Digestive System

Define metabolism, anabolism, and catabolism.

1. 2. Process of building up complex materials (proteins) from simple materials. 3. When substances are broken down to simpler substances.

How many calories are produced when 1 gram of carbohydrate is oxidized? 1 gram of protein? 1 gram of fat? If you just ate 100 grams of food that was 20 percent protein, 30 percent carbohydrate, and 10 percent fat, how many kilocalories did you consume?

1. 4 calories 2. 4 Calories 3. 9 Calories 4. 290,000 Kilocalories

Match the digestive organ to the function 1. Produces Bile A. Salivary Glands 2. Absorbs Water B. Esophagus 3. Churning Occurs C. Stomach 4. Muscular tube connecting the laryngopharynx with the stomach D. Small Intestine 5. Produces both endocrine and exocrine secretions 6. Secretes a substance that initiates carbohydrate digestion E. Liver 7. Stores Bile F. Gallbladder 8. Segmentation Occurs G. Pancreas H. Large Intestine

1. E 2. H 3. C 4. B 5. G 6. A 7. F 8. D

Define glocogenesis, glycogenolysis, and glycogenesis.

1. Glucose is produced from fats and proteins. 2. Glucose is released from the liver after conversion from glycogen. 3. A process where glucose molecules are converted to glycogen, and glycogen molecules are stored in the liver.

How does the stomach protect itself from being digested?

A protective layer that is composed of mucous cells that produce bicarbonate-rich alkaline mucosa that clings to the stomach walls to protect the stomach.

Which of the following terms are synonyms? A. Gastrointestinal tract B. Digestive System C. Digestive Tract D. Alimentary canal

A. Gastrointestinal tract, C. Digestive Tract, D. Alimentary canal

Hormones that act to decrease blood glucose level include. A. Insulin B. Glucagon C. Epinephrine D. Growth Hormone

A. Insulin

What is the harmful result when excessive amounts of fats are burned to produce ATP? Name two conditions that might lead to this result.

Acidosis: blood becomes acidic. causes: no intake (ie starvation), or extreme over-excertion

Some of the energy released as foods are oxidized is captured to make ATP. What happens to the rest or it?

After the food has been broken down and oxidized to make ATP, what is left over is waste and is eliminated from the body.

The stomach epithelium secretes several substances, including alkaline mucus and intrinic factor. What is the function of each of the two secretions?

Alkaline Mucus protects the stomach wall from being digested. Intrinsic factor is needed for intestinal absorption of vitamin B12.

This bicarbonate-rich (alkaline) juice begins starch digestion in the mouth.

Amalyse

What are the building blocks (and digestion products) of proteins?

Amino Acids

Essential amino acids are

Amino acids our body cannot make and that we must consume in our diet.

The PH of chyme entering the duodenum is adjusted by A. Bile B. Intestinal Juice C. Enzyme secretions from the pancreas D. Bicarbonate-rich secretions from the pancreas

D. Bicarbonate-rich secretions from the pancreas

A 3-year old girl is rewarded with a hug because she is now completely toilet trained. Which muscle is one that she has learned to control? A. Levator Ani B. Internal Anal Sphincter C. Internal and External Obliques D. External Anal Spincter

D. External Anal Spincter

Which of these organs lies in the right hupochondriac region of the abdomen? A. Stomach B. Spleen C. Cecum D. Liver

D. Liver

Where in the stomach do the strongest peristaltic waves occur? A. Body B. Cardiac Region C. Fundus D. Pylorus

D. Pylorus

What substance forms the bulk of the tooth?

Dentin

If you had your choice, would you prefer to have high blood levels of HDLs or LDLs? Explain your answer.

HDLs because they are headed back to the liver for breakdown and elimination from the body.

What is the proper order of the following stages of food processing -- defection, absorption, digestion, ingestion?

Ingestion, digestion, absorption, defecation

This substance is needed for absorption of vitamin B12 from the small intestine.

Intrinsic Factor

How does vasodilation of skin blood vessels affect body temperature on a hot day?

It decreases body temperature.

Why is it important to include cellulose in a healthy diet even though we cannot digest it?

It provides fiber, which is important for moving feces along the colon and dfecation

What modification of the stomach muscularis externa allows it to mechanically digest food?

Its third layer of smooth muscle, the oblique layer, which allows it to knead or pummel the food.

Which condition is the result of the release of bile salts and bile pigments from the liver and into the bloodstream?

Jaundice

Which layer of the alimentary canal surrounds the lumen?

Mucosa

Are oils saturated lipids or unsaturated lipids?

Oils are unsaturated lipids

Which organ contributes to the chemical breakdown of ALL food types?

Pancreas

Why is it necessary for the stomach contents to be so acidic?

Pepsin, the main enzyme of the stomach, needs acidic conditions to work.

How do segmental and peristaltic movement differ?

