Unit 7

Most of the nutrients we consume in food are digested and absorbed

1. 99% of carbs: glucose 2. 92% of proteins: amino acids 3. 95% of fat: fatty acids and glycerol

IBS symptoms are eased by:

1. Avoiding large meals 2. Adding soluble fibers to the diet 3. Using probiotics

Cells use nutrients directly for:

1. Energy 2. Body Structures 3. Regulation of body processes

Diet-related factors and foods that may worsen the symptoms of heartburn

1. Obesity 2. Overeating 3. High-fat foods 4. High-carbohydrate foods 5. Alcohol 6. Spicy foods 7. Tomato sauce 8. Inadequate fiber intake 9. Coffee

Myths about Constipation

1. Poisonous substances are absorbed from stools and cause "autointoxication" diseases. 2. Colon cleansing "detoxifies" the body. 3. Extra-long colons cause constipation. 4. All cases of constipation are cause by inadequate fiber intake. 5. You can treat constipation by drinking plenty of fluids. 6. You can lose weight and stay healthy if you take laxatives regularly. 7. If you do not have a bowel movement everyday there is something wrong with you.

Other Functions of the Gastrointestinal (GI) Tract

1. Regulation of digestion and absorption 2. Prevention of infection and inflammation-related disorders 3. Fiber digestion 4. Vitamin production

How many grams of dietary fiber daily helps prevent constipation?

25-30 grams

Umami (u-mam-e)

A Japanese word meaning "pleasant savory taste." The taste is described as broth or meaty and is recognized as the fifth basic taste. Foods containing glutamate, an amino acid derivative, elicit the umami taste and include fish, meats, mushrooms, ripe tomatoes, and aged cheese.

Heartburn

A condition that results when acidic stomach contents are released into the esophagus, usually causing a burning sensation.

Irritable Bowel Syndrome (IBS)

A disorder of bowel function characterized by chronic or episodic gas; abdominal pain; diarrhea, constipation, or both.

Lymphatic System

A network of vessels that absorb some of the products of digestion and transport them to the heart, where they are mixed with the substances contained in food.

Diagnosis of IBS is made when:

A person experiences symptoms of abdominal pain, bloating, and diarrhea or constipation three times a week for three months or longer.

Digestion of Fat in the large intestine (colon)

A small amount of fatty materials escapes absorption and is carried out of the body with other wastes.

Bile

A yellowish-brown or green fluid produced by the liver, stored in the gallbladder, and secreted into the small intestine. It acts like a detergent, breaking down globs of fat entering the small intestine to droplets, making the fats more accessible to the action of lipase.

How much alcohol is consumed with meals in the stomach?

About 30%

What is associated with duodenal ulcers?

Bacterial (Helicobacter pylori) infection

Digestion of Fat in the small intestine, pancreas, liver, and gallbladder

Bile readies fat for the action of lipase from the pancreas. Lipase splits fats into fatty acids and glycerol that are absorbed.

Lipase

Breaks down fats into fragments of fatty acids and glycerol. Produced in salivary glands (lingual lipase and the pancreas (pancreatic lipase). The action is enhanced by bile.

Amylase

Breaks down starch into smaller chains of glucose molecules. Produced in the salivary glands (salivary amylase) and the pancreas (pancreatic amylase).

Digestion is complete when:

Carbohydrates, fats, and proteins are reduced to substances that can be absorbed; Vitamins and minerals are released from food

Starch

Complex carbohydrates made up of complex chains of glucose molecules. It is the primary store form of carbohydrate in plants. The vast majority of carbohydrate in our diet consists of starch, monosaccharides, and disaccharides.

Gut microbiota

Consume and break down fiber and other undigested food residues. It excretes fatty acids as an end product of fiber digestion. They help fight infection by signaling presence of harmful microbes which are then targeted by body's infection fighting immune system

How can most people with IBS control their symptoms?

Diet, stress management, and medication

Digestion of Carbohydrates (excluding fiber) in the Stomach

Digestion of starch continues while food remains in the stomach. Some alcohol is absorbed here. Acid produced in the stomach aids digestion and destroys many bacteria in food.

Digestion of Fat in the stomach

Fat tends to separate from the watery stomach fluid and foods and float on top of the mixture. About 10-30% of fat is broken down by lingual lipase. Fat is last to leave the stomach.

Digestion of Fat in the mouth

Fat-rich foods are mixed with saliva. Small amounts of lingual lipase accomplish some fat breakdown.

Digestion of Fiber in the Small intestine, pancreas, liver, and gallbladder

Fiber binds cholesterol and some minerals

Ulcers

GI - develop when the protective lining of the stomach or duodenum is the damaged, and the lining is eroded by stomach acid and digestive enzymes.

