Digestion and Absorption

Question 1

What/where are Chief cells?

Answer 1

Found in the stomach
Release lipase
Release pepsinogen (precursor to pepsin)

Question 2

What/where are parietal cells?

Answer 2

Found in stomach
Release intrinsic factor (for B12 absorption)
Release HCL

Question 3

Functions of HCL

Answer 3

Denatures proteins
Kills pathogens on foods
Activates pepsinogen to pepsin (breaks down proteins)
Activates intrinsic factor

Question 4

What/where are mucus cells

Answer 4

Release mucus from stomach lining to protect it from HCL

Question 5

Microvilli

Answer 5

Line the small intestine
Protect the lining of the small intestine
Help w/ nutrient absorption by containing enzymes sucrase, maltase, and lactase

Question 6

Sections of the small intestine

Answer 6

Duodenum - food continues to break down
Jejunum - major site of nutrient absorption
Ileum - major site of nutrient absorption

Question 7

Common bile duct

Answer 7

Carries bile from the liver and gallbladder through the pancreas to the small intestine

Question 8

Cholecystokinin (CCK)

Answer 8

A hormone stimulated by the entrance of fat and protein into the duodenum
CCK then stimulates the release of bile from the gallbladder

Question 9

Bile

Answer 9

Created in the liver and stored in the gallbladder
In the duodenum bile (containing bile salts) mixes with pancreatic enzymes to speed up digestion and absorption
Helps remove bilirubin produced when the body breaksdown old blood cells
Converts some cholesterol to bile acids which are removed through feces

Question 10

Enterokinase

Answer 10

Inactive enzymes from pancreas are called zymogens
Enterokinase is a proteolytic enzyme released from the duodenum and activates trypsinogen to trypsin
Reduced w/ SNP and w/ significant microvilli damage (e.g. Crohn’s, Celiac, food allergies or sensitivities, immune-compromised)
Supplemental digestive enzymes can help w/ digestion

Question 11

Trypsin

Answer 11

Activates other zymogens into digestive enzymes

Question 12

Ectoenzymes

Answer 12

Oligosaccharides, monosaccharides, and peptidases located in the microvillil
Responsible for final breakdown of carbs (fructose, glucose) and proteins (amino acids)

Question 13

Bile Salts

Answer 13

Bile salts combined w/ lipase break down fats into free fatty acids which makes them “water-soluble” so they can be absorbed into the lymphatic fluid
Bile salts contain:
Colic acid
Chenodeoxycholic acid
Taurine
Glycine
Cholesterol
Electrolytes
water

Question 14

Pancreatic lypase

Answer 14

Breaks fats into free fatty acids and monoglycerides w/ help from bile salts that initiate the process

Question 15

Function/ Sections of the large intestine

Answer 15

Reabsorbs water and ferments starches
Ascending colon
Transverse colon
Descending colon

Question 16

Fermented starches

Answer 16

During fermentation, prebiotics are converted to butyrate w/ adequate fiber intake
- Feed colonocytes and good bacteria
- Help heal the digestive lining
- Boost the immune system
- Keep cholesterol levels healthy

Question 17

Soluble fiber

Answer 17

Water-soluble
Attacts water
Reduces cholesterol
Beans, oats, Beta-glucans (yeast, bacteria, fungi), gums, pectins, fruits, veggies
Need 25-35/g of soluble fiber daily
Over 50g/d can prevent fat absorption and inhibit non-fiber absorption increasing sugar and starch levels in the colon

Question 18

Insoluble fiber

Answer 18

Not water soluble
whole grains, veggies,
Cellulose
Lignans

Question 19

Non-fermentable fiber

Answer 19

Make up the mass of the stool
e.g. psyllium

Question 20

Absorption - Passive/simple diffusion

Answer 20

Nutrients move from a high concentration area to a low concentration area
- used for fats (e.g. peanut butter)

Question 21

Absorption - Facilitated Diffusion

Answer 21

Nutrients move from a high concentration area to a low concentration area ATTACHED TO A LIPID-SOLUBLE PROTEIN CARRIER
- used for carbohydrates

Question 22

Absorption - Active transport

Answer 22

Moves against the concentration gradient
- used for proteins and ions

Question 23

Enterocytes

Answer 23

Epithelial cells lining the intestinal wall and contain microvilli
Create tight junctions that allow nutrients to be absorbed but prevent waste and pathogens

Question 24

What is needed to prevent leaky gut?

Answer 24

• healthy microbiota
• secretory IgA (first line of defense)
• peristaltic movement
• filtration by enterocytes
• healthy mucosal lining
  *** glutathione and glutamine

Question 25

Secretory IgA

Answer 25

Released by gut-associated lymphatic tissue (GALT)

Question 26

Tight junctions can be compromised by

Answer 26

• consuming allergic or sensitive foods that activate the immune system
• high stress that takes glutamine away from the small intestine
• e. coli
• development of h. pylori
• low bacterial diversity
• continual use of antibiotics

Question 27

Glutathione

Answer 27

Primary body antioxidant in high concentrations in the stomach and duodenum
- important for proper intestinal barrier function
- made from l-glutamine, cysteine, glycine

Question 28

L-glutamine

Answer 28

Primary fuel source for enterocytes
Great for healing intestinal permeability
Supports the microvilli
Part of glutathione synthesis
Shuttled to immune system away from digestion during times of stress, infection, or injury

Question 29

Microvilli

Answer 29

Brush border on enterocytes
- nutrient absorption
- decreased pathogen activity
- healthy tight junctions

Question 30

Short Chain Fatty Acids (SCFAs)

Answer 30

Created by the fermentation of fiber
- provide intestinal integrity and immune health
- supply energy to enterocytes
- act as anti-inflammatory agents
- participate in glucose homeostasis
- help regulate obesity and gene expression