The Digestive System

Question 1

What are the beliefs of diet and nutrition culture? And how should we look at nutrition and diet culture?

Answer 1

Calories in vs calories out.
Eat less, move more.
Need to appreciate the complexities of our bodies and the environment we live in.

Question 2

What are the factors causing obesity?

Answer 2

Many factors cause obesity, not straightforward.
Involves more than just the individual or calories consumed.
Factors influencing obesity will be different in other countries.

Question 3

What are the functions of the digestive system?

Answer 3

Break down the foods you eat, release their nutrients, and absorb those nutrients into the body.

Question 4

Digestion

Answer 4

the enzymatic breakdown of food to components that can be absorbed into the blood for transport throughout the body.

Question 5

Absorption

Answer 5

The movement of nutrients, salts, and water across the GI tissues into the bloodstream or lympathetic system.
Occurs mainly in small intestine but also a little bit in the large intestine.

Question 6

Digestive tract (gastrointestinal tract or alimentary canal)

Answer 6

Hollow tube from mouth to anus that’s modified along the way to provide different functions

Question 7

What are the components of the alimentary canal?

Answer 7

pharynx, esophagus, stomach, small intestine, large intestine

Question 8

Accessory organs

Answer 8

Aid in digestion, but are outside of the alimentary canal

Question 9

What are the accessory organs that aid in digestion?

Answer 9

Liver, gallbladder, and pancreas

Question 10

What are the processes of digestion?

Answer 10

Propulsion involves swallowing and peristalsis.
Chemical digestion involves enzymes that breakdown food more to allow for absorption.
Mechanical digestion involves chewing, churning, segmentation. First occurs in the mouth, then stomach and sometimes in the large intestine before being expelled.
Absorption involves the nutrients and water move to blood vessels and lymph vessels. Occurs in the small intestine and large intestine.

Question 11

What are the major functions of the stomach?

Answer 11

Storage of ingested food.
Mechanical breakdown of ingested food - chyme.
disruption of chemical bonds in food material by acid and enzymes.
Production of intrinsic factor, a glycoprotein required for absorption of vitamin B12 in the small intestine.

Question 12

What are the three parts of the small intestine?

Answer 12

Duodenum, jejunum, and ileum

Question 13

The Small Intestine

Answer 13

Chyme from the stomach enters the small intestine.
Name is based on diameter and not length; small in diameter and large in length.
Primary digestive organ in the body; where all absorption occurs (90% of water absorption).
Circular folds increases surface area therefore increasing absorption.

Question 14

The Large Intestine

Answer 14

Consists of the cecum, colon, and rectum
Shorter in length but larger in diameter.
No circular folds but some villi.

Question 15

What are the functions of bacteria flora in the large intestine?

Answer 15

Facilitate chemical digestion and absorption.
Synthesize certain vitamins, mainly biotin, pantothenic acid, and vitamin K.
Linked to increased immune response.

Question 16

What are the functions of the large intestine?

Answer 16

Reabsorption of water (last 10%).
Compaction of intestinal contents into feces.
Absorption of important vitamins produced by bacteria.
Storage of fecal material prior to defecation.

Question 17

The Liver

Answer 17

Largest gland in the body.
Has 2 lobes.
All substances leaving the absorptive surfaces of the digestive tract passes through the liver via the hepatic portal vein.

Question 18

What are the functions of the liver?

Answer 18

Metabolic regulation: extract and stores excess nutrients and remove toxins from the blood; releases stored or synthesized fats, proteins, CHO, vitamins, and minerals.
Hematological regulation: synthesizes plasma proteins, removes circulating hormones, antibodies, and damaged red blood cells.
Bile production: breaks up fat droplets improving fat breakdown and absorption.

Question 19

What are the two functions of the pancreas?

Answer 19

Exocrine function: produces pancreatic juice that is released via the pancreatic duct from digestive purposes.
Endocrine function: releases insulin and glucagon into the bloodstream to control blood sugar levels.

Question 20

What is the main function of the gallbladder?

Answer 20

Stores and concentrates bile prior to excretion into small intestine.

Question 21

What is the goal and process of chemical digestion?

Answer 21

Large food molecules must be broken down into subunits that are small enough to be absorbed by the lining of the GI tract.
Chemical digestion occurs from enzymes through hydrolysis (water breaks down a compound).
18 different enzymes are involved in chemical digestion.

Question 22

What is lactose intolerance?

Answer 22

When the body does not have enough lactase enzyme produced by the small intestine (needed to digest milk).
Lactose in the chyme is not digested resulting in it moving into large intestine where the bacteria ferments it and leads to the production of gas, abdominal cramps, bloating, and diarrhea.

Question 23

What occurs in absorption of nutrients in the body?

Answer 23

GI tract processes up to 10L of food, liquids, and GI secretions, but most of this is absorbed in the small intestine.

Question 24

What is the main goal of the mechanical and digestive processes?

Answer 24

Convert food into molecules small enough to be absorbed by the epithelial cells of the intestinal villi of the GI tract.

Question 25

What are the methods of absorption?

Answer 25

Active transport, passive diffusion, facilitated diffusion, co-transport, and endocytosis.

Question 26

Prebiotic

Answer 26

Source of food for your gut’s healthy bacteria.
CHO that your body can’t digest.

Question 27

Probiotics

Answer 27

Live yeasts and good bacteria that live in your body and are good for your digestive system.