Unit 4, Chapter 10: The Digestive System Flashcards

Question

What is the function of vitamin E in the body?

Answer 1

- Strengthening red blood cell membranes

Answer 2

Dairy products

Answer 3

Dark, leafy greens

Answer 4

- Transporting dissolved nutrients into the cells that line the small intestine - Flushing toxins from cells - Lubricating tissues and joints - Forming essential body fluids, such as blood and mucus - Regulating body temperature (by sweating) - Eliminating waste materials (in urine and sweat) Water is vital for maintaining the body's fluid balance, the condition in which the amount of fluid lost from the body equals the amount of fluid taken in. A constant supply of water is needed to replenish the fluid lost to normal, daily bodily functions. An average adult produces 1.5 Litres of urine per day and loses about 1 litre of water through breath, perspiration, urine, and bowel movements.

Answer 5

Filter feeders are aquatic animals that use a body structure similar to a filter basket to gather organisms, such as protists, bacteria, and the larvae of many aquatic animals, suspended in the surrounding water. The Filter feeder siphons water into is mouth and then filters it to obtain small organisms to digest. The tube sponge is a filter feeder.

Answer 6

Substrate feeders live in or on their food source and eat their way through it. Caterpillars and earthworms are substrate feeders.

Answer 7

Fluid feeders obtain food by sucking or licking nutrient-rich fluids from live plants or animals. Fluid feeders have mouth parts that are adapted to pierce or rip skin or leaf tissue. The same or other mouth parts are used to suck or lick the blood or sap that is their food. Mosquitos are fluid feeders.

Answer 8

Bulk feeders include many animals and most vertebrates. Bulk feeders ingest fairly large pieces of food and some, like the great blue heron, swallow their food whole. Other bulk feeders use tentacles, pincers, claws, fangs, or jaws and teeth to kill prey, to tear off pieces of meat or vegetation, or to take in mouthfuls of animal or plant food.

Answer 9

The essential function of the digestive system is to breakdown food into small, soluble units that can pass through cell membranes. The digestive system breaks down food into useful substances that can be absorbed into the circulatory system. The circulatory system transports these substances to the individual cells of the body.

Answer 10

The four stages of food processing in animals are ingestion, digestion (mechanical and chemical), absorption, and elimination.

Answer 11

Ingestion is the taking in or eating of food. Stage 1.

Answer 12

Absorption is the transport of the products of digestion from the digestive system into the circulatory system, which distributes them to the rest of the body. Stage 3.

Answer 13

Digestion is the breakdown of food by mechanical and chemical processes into molecules small enough for cells of the body to absorb. Stage 2.

Answer 14

Elimination is the removal of undigested solid waste matter from the body. Stage 4.

Answer 15

The tube through which food is processed, beginning at the mouth and ending at the anus; also known as the digestive tract

Answer 16

The physical breakdown of large pieces of food into smaller pieces in the mouth by the action of teeth, beak, or other similar structures, and by contractions and churning motions in the stomach

Answer 17

The chemical breakdown of nutrient molecules into smaller molecules by enzyme action

Answer 18

The chemical breakdown of nutrient molecules into smaller molecules by enzyme action

Answer 19

Herbivores and omnivores usually have longer digestive tracts, relative to their body size, than carnivores. Because the cellulose walls in plant tissue are more difficult to digest than animal tissues, most herbivores have relatively longer digestive tracts, which allows the extra time needed for digestion.

Answer 20

Always contain carbon, hydrogen and oxygen--always in the same proportion: two atoms of hydrogen and one atom of oxygen for every atom of carbon.

Answer 21

Macromolecules are often grouped into four major categories: carbohydrates, lipids (such as fats), proteins, and nucleic acids. Energy released from these macromolecules, and matter supplied by them, is used to maintain the body's metabolism.

Answer 22

- Provide materials to build cell membranes | - Provide quick energy for use by cells

Answer 23

Basic structure of lipids is a molecule of glycerol (an alcohol) consisting of three carbon atoms, each attached to a fatty acid chain (an acid with a long tail of carbon and hydrogen atoms).

