Presentation on theme: "Human Digestive System. Study Guide Answer 26. order of the organs of digestion: mouth esophagus esophageal sphincter stomach pyloric sphincter small."— Presentation transcript:
Human Digestive System
Study Guide Answer 26. order of the organs of digestion: mouth esophagus esophageal sphincter stomach pyloric sphincter small intestine common bile duct/gall bladder/liver pancreatic duct/ pancreas appendix large intestine rectum anal sphincter
Ingestion Ingestion is the process of placing food into your mouth.
Mouth Digestion - Mechanical Mechanical (Physical) Digestion – breaking the food into smaller and smaller pieces without changing the chemistry of the food. Only the size of the pieces changes!
Study Guide Answer 1. mechanical digestion- the process by which food particles are physically broken down into smaller pieces without changing the chemical composition of the food. This process begins in the mouth where the teeth masticate food and continues in the stomach where the three layers of muscle contract to grind the food up even further. By making the pieces smaller, the chemicals of the digestive process are able to touch more surface area of the food.
Study Guide Answer 32. ingestion and mastication (chewing) – Ingestion is the process of putting food into your mouth. When you chew it, it is called mastication.
Mouth Digestion - Chemical Chemical Digestion – amylase and ptyalin are two salivary enzymes that break starches down into simpler chemical substances called sugars.
Study Guide Answer 15. starches and sugars – Starches are molecules made up of long chains of sugars. When digested, starches are broken down into these sugars. Starch digestion begins in the mouth, where the salivary enzymes chemically attack the starches and break them down into individual sugars. Sugars are chemicals that end in “ose.” Fructose, lactose, maltose, and glucose are all sugars. A person should consume only about 40 grams of sugar a day. 16. carbohydrates – Carbohydrates are another name for starches. Complex carbs is a term given to starches that have not been processed. Whole grains are an example of complex carbohydrates. Simple carbohydrates are usually processed whole grains. Wheat is stripped of its outer bran and then ground and bleached. This becomes white flour from which many crackers, breads, rolls, pizza crusts, and cookies can be made. It has to be vitamin fortified since the nutritious bran has been removed. Carbohydrates are also found in beans or other starchy vegetables. When digested, the simple sugars are released and absorbed into the blood stream.
Study Guide Answer 2. chemical digestion – the process by which food particles are chemically altered so that they can be more easily used by the body. Many organs of the body make chemicals of digestion. The salivary glands, stomach, liver, and pancreas all make digestive chemicals.
Study Guide Answer 18. glands and secretions – There are many groupings of specialized cells called glands that make chemicals that the body needs. Sweat glands in the skin, salivary glands in the cheek and under the tongue, and the pituitary gland in the brain, are all examples of glands.
Saliva and Salivary Enzymes When you chew (masticate) you make the pieces smaller and you mix the food with the saliva. Saliva contains special chemicals called enzymes that immediately start to chemically digest starches into sugars.
Study Guide Answer 3. saliva and salivary glands (parotid and sublingual) – the saliva-producing glands make saliva (spit). This keeps your mouth moist so that you can talk and chew food. Saliva makes food easier to swallow. Saliva contains enzymes that start the process of chemical digestion on starches. Both amylase and ptyalin are salivary enzymes that help chemically break down starches into sugars.
Study Guide Answer 4. amylase and ptyalin – these two salivary enzymes chemically change starches (bread, pasta, crackers, cookies, etc.) into simpler sugars that can be absorbed by the bloodstream. 5. enzymes – these are special chemicals that act on specific foods to alter them chemically. Enzymes are made by the body by specific organs. The pancreas makes pancreatic juice which contains enzymes to digest all types of foods.
The Bolus is Swallowed As you continue to chew, the food mass becomes a ball- shaped bolus which is ultimately swallowed. The bolus travels down the esophagus and into the stomach. estion/images/5d4oesoph.gif
Study Guide Question 17. smooth muscle – This type of muscle is NOT striated (striped). It is NOT responsible for the movement of bones or the beating of the heart. It is found in the walls of the digestive system, sphincters, sweat glands, eye pupils, etc.
Peristalsis Peristalsis is the wave- like contraction of the smooth muscles lining the digestive tract. This squeezing action moves along the entire tract and helps push the digesting food in one direction. e/biobk/peristalsis.gif
Study Guide Answer 6. peristalsis - this is a wave-like contraction of the smooth muscle lining the digestive tract. Peristalsis begins in the esophagus when you swallow. It continues into the stomach and then to the small intestine and large intestine. Peristalsis helps move food along the digestive tract so that it can be digested, absorbed, and ultimately the unused food or waste eliminated.