Digestion of protein in the mouth

In the mouth, chewing crushes and softens protein-rich foods and mixes them with saliva.

How can you relieve heartburn?

Lifestyle changes - losing weight.

Constipation

Medically defined to exist when an individual has fewer than three bowel movement every day

Microbes

Microscopic organisms, including bacteria and fungi. Some microbes are beneficial, some pathogenic (harmful), and some have little effect on the body. Also "microorganisms."

How many medical visits occur each year in the United States for digestive disorders?

More than 104 million.

Digestion of Fiber in the Large intestine (colon)

Most fiber is excreted with feces; some fiber is digested by bacteria in the colon.

Digestion of Fiber in the Stomach

No action

Probiotics

Non-harmful bacteria and some yeasts that help colonize the intestinal tract with beneficial microorganisms and that sometimes replace colonies of harmful microorganisms. The most common probiotic strains are Lactobacilli and Bifidobacteria.

How often does heartburn occur in American adults?

Occurs weekly in about 20% of American adults

Duodenal and Stomach Ulcers

Open sores in the lining of the duodenum (the uppermost part of the small intestine of the stomach).

How is diarrhea treated?

Oral rehydration fluids, and solid foods that are well tolerated.

Digestion of Carbohydrates (excluding fiber) in the Small intestine, pancreas, liver, and gallbladder

Pancreatic amylase continues starch digestion. scurries, lactase, and maltase break down disaccharides into monosaccharides that are absorbed. Some alcohol is absorbed here.

Flatulence

Presence of excess gas in the stomach and intestines.

Enzymes

Protein substances that speed up chemical reactions. They are found throughout the body but are present in particularly large amounts in the digestive system.

Inflammation

Reactions of the body to the presence of infectious agents, toxins, or irritants. Inflammation triggers the release of biologically active substances that promote oxidation and other reactions that counter react the infectious agent, toxin, or irritant.

Maltase

Separates maltose into two molecules of glucose. Produced in the small intestine.

Pepsin

Separates protein into shorter chains of amino acids. Produced by the stomach.

Sucrase

Separates the disaccharide sucrose into the monosaccharides glucose and fructose. Produced in the small intestine.

Monosaccharides (mono=one, sacharide=sugar)

Simple sugars consisting of one sugar molecule. Glucose, fructose, and galactose are examples.

Disaccharides

Simple sugars consisting of two sugar molecules. Sucrose (table sugar) consists of a glucose and a fructose molecule, lactose (milk sugar) consists of glucose and galactose, and maltose (malt sugar) consists of two glucose molecules.

Trypsin

Splits short chains of amino acids into molecules containing, one, two, or three amino acids. Produced by the pancreas.

Lactase

Splits the disaccharide lactose into glucose and galactose. Produced in the small intestine.

Digestion of protein in the stomach

Stomach acid works to uncoil protein stands and to activate the stomach's protein-digesting enzyme. Pepsin breaks the protein strands into smaller chains of amino acids.

Hemorrhoids

Swelling of veins in the anus or rectum.

Circulatory System

The heart, arteries, capillaries, and veins responsible for circulating blood throughout the body.

Digestion of protein in the large intestine (colon)

The large intestine concentrates and carries undigested fiber and other residue out of the body

Digestion

The mechanical and chemical processes whereby ingested food is converted into substances that can be absorbed by the intestinal tract and utilized by the body.

Diarrhea

The presence of three or more liquid stools in a 24-hour period.

Absorption

The processes by which nutrients and other substances are transferred from the digestive system into body fluids for transport throughout the body.

Digestion of Carbohydrates (excluding fiber) in the Mouth

The salivary glands secrete saliva to moisten and lubricate food; chewing crushes and mixes the food with salivary amylase that initiates starch digestion.

Digestion of Fiber in the Mouth

The teeth crush fiber and mix it with saliva to moisten it for swallowing.

Digestion of protein in the small intestine, pancreas, liver, and gallbladder

Trypsin splits proteins into molecules containing one, two, or three amino acids. These amino acids are absorbed.

Soluble Fiber

Types of dietary fiber that dissolves in water, forming a gel. Good sources of soluble fiber include oats, oatmeal, oat bran, apples, bears, dried beans, carrots, and psyllium.

Digestion of Carbohydrates (excluding fiber) in the Large Intestine (colon)

Undigested carbohydrates reach the colon and can be partly broken down by intestinal bacteria.

How is diarrhea prevented?

With water and food sanitation programs, immunizations, and adequate diets