Digestive Questions

What would happen if the villi become damaged?

If the villi were damaged, the small intestine would not have enough surface area to absorb nutrients. Therefore, the body would not get all of the nutrients it needs, causing one to get sick.

What happens when either of these functions does not work correctly?

If the water is not removed from the undigested material, the body will produce diarrhea as you will be dehydrated and not getting the water you need. If too much water is absorbed then your body will be constipated. If the body does not create waste, then, all the food will be stored in your body in the large intestine. Bacteria will feed on undigested food particles, and produce hydrogen, methane, and carbon dioxide.

What is chyme?

Chyme- partially digested food and digestive secretions that are formed in the stomach and intestine during digestion

What is in pancreatic juice?

Pancreatic juice is a liquid secreted by the pancreas, which contains a variety of enzymes, including trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase, nucleases and amylase. This acid is another important part of the digestive system and helps for proper digestion.

Which enzymes are present in the small intestine and secreted from the small intestine?

Peptidase- Breaks down dipeptides into amino acids Maltase, lactase, sucrase - Breaks down remaining disaccharides into monosaccharides : All of these are present and secreted

Explain peristalsis.

Peristalsis- the process by which the muscles in the esophagus contract and relax, squeezing food into the stomach.

Why and when would you take TUMS? What do they do?

You would take TUMS in order to relieve stomach pain. TUMS works by neutralizing the stomach acid that is causing the pain and lowering the stomach's pH.

Ulcer

a "hole" or sore on the stomach wall. It can form when acids or enzymes damage the stomach's lining because there is no mucus to protect it and the acids are against the lining.

Sucrase

breaks down sucrose, which is found in sugar, into two smaller elements.

Jejunum

middle segment of the small intestine and it helps to absorb the bulk of the nutrients

What happens in the small intestine?

Chemical digestion begins when food is broken down in the duodenum. Then, the food enters the middle section of the small intestine, jejunum, which absorbs the majority of the nutrients from the chyme. The digested food passes through the capillaries and lymphatic vessels in the wall in the intestine. Nutrients like glucose and amino acids are absorbed into the capillaries while fats are absorbed into the lymph vessels.

Describe the process of digestion in the mouth.

First, mechanical digestion occurs when the food is chewed by teeth. Next, salivary glands secrete saliva and make the food easier to chew. Lastly, chemical digestion occurs when the salivary enzymes break down the food further.

What is in gastric juice?

Gastric Juice- an acidic fluid in the stomach that assists in chemical digestion. It is composed of hydrochloric acid, pepsin, mucus.

Small Intestine pH

basic

Lipase

breaks down fats into smaller molecules of glycerol and fatty acid

Erepsin

breaks down large polypeptide proteins into smaller amino acid molecules.

Maltase

breaks down maltose, a carbohydrate, and turns it into glucose which is later absorbed by the body.

Starches

digested in the mouth

Lactase

digests lactose, a major component of dairy. It can diminish in quantity when one is aging. The deficiency of lactase causes abdominal stomach problems.

Amylase

pancreatic or saliva; breaks the chemical bonds between sugar monomers and starches

Stomach pH

1.5 to 3.5.

Mouth pH

5.5 to 7.5

What is the function of bile? Where does it come from?

Bile is a liquid in the small intestine that helps digest lipids and allows the body to excrete waste products from the blood. Bile, unlike many other digestive acids, does not contain enzymes. Instead, it contains bile salts which allow for the breakdown of fats. Bile is produced by the liver cells and enters the small intestine.

What food gets digested in the mouth?

Enzymes in the saliva digest starches and fats.

What is the function of peristalsis in the small intestine?

Food is propelled through the small intestine by peristalsis, a sequence of muscle contractions. During peristalsis, the longitudinal muscles in the small intestine's wall contract, and then the circular muscles contract, allowing the food to move forward. Peristalsis, along with enterogastric reflex and segmentation, regulate the amount of food in each area of the small intestine, allowing for the maximum amount of absorption.

Define ingestion, absorption and elimination.

Ingestion- the process of consuming or taking in a substance, usually through the mouth. Absorption- the process of absorbing nutrients from a substance into cells or tissues. Elimination- the process of removing the undigested food and waste from a substance.