Answer 24

- Store energy reserves for later use by cells - Cushion and insulate internal organs - Provide materials to build cell membranes

Answer 25

Phospholipids are lipids that form the membrane that separates a cell from its external environment

Answer 26

Most protein molecules are made up of hundreds of amino acids joined together by peptide bonds into one or more chains.

Answer 27

- Provide structure and support for blood cells, body tissues, and muscles - Aid in muscle movements, such as contraction - Act as catalyst to speed up chemical reactions in the cells - Provide immunity against infections and disease - Transport ions in cell membranes

Answer 28

- Contain the organisms' genetic information | - Direct the organism's growth

Answer 29

Glucose, fructose, lactose, maltose, starch, glycogen, cellulose

Answer 30

fats, oils, waxes

Answer 31

Insulin, hemoglobin, collagen, antibodies, enzymes

Answer 32

The two types of nucleic acids are ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

Answer 33

During hydrolysis, a water molecule is added to the macromolecule (the carbohydrate, protein, or lipid); this breaks the chemical bonds that hold together the smaller molecules from which the macromolecule is made. After hydrolysis, the smaller molecules can be absorbed by cells lining the small intestine.

Answer 34

Digestive enzymes help speed up the process of hydrolysis. Enzymes act as catalysts, which are substances that increase the rate of chemical reactions without being used up in the reactions. Enzymes are secreted by cells in the digestive tract.

Answer 35

Type of Enzyme: Carbohydrase Macromolecule it breaks down: Carbohydrate Product of breakdown: Simple sugars Example of Enzyme and where it functions: Amylase - produced in the salivary glands and functions in the mouth

Answer 36

Type of Enzyme: Lipase Macromolecule it breaks down: Lipid Product of breakdown: Glycerol (an alcohol) and fatty acids Example of Enzyme and where it functions: Pancreatic lipase - produced in the pancreas and functions in the small intestine

Answer 37

Type of Enzyme: Protease Macromolecule it breaks down: Protein Product of breakdown: Amino acids Example of Enzyme and where it functions: Pepsin - produced by stomach glands and functions in the stomach

Answer 38

Type of Enzyme: Nuclease Macromolecule it breaks down: Nucleic acid Product of breakdown: Nucleotides Example of Enzyme and where it functions: Pancreatic nuclease - produced in the pancreas and functions in the small intestine

Answer 39

Carbohydrates serve as short-term or long-term energy storage in the body.

Answer 40

Monosaccharides are single-unit sugars, such as glucose. Disaccharides are formed by a bond between two monosaccharides; an example of a disaccharides is sucrose.

Answer 41

Macromolecules are broken down into smaller molecules by digestive enzymes, which speed up the process of hydrolysis.

Answer 42

Carbohydrates

Answer 43

- Provide structure and support for blood cells, body tissues, and muscles - Aid in muscle movements, such as contraction - Act as catalyst to speed up chemical reactions in the cells - Provide immunity against infections and disease - Transport ions in cell membranes - Enable cells to respond to chemical stimuli

Answer 44

Glands in the mouth that produce saliva to begin the chemical digestion of food

Answer 45

A watery secretion in the mouth that begins the digestive process

Answer 46

Chemical digestion begins with saliva. Saliva contains an enzyme called amylase that starts to break down the starches in food into simpler sugars. Saliva dissolves water-soluble food particles. It stimulates the taste buds, making it possible to taste the flavours of the food. It also lubricates the food to make it easier to swallow. Mechanical digestion also begins in the mouth as your teeth bite, tear, and grind food into smaller pieces. This mechanical action also exposes more of the surface area of the food to the saliva, making it more accessible for chemical digestion.