Peristalsis is involuntary and involves alternating waves of contraction and relaxation of the muscles in the organ wall. Segmentation moves food only back and forth across the internal wall of the organ, serving to mix it with the digestive juices. Thus, segmentation is more an examples of mechanical digestion than of propulsion.

Local collections of the lymphatic system that are found in the submucosa of the small intestine are known as

Peyer's Patches

Which food group is most important for building cell structures?

Proteins

This circular muscle is between the stomach and the small intestine.

Pyloric Sphincter

This protein-digesting enzyme works primarily on milk protein and makes it look lumpy, like cottage cheese.

Rennin

The major absorptive section of the alimentary canal is the

Small Intestine

Mary has a dry mouth -- very little saliva is being secreted. Digestion of which type of food will be affected (decreased) by this situation?

Starch. Saliva contains salivary amylase.

Digestion of proteins begins in the

Stomach

What is the functional value of the microvilli in the absorptive cells of the small intestine?

They tremendously increase the surface area available for absorption of digested foodstuffs.

What happens during the buccal stage of swallowing?

This is the voluntary stage where the tongue pushes the chewed food into the larynx.

What are two means of either maintaining or increasing body temperature?

Vasoconstriction of blood vessels serving the skin and shivering.

What are villi, and why are they important?

Villi are extensions of the mucosa of the small intestine. They increase the surface area of the small intestine tremendously for nutrient absorption.

What are the two main functions of the large intestine?

Water absorption and absorption of some vitamins made by resident bacteria.

What are the major products of the electron transport chain?

Water and ATP

What occurs when your total caloric intake exceeds your TMR?

You gain weight

This is a structural abnormality in which the superior part of the stomach protrudes slightly above the diaphragm.

hiatal hernia

Which is the terminal portion of the small intestine?

ileocecal valve

What is the mescentery? the peritoneum?

the membrane that attaches the intestines to the wall of the abdomen. The peritoneum consists of the parietal and visceral layers + potential space between

What substances are absorbed in the large intestine?

vitamin K and some B vitamins.

Name the subdivision of the large intestine.

Colon Rectum Anal canal Anus

What is the major source of carbohydrates in our diet?

From plants -- fruits, vegetables, and grains

Define defecation reflex, constipation, and diarrhea.

1. Presence of feces in the rectum 2. Abnormally delayed or infrequent passage of dry hardened feces 3. An intestinal disorder characterized by abnormal frequency and fluidity of fecal evacuations.

Describe the two phases of swallowing.

1. The buccal phase: When the food has been chewed and mixed with saliva it forms a bolus. The bolus is forced into the pharynx by the tongue. 2. Pharyngeal-esophogeal phase: after being bolus of food is forced into the pharynx. All passageways except to the stomach. Peristalsis moves the bolus toward the stomach. The cardioesophageal sphincter is opened when food presses against it.

Name three digestive system problems common to middle-aged adults. Name one common to teenagers. Name three common in elderly people.

1. acid reflux, gallstone, diverticulosis 2. irritable bowl syndrome 3. heartburn, diarrhea, constipation

The number of teeth in a full set of baby teeth is

20

What is the normal number of permanent teeth?

32 permanent teeth

What is the composition of feces?

75% water; 5% bacteria; 20% indigestible materials, inorganic matter, and epithelial remains

What dietary changes must be made to prevent brain damage in children with PKU?

A diet low in phenylalanine

A cream cheese and jelly sandwich contains proteins, carbohydrates, and fats. Describe what happens to the sandwich when you eat it relative to events occurring in ingestion, digestion, absorption, and defecation.

As you chew, amylase in the saliva breaks down the starches in the sandwich into glucose. In the stomach, pepsin starts to break down the proteins. As it leaves the stomach into the duodenum, bile salts from the liver and gall bladder help emulsify the fats and lipases from the pancreas break them down to fatty acids. Trypsin and chymotrypsin, also from the pancreas, finish breaking down the proteins.

The material that forms the bulk of a tooth is A. Cement B. Dentin C. Enamel D. Pulp

B. Dentin

Release of secretion leads to A. Contraction of smooth muscle in the doudenal papilla B. Increased secretory activity of liver cells C. Contraction of the gallbladder wall D. Release of bicarbonate-rich fluid by the pancreas

B. Increased secretory activity of liver cells D. Release of bicarbonate-rich fluid by the pancreas

Which events occur shortly after eating? A. Use of amino acids as a major source of energy B. Lipogenesis (and fat deposit) C. Breakdown of fate reserves D. Increased uptake of glucose by skeletal muscles and other body tissues.

B. Lipogenesis (and fat deposit) D. Increased uptake of glucose by skeletal muscles and other body tissues.

A digestive organ that is not part of the alimentary canal is the A. Stomach B. Liver C. Small Intestine D. Large Intestine E. Pharynx

B. Liver

How does cystic fibrosis affect digestion?