What is the function of intestinal juice?

Intestinal juice helps completing protein digestion.

What is the difference between intracellular and extracellular?

Intracellular- when digestion takes place inside the cells. This usually occurs in simpler organisms. Extracellular- when digestion takes place outside the cells, usually in the digestive tract. Food is broken down by acid, and this usually occurs in more complex organisms.

There are three main functions of the large intestine, what are they?

It removes water from undigested material It creates and holds useless material, or waste, from digestion It houses bacteria that digests the food further by feeding on materials in the small intestine (vitamin K)

What is the difference between mechanical and chemical digestion?

Mechanical Digestion- the process of physically tearing and crushing food to digest, usually by the mouth. An example is chewing. Chemical Digestion- the process by which enzymes break down food into smaller molecules. An example is in the saliva or in the stomach.

What type of digestion occurs in the esophagus?

No digestion occurs here

Why don't cells just produce pepsin?

Pepsin breaks down proteins and our cells are made of proteins. If pepsin were produced by our cells, the pepsin would just destroy the cells it was being produced by. Although our stomachs are proteins, our stomachs are lined with mucus which protects it from the pepsin.

What gets digested in the stomach? and how?

Proteins are digested in the stomach. The enzyme pepsin breaks down proteins in the stomach. The pepsinogen that is created by the chief cells in inactive until it comes in contact with the hydrochloric acid. It then turns into pepsin and breaks down the proteins.

What is the role of saliva?

Saliva allows consumed foods to pass through to the digestive system. It also contains enzymes that help break down food in chemical digestion.

What is the pH of the stomach, and how does this affect the enzymes that end up here?

The PH is 1.5 to 3.5. These enzymes function the best and are meant to survive in the low PH of the stomach.

What are the three parts to the small intestine and what are their functions?

The duodenum, jejunum and the ileum are the three parts of the small intestine. Duodenum- the first part of the small intestine. It takes in the chyme and helps to digest it. Jejunum- is the middle segment of the small intestine. It helps to absorb the bulk of the nutrients before being passed on to the ileum. ileum- the last part of the the small intestine. Here, the remaining nutrients are absorbed in order to go into the large intestine.

How does the gallbladder aid in digestion?

The gallbladder is a small, pouchlike organ that stores bile that is from the liver

How does the small intestine increase absorption? Describe these structures. How do fats get absorbed?

The small intestine has many adaptations to increase absorption. The small intestine is over 20 feet long, allowing for a lot of surface area for absorption. Small, finger-like structures called villi protrude from the small intestine's lining and increase nutrient absorption. On each villus there are microvilli, microscopic hairs, which are sometimes referred to as a "brush border" because they look like bristles of a paintbrush. These microvilli also help to increase the amount of nutrient absorption in the small intestine. Fats are too large to be absorbed through the capillaries in the villi. Instead, the lacteals, or the thick lymphatic vessels, absorb the fats.

Gastric Juice

an acidic fluid in the stomach that assists in chemical digestion. It is composed of hydrochloric acid, pepsin, mucus.

Intestinal juice

contains hormones, digestive enzymes, mucus, substances to neutralize hydrochloric acid coming from the stomach which further digests polypeptides into amino acids, completing protein digestion.

Duodenum

first part of the small intestine and it takes in the chyme and helps to digest it

Ileum

last part of the the small intestine where the remaining nutrients are absorbed

Bile

liquid in the small intestine that helps digest lipids and allows the body to excrete waste products from the blood

Pancreatic juice

liquid secreted by the pancreas, which contains a variety of enzymes, including trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase, nucleases and amylase.

Chyme

partially digested food and digestive secretions that are formed in the stomach and intestine during digestion

Villi

protrude from the small intestine's lining and increase nutrient absorption

Chief Cells

release pepsinogen which is converted into the enzyme pepsin by the gastric acid.

Parietal Cells

secrete hydrochloric acid.

Mucous Cells

secrete mucous to protect the stomach from its own digestive secretions.