Answer 47

The muscular tube through which food passes from the mouth to the stomach

Answer 48

A wave-like series of muscular contractions in the esophagus

Answer 49

As you chew your food, your tongue helps mould and smooth it into a soft mass, called a bolus, that the tongue then pushes to the back of your mouth. When you swallow, the bolus enters the top of the esophagus to begin its passage to your stomach. To prevent food from going down the wrong tube and choking you when you swallow, the opening of the trachea is closed by a valve called the epiglottis when you swallow.

Answer 50

The esophagus is a hollow muscular tube that transports each bolus of food to the stomach in a series of wave-like muscular contractions called peristalsis. Glands in the lining of he esophagus produce mucus, which keeps the passage moist and aids in swallowing. The entrance to the stomach is controlled by a ring of muscle called the esophageal sphincter. This sphincter is normally closed to prevent the acid contents of the stomach from backing up into the esophagus, but it relaxes to allow each bolus of food to enter the stomach.

Answer 51

The stomach is a muscular, J-shaped organ in which food is temporarily stored while further chemical and mechanical digestion takes place. This organ lies on the left side of the abdominal cavity, just below the diaphragm, which is the sheet of muscle that separates the heart, lungs, and ribs from the abdominal cavity. The walls of the stomach are folded like an accordion, allowing the stomach to expand and contract as it fills with food and then empties its contents into the small intestine. The stomach is lined with millions of gastric glands that secrete gastric juice when stimulated by the presence of food. The mucus coats the walls of the stomach, protecting it from attack by the strongly acidic gastric juice. The rest of the gastric juice continues the chemical digestion of food.

Answer 52

A mixture of hydrochloric acid, salts, enzymes, water, and mucus that is produced by glands in the stomach to help digest food.

Answer 53

The stomach has three layers of muscle fibres that contract and then relax to churn and mechanically break up pieces of food and mix them with the gastric juice. The result of this churning and mixing is a thick liquid called chyme. At the lower end of the stomach is a muscular valve called the pyloric sphincter. When closed, this valve keeps food in the stomach.

Answer 54

A thick liquid produced in the stomach and made of digested food combined with gastric juice

Answer 55

An enzyme in gastric juice that helps break down proteins into polypeptides

Answer 56

The stomach usually does not digest the proteins that make up its own cells, because it has three methods of protection. First, the stomach secretes little gastric juice until food is present. Second, some stomach cells secrete mucus, which prevents gastric juice from harming the cells of the stomach lining. Third, the stomach produces its protein-digesting enzyme, pepsin, in a form that remains inactive until hydrochloric acid is present. Once active, pepsin hydrolyzes proteins to yield polypeptides -- a first step in protein digestion in the digestive tract.

Answer 57

The network of nerves surrounding the stomach initiate contractions that release partially digested food into the small intestine. When the small intestine is full and still digesting food, the stomach temporarily stores the chyme. When processed food has moved out of the small intestine into the large intestine, the pyloric sphincter opens and the stomach pushes chyme into the first part of the small intestine -- the duodenum.

Answer 58

The small intestine is the part of the alimentary canal in which digestion is completed--that is, the nutrient macromolecules are finally broken down into their component molecules. The nutrients are then absorbed through the membranes of the cells that line the small intestine, and they pass rom the digestive system into the circulatory system. The circulatory system carries the nutrients to cells and tissues throughout the rest of the body.

Answer 59

A short, wide U-shaped section of the small intestine into which food passes from the stomach

Answer 60

Finger-like projections lining the surface of the small intestine that increase the surface area to improve the absorption of nutrients

Answer 61

The small intestine looks like a long, folded tube divided into three main regions. The first region after the stomach is the U-shaped duodenum. To speed up the process of absorption, the walls of the small intestine are lined by folds that greatly increase the surface area through which nutrients can be absorbed. The folds are covered by tiny, finger-like projections called villi. Each villus, in turn, is covered with many fine brush-like microvilli. As food passes through the duodenum, it receives secretions from two organs that support the functions of the digestive system: the pancreas and gall bladder.