Because it clogs the the pancreatic ducts so that pancreatic enzymes cannot reach the small intestine, cystic fibrosis impairs food digestion, and fat digestion is virtually stopped, resulting in fatty stools and an inability to abosorb fat-soluble vitamins.

What is the digestive role of bile? What organ secretes bile?

Bile, secreted by the liver, acts as a detergent to mechanically break up large fat masses into smaller ones for enzymatic digestion.

Complete this statement. In glycolsis_____is oxidized, and______is reduced. A. Vitamin-containing coenzyme; glucose B. ATP; ADP C. Glucose; Oxygen D. Glucose; Vitamin-containing coenzyme

C. Glucose; Oxygen

The GI tube tissue layer responsible for the actions of segmentation and peristalsis is the A. Serosa B. Mucosa C. Muscularis Externa D. Submucosa

C. Muscularis Externa

What is the role of CCK in digestion?

CCK causes the pancreas to secrete enzyme-rich fluid and stimulates the gallbladder to contract and the duodenal papilla to open

What are the major end products of the Krebs cycle?

Carbon dioxide and reduced coenzyes

What name is given to the process in which glucose is combined with oxygen to yield CO2, H2O, and ATP?

Cellular respiration

Name the subdivisions of the small intestine in a proximal to distal direction. Do the same for the subdivision of the large intestine.

Duodenum Jejunum Ileum

Bile emulsifies fat. Define emulsify.

Emulsify means to physically break large fat globules into smaller ones, providing more surface area for the fat-digesting enzymes to work on

What substance covers the tooth crown? What substance makes up the bulk of the tooth? What is pulp, and where is it?

Enamel covers the tooth crown. Dentin makes up the bulk of the tooth. Pulp is the area of the tooth that contains the blood vessels and nerve endings for the tooth. Pulp is found in the center of the tooth.

What are brush border enzymes?

Enzymes located on the micovilli of intestinal absorptive cells

Other than ATP production, list two uses of fats in the body.

Fats are used in synthesis of myelin sheaths and of cellular membranes, and as body insulation.

What does it mean when we say the food went down the wrong tube?

Food went down the air passage way (trachea) instead of the digestive passageway (esophagus)

Which of the following would you expect to yield a relatively high BMR: old age, large surface area relative to volume, female sex, deficient thyroxine production?

Large surface area relative to volume

Which organ creates bile?

Liver

What is the gluconeogensis?

Making Glucose from noncarbohydrate molecules, e.g., fats and proteins.

How do mechanical break down and digestions differ from each other?

Mechanical breakdown physically breaks down food by squeezing and pummeling it. Digestion breaks down food chemically by destroying chemical bonds.

What is the most significant role that vitamin play in the body?

Most are coenzymes to bring about metabolic reactions

What is the sequential order (mouth to anus) of the digestive organs making up the alimentary canal?

Mouth, Pharynx, Esophagus, Stomach, Small Intestine, Large Intestine, Anus

What happens to the ammonia released when amino acids are "burned" for energy?

The liver combines ammonia with carbon dioxide to form urea. Urea is the eliminated from the body in urine.

How does segmentation differ from peristalisis in terms of moving substances along the GI tract?

The main goal of segmentation is to mix the food thoroughly, through some propulsion occurs. Peristalsis is a propulsive activity.

What is the protective value of having several sets of tonsils at the oral entrance to the pharynx?

The mouth is a favored site of entry for bacteria, and the presence of the tonsils is very effective at preventing many pathogens from getting further into the digestive system.

Only one organ produces enzymes capable of digesting all groups of food. Which organ is this?

The pancreas

Which muscular sphincter regulates the flow of chyme into the small intestine?

The pyloric sphincter

In which organ of the alimentary canal does protein digestion begin?

The stomach

Assume you have been chewing a piece of bread for five or six minutes. How would you expect its taste to change during this time? Why?

a.)The salivary amylase in your mouth would begin digesting the starch in the bread and breaking it down into maltose, so it would have a sweeter taste. b.)The starch in the bread mixes with the enzyme secreted in the mouth that starts digesting starch and convert it to sugar. So, the bread will taste sweeter.

Which anatomical structure prevents the backflow of acid into the esophagus?

cardioesophageal sphincter

This extension of the peritoneum covers the abdominal organs and contains fat and lymphoid follicles.

greater omentum

Name two regions of the digestive tract where mechanical food breakdown occurs, and explain how it is accomplished in those regions.

mixing of food in the mouth by the teeth and tongue and churning, segmentation by the small intestine

Name the layers of the alimentary tube wall from the lumen outward.

mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

Name three pairs of salivary glands.

parotid glands, submandibular glands, and sublingual glands

What is the function of Gastrin?

stimulate acid secretion by stomach and intestinal motility.