (between fat and water) and allows to break fats down to smaller components for lipase to work on

Pancreatic Lipase increases surface area 1000x and creates a water soluble environment
-->Results in fatty acids and monoglycerides

5

What form are dietary fats mostly in?

Triglycerides

6

Function of Bile Salts

Without bile salts, can't absorb fats

Bile salts form micelles and remove monoglycerides and fatty acids and transport them to the brush border for absorption

Bile salts act as a transport mechanism--once breakdown products, need to remove them for absorption before reforms as fat

7

Chronic Pancreatitis

Calcifications outline pancreas on CT

Causes: Alcohol, genetic, elevated TG, hypercalcemia, obstruction

Complications: Pain, malabsorption of fats, proteins, and carbs, which leads to diabetes

***Stones located at sphincter of Oddi = acute pancreatitis, NOT CHRONIC

8

Steatorrhea

Non-solid feces due to malabsorption of fats

9

Bristol Stool Chart

7 types of poop
Want type 3 or 4
Type 1 and 2 = constipation
Type 5, 6, 7 each diarrhea

10

Emulsificatoin

Micelle's have polar heads that dissolve in water (hydrophilic) and tails that dissolve in fat (hydrophobic)

--this is because we are mostly made of water
--if were mostly fat, micelles would form opposite


Bile salts surround the phospholipids

11

Which of the following is NOT a final breakdown product of carbohydrate digestion?

A. Glucose
B. Galactose
C. Sucrose
D. Fructose

C. Sucrose

Sucrose is broken down to fructose and glucose by sucrase in the intestine

12

Peptidases are important in protein digestions. Where are they located?

A. On villi surface
B. On crypts of Lieberkuhn
C. Within micelles
D. Within pancreatic Duct Epithelium

A. On villi surface

**Brush border of duodenum and jejunum