Answer 62

The portion of the small intestine that follows immediately after the duodenum

Answer 63

The portion of the small intestine that follows immediately after the jejunum

Answer 64

A greenish-yellow fluid secreted by the liver that helps digest fat

Answer 65

Following the duodenum is a structure called the jejunum, which is about 2.5 m long and contains more folds than the duodenum. The jejunum breaks down the remaining proteins and carbohydrates so the end products can be absorbed into the bloodstream.

Answer 66

The ileum, which is about 3 m long, contains fewer and smaller villi that either the duodenum or the jejunum. Its function is also to absorb nutrients, as well as to push the remaining undigested material into the large intestine.

Answer 67

The pancreas and gall bladder are not part of the alimentary canal itself, but they are connected to the canal by ducts. Because of this close association with the alimentary canal, the pancreas and gall bladder are referred to as accessory organs. Fluids produced by the accessory organs are essential to the process of digestion.

Answer 68

In an adult human, the pancreas secretes about 1 L of pancreatic fluid into the duodenum each day. Pancreatic fluid contains numerous enzymes that chemically digest carbohydrates, lipids, and proteins. The fluid also contains bicarbonate, which is very important to the function of enzymes. The bicarbonate alters the pH of chyme from strongly acidic to weakly basic, thereby producing conditions in which enzymes in the pancreatic fluid can work most efficiently.

Answer 69

The liver is the largest internal organ in the human body. In and adult, it is the size of a football, with a mass of about 1.5 kg. The main digestion-related secretion of the liver is bile, a greenish-yellow fluid mixture that is made up of bile pigments and bile salts. Bile pigments do not take art in digestion. They are waste products from the liver's destruction of old red blood cells, and they are eventually eliminated with feces.

Answer 70

After bile is produced in the liver, it is sent to the gall bladder, which stores the bile between meals. Bile contains bile salts that are essential for the digestion of fats. Because fats are insoluble in water, they are suspended in chyme as small droplets. Bile salts physically break up the fat droplets into smaller fat droplets, and suspending the smaller fat droplets so they can disperse throughout the chyme. The many smaller fat droplets create a greater surface area to be exposed for digestive enzymes to chemically break down the fats in the small intestine: this makes it easier for the intestinal cells to absorb the fats.

Answer 71

The bile and pancreatic fluid in the duodenum help break down carbohydrates, proteins, and lipids into smaller molecules that can be absorbed into cells that lines the small intestine. Enzymatic digestion of macromolecules is performed by carbohydrases (which digest carbohydrates), lipase (which digests fats), proteases (which digest larger polypeptides), and nucleases (which digest nucleic acids).

Answer 72

Two factors, temperature and pH, can affect the rate at which an enzyme functions to break down complex molecules. More energy is added at higher temperatures, so the enzyme activity increases. The chemical bonds become too weak to maintain the enzyme's shape. The enzyme becomes denatured, meaning that its molecular shape and structure are changed. For most human enzymes, the optimal temperature range is fairly narrow, peaking at about 37°C. Enzymes function best within an optimal pH range. Some human enzymes, such as pepsin, function best at low pH. Pepsin is found in the acidic environment inside the stomach. However, most human enzymes, such as trypsin, function best in pH environments of about pH 6 to 8. Trypsin is found in the more neutral environments of the small intestine.

Answer 73

Monosaccharides are absorbed into the bloodstream through the lining of the small intestine. They are transported to the liver, where monosaccharides (other than glucose) are converted into glucose. Glucose is carried from the liver to all the parts of the body by the circulatory system, and is used by cells as a source of energy. The liver converts excess glucose into glycogen, which can temporarily stored in the liver and, in much smaller amounts, in muscles. When the body needs additional energy, some of the stored glycogen is converted back to glucose.

Answer 74

Like monosaccharides, amino acids are carried by the bloodstream form the small intestine directly to the liver. In the liver, amino acids are processed by various reactions and either converted into sugars or used in energy-releasing chemical reactions. Some of the amino acids resulting from these reactions undergo a series of further transformations in the liver, and become a part of a nitrogen-rich waste called urea. Urea is filtered by the excretory system and expelled from the body in urine. Other amino acids are carried by the circulatory system to the cells of the body.