Peristalsis

the process by which the muscles in the esophagus contract and relax, squeezing food into the stomach

Intracellular

when digestion takes place inside the cells. This usually occurs in simpler organisms. Most organisms that use intracellular digestion belong to Kingdom Protista, such as amoeba and paramecium. Amoeba uses pseudopodia to capture food for nutrition in a process called phagocytosis.

Extracellular

when digestion takes place outside the cells, usually in the digestive tract. Food is broken down by acid, and this usually occurs in more complex organisms.

Acid reflux

when stomach acid raises higher than the stomach and irritates the food pipe lining.

What is acid reflux? What are the causes?

Acid reflux- when stomach acid raises higher than the stomach and irritates the food pipe lining. It is caused when the cardiac sphincter, which prevents things from coming up the esophagus, doesn't work, which allows the acid to come up the esophagus.

Which enzymes are present in the small intestine yet come from accessory organs?

Amylase - Continues the breakdown of starch from the pancreas Trypsin - Continues the breakdown of protein from the pancreas Lipase - Breaks down fat from the pancreas

What are autotrophs and heterotrophs?

Autotrophs- able to produce nutrition from simple organic substances. Heterotrophs- rely on the consumption of autotrophs to get their nutrition.

What enzyme is present in the mouth and where does it come from? What does it do?

Salivary amylase is the enzyme present in the mouth. It comes from the salivary glands in the mouth. The salivary amylase breaks the chemical bonds between sugar monomers and starches, making the food easier to chew and swallow.

What is the environment of the stomach like? Why is it that way?

The environment of the stomach is very acidic because of the hydrochloric acid.

What is the role of the epiglottis?

The epiglottis is the part of the throat that covers the windpipe during the swallowing of food in order to protect the windpipe.

What cells line the stomach? What is their function?

The lining of the stomach has million of gastric glands that produce mucus and hydrochloric acid. There are three main cell types that line the stomach. Mucous Cells- secrete mucous to protect the stomach from its own digestive secretions. Chief Cells- release pepsinogen which is converted into the enzyme pepsin by the gastric acid. Parietal Cells- secrete hydrochloric acid.

Describe the process of digestion in the stomach.

The lining of the stomach has millions of gastric glands that produce mucus and hydrochloric acid. The acid secreted by the gastric glands activates pepsin, an enzyme, which begins the process of protein digestion, breaking proteins into smaller polypeptide fragments.

What is the role of liver in digestion?

The liver is a large organ just above the stomach. The liver produces bile which dissolves lipids. This makes it possible for enzymes to reach the fat molecules and break them down. It also processes the nutrients absorbed in the small intestine

What is the role of the pancreas in digestion? List all the substances it produces and their functions.

The pancreas produces enzymes that break down food further and hormones. The pancreas is not involved in digestion. a) Digestive enzymes including lipase break down food b) Insulin to lower glucose levels c) Glucagon releases energy to raise glucose levels d) Pancreatic polypeptide and somatostatin regulate cells that produce insulin and glucagon

What is the pH of the small intestine and what makes it this pH? How does the pH affect enzymes from the stomach and from accessory organs?

The small intestine needs to have a basic environment to work well. The pH of the small intestine ranges from 8 to 10. After food comes from the stomach it is acidic. In order to neutralize the acid the small intestine uses bile. Sodium bicarbonate which is created in the pancreas then goes to the small intestine which turns keeps the liquid basic. Pepsin works in a pH of 1 to 3, and it has to be shut off by the basic environment of the small intestine.

What is an ulcer? How do you get one?

Ulcer- a "hole" or sore on the stomach wall caused by bacteria removing mucus off the stomach lining and not protecting it. It can also form when acids or enzymes damage the stomach's lining because there is no mucus to protect it and the acids are against the lining.

What is the pH of the mouth?

Usually, a healthy pH in the mouth is between 5.5 and 7.5.

Why are the liver and gallbladder connected? Can I survive with either one of these organs?

Without the liver, the body would not be able to produce the bile that is necessary to dissolve fats. Without the gallbladder, there would be no where to keep the bile and it would therefore be useless.

Can you swallow upside down?

Yes, the smooth muscles in the esophagus will push the food down independent of gravity. Through contractions of the muscles in the esophagus, this is called peristalsis.