Answer 75

Glycerol and fatty acid molecules are absorbed into the cells of the small intestine, where they are reassembled to form triglycerides. The triglycerides are coated with proteins to make them water-soluble. Protein-coated triglycerides pass from the cells of the small intestine into a network of vessels that transfer them into the bloodstream. In the blood, the protein coating is removed and the triglycerides are broken down by lipase enzymes back to glycerol and fatty acids. The smaller molecules provide energy to the cells.

Answer 76

After the nutrients in digested food have been absorbed from the small intestine into the bloodstream, the remaining material moves into the large intestine, or colon. This part of the digestive system is much shorter and wider than the small intestine. The main function of the large intestine is to absorb water from the alimentary canal. About 90% of the water is absorbed back into the blood and extra-cellular fluids. The volume of the indigestible food matter is therefor reduced by about two thirds.

Answer 77

Billions of anaerobic bacteria in the colon break down undigested matter further. Some of these bacteria produce important vitamins, including folic acid, several B vitamins, and vitamin K, which are absorbed into the bloodstream through the colon. The leftover matter forms feces, which are pushed by the muscular contractions of the colon into the rectum. The rectum stores the feces until they are eliminated at the anus.

Answer 78

A sore in the lining of the stomach or duodenum, most commonly caused by infections with the bacterium Helicobacter pylori.

Answer 79

Peptic ulcer symptoms: - abdominal pain, bloating, nausea, and loss of appetite - Helicobacter pylori attaches themselves to the all of the digestive tract and prevents it from producing mucus. - Exposed unprotected tissue comes in contact with acidic gastric juice.

Answer 80

Peptic ulcer treatment: Because ulcers are caused by a bacterium, they can be treated with antibiotics that kill the bacteria. Along with antibiotics, doctors also prescribe medications that reduce acidity in the stomach. Treatment may also include lifestyle changes, such as losing weight if overweight, including alcohol and not smoking.

Answer 81

The general name for a group of diseases that cause inflammation in the intestines

Answer 82

IBD symptoms: - Inflammation of the intestines - long lasting and reoccurring - pain and inflammation

Answer 83

IBD treatment: - IBD can only be treated -- not cured -- by a special diet and by taking medication to reduce pain and inflammation. - In severe cases of IBD, it may be necessary for surgeons to remove the affected part of the colon and create a new external opening for digestive waste.

Answer 84

A form of inflammatory disease that can affect any part of the alimentary canal from the mouth to anus

Answer 85

Crohn's disease symptoms: - Children with Crohn's disease generally do not grow properly during puberty. - They develop thinner bones that increase the future risk of fractures, and they experience poor muscle development.

Answer 86

A form of inflammatory disease that attacks the colon

Answer 87

Ulcerative colitis symptoms: | - Loose and bloody stools, cramps, and abdominal pain.

Answer 88

Inflammatory bowel disease is a general name for a group of diseases that cause inflammation of the intestines. Crohn's disease is a form of inflammatory bowel disease that can affect any part of the alimentary canal from mouth to anus. Ulcerative colitis is a form of inflammatory bowel disease that attacks the colon.

Answer 89

Constipation is a common disorder of the digestive system in which bowel movements are reduced to three per week or less and stools are dry, small, and difficult to eliminate.

Answer 90

Constipation can be caused by inadequate water intake and lack of good nerve ad muscle function in the bowel. An unhealthy diet and lack of physical activity can also cause constipation.

Answer 91

The bulk and soft texture of fibre helps prevent constipation. Most dietary fibre is made up of cellulose, which humans are unable to digest, and passes through the body almost unchanged. Fibrous foods: whole grain bread, brown rice, oats, beans, peas, lentils, grains seeds, some fruits, and vegetables.

Answer 92

Inflammation of the liver, most commonly caused by a virus

Answer 93

Hepatitis symptoms: | inflammation of the liver

Answer 94

Hepatitis A is usually contracted from drinking contaminated water. Hepatitis B is spread by sexual contact but there is a vaccine to protect against it. Hepatitis C is usually contracted by contact with infected blood. There is no vaccine for hepatitis C.

Answer 95

The irreversible replacement of healthy liver tissue with non-functioning scar tissue; most commonly caused by excessive alcohol intake or hepatitis.

Answer 96

- Scar tissue replaces healthy liver tissue and prevents the liver from functioning properly. - few symptoms in early stages - Liver becoming fatty -- early warning sign

Answer 97

Liver transplant is primary treatment for liver failure. Liver has the ability to heal itself, but in many cases there is not enough regeneration to avoid liver failure. Blood test can determine if liver is becoming fatty.

Answer 98

Small hard masses that form in the gall bladder

Answer 99

Cholesterol precipitates out of bile and forms crystals Crystals grow and become gallstones Related factors: obesity, alcohol intake, and heredity

Answer 100

Treated w/ medications or w/ ultrasound shockwave to disintegrate the stones so that they can be passed out in the urine. Cholesterol in the gall bladder can be lowered by losing weight, increasing the intake of omega-3 fatty acids, and decreasing the size of meals. The gall bladder may need to be surgically removed if gallstones are serious.

Answer 101

a. Constipation is a condition in which bowel movements are infrequent and strained. It can be caused by inadequate water intake, inadequate fibre in the diet, and lack of good muscle and nerve function in the bowel. b. Hepatitis is an inflammation of the liver caused by contaminated drinking water (Hep A), through sexual contact (Hep B), or contact with infected blood (Hep C). c. Cirrhosis is a chronic disease in which scar tissue replaces healthy liver tissue and the liver ceases to function properly. Cirrhosis is most commonly caused by chronic alcoholism and hepatitis C.

Answer 102

- An endoscope is a medical device with a light attached, used to look inside a body cavity or organ - It is a non-invasive method to confirm medical problems - Other attachments that can be fitted to the endoscope include a camera; a laser; and tiny forceps. - The capsule endoscope - a tiny camera placed inside a capsule that can be swallowed. - Useful for seeing inside the small intestine.

Answer 103

A condition in which the body is unable to use glucose for energy

Answer 104

- The pancreas secretes insulin that regulates the absorption of glucose from the small intestine; diabetes results when there is insufficient insulin to regulate blood glucose levels. - Diabetes is a chronic disease in which the body cells are unable to use glucose for energy - Normally, insulin is released from the pancreas, which glucose in the bloodstream to enter the body’s cells - A person with diabetes cannot produce enough insulin or the body cannot properly use the insulin - Therefore, glucose cannot enter the cells and the blood glucose levels increase to life-threatening levels

Answer 105

- When either the body does not make enough insulin or it is unable to properly use the insulin it makes (insulin resistance) - Often diagnosed in people over the age of 40 - Causes: genetics and lifestyle - The increased sedentary lifestyle of Canadians has increased the prevalence of Type 2 diabetes - It can be treated/managed - Improved diet - Regular exercise/maintaining a healthy weight - Medications to control blood sugar - Self-management through lifestyle

Answer 106

Gestational Diabetes - Develops during pregnancy - Results from pregnancy hormones or inadequate levels of insulin production - Often ends when the baby is born

Answer 107

Type 1 - Aka “juvenile diabetes” or “insulin-dependent diabetes” - When insulin-producing cells of the pancreas are destroyed by the immune system and therefore no longer produce insulin - Most often diagnosed in children, teens, and young adults - Treated with insulin injections

Answer 108

In 1922, Canadian scientists Frederick Banting and Charles Best discovered the connection between insulin and diabetes Therefore, they demonstrated that insulin injections could help people with diabetes

Answer 109

People with diabetes must monitor their blood glucose levels and inject insulin into their bloodstream when it is needed

Answer 110

Genetically engineered human insulin and computerized insulin pumps are some of the technological innovations used in the control and maintenance of blood glucose levels.