Pharynx – The Back of the Mouth The area in the back of the mouth is called the pharynx. It connects the mouth and sinus/nose to the esophagus. This area is sometimes called the throat. gram-of-pharynx.gif
Study Guide Answer 7. uvula (the "punching bag" organ that hangs down) – The uvula is the small finger-like projection that hangs down in the back of the mouth. It acts as a sensory organ to let you “sense” when you have swallowed.
Study Guide Answer 7. The epiglottis is the tissue flap that covers the trachea (wind tube that goes to the lungs). It prevents you from choking on food as you swallow. If food enters the trachea, it can cause gagging, choking, or can even block the airway.
Sphincters A sphincter is a ring of smooth muscle that can open and close to regulate the movement of food through the digestive system. The sphincter between the stomach and the esophagus is called the esophageal sphincter. The sphincter between the stomach and the small intestine is called the pyloric sphincter.
Study Guide Answer 19. sphincter – Sphincters are rings of smooth muscle that can relax and close or contract and open the hole that lies in the middle of the sphincter. The pupils of the eye, the esophageal and pyloric sphincters on either end of the stomach, the anal sphincter at the end of the digestive system are all examples. 20. esophageal sphincter – This ring of smooth muscle is located at the entrance to the stomach. It closes to keep the contents of the stomach in the stomach. 21. pyloric sphincter – This sphincter is located at the end of the stomach where the small intestine begins. It opens and closes to regulate the quantity of chyme released into the small intestine from the stomach.
Esophageal Sphincter The Entranceway to the Stomach! odydigestive/727 Closed Sphincter Open Sphincter
Study Guide Answer 8. esophagus and trachea (which is which?) – the esophagus is the food tube and it takes food from the mouth to the stomach. It is lined with smooth muscle rings that contract to allow for peristalsis. The trachea is the air tube that takes air from the nose and mouth to the lungs and vis-versa. The trachea is semi-rigid and lined with rings of cartilage.
Stomach Digestion - Mechanical Mechanical Digestion – the stomach has three layers of smooth muscle, all going in different directions. These muscles can contract and relax, allowing the stomach to grind food up into smaller pieces. life.com/images/stomach_diagram.jpg
Stomach Digestion - Chemical The stomach makes hydrochloric acid that works with a stomach enzyme called pepsin. Together these two chemicals make up what is called gastric juice. Gastric juice chemically digests proteins.
Study Guide Answer 29. acid and base pH - neutralizing stomach acid – The inside of the stomach must remain acidic so that the gastric juice can work properly to digest proteins. However, sometimes the stomach acid levels become too strong and a person gets what is called “acid indigestion.” To decrease the quantity of acid in the stomach, an antacid medication can be taken. These medicines are chemically formulated to be “basic” which neutralizes the stomach acid relieving the burning symptoms of acid indigestion.
Digestion of Proteins Proteins are made up of long chains of amino acids. When digested, the chain is broken and the individual amino acids are released. The body then reassembles the amino acids to make new proteins that your body can use. tchers.net/images/ amino_acid_chain.j pg
A Little More Complicated Than That Image of a single amino acid:
Image of Different Types of Proteins Simplest Type Most Complex Type
Study Guide Answer 9. hydrochloric acid (HCl) – this strong acid is made by the cells of the stomach. It works with pepsin (a stomach enzyme) to begin the chemical digestion of proteins. 10. pepsin – this stomach-made enzyme is specific for the digestion of proteins. It works in an acid environment only. Therefore, the hydrochloric acid of the stomach is necessary for the pepsin to work to digest proteins. When proteins are chemically digested, they are broken apart into their amino acids. The body can then absorb the amino acids and reassemble them to make new proteins that the body can use.
Study Guide Answer 11. gastric juice – this is the combination of hydrochloric acid and pepsin made by the cells that line the stomach. The gastric juice does not harm the protein in the walls of the stomach because of the mucus (also made by stomach cells) that coats the entire inside of the stomach wall.
Study Guide Answer 14. proteins and amino acids – Proteins are molecules made up of long chains of amino acids. The order and types of amino acids in the chain determines what type of protein will be made. The healthy diet consists of many different types of proteins. Chemical digestion of protein begins in the stomach where hydrochloric acid and pepsin work together. When the digestive system breaks apart a protein, the individual amino acids can be reassembled to make a new protein that the body can use. A teenager needs about 40 – 50 grams of protein a day. Without protein we cannot make healthy cells, especially muscle cells.
Study Guide Answer 12. calorie – A calorie is a unit of measure for the quantity of heat energy it takes to raise one kilogram of pure water one degree Celsius. Foods are actually combusted (burned in the presence of oxygen) in special laboratory devices called calorimeter to see how much heat energy they release. This is how a food’s calorie content is determined. As your body moves and works during the day, you use up the calorie content of the food you have eaten. If you consume more calories than you use up, you gain weight in the form of fat. If you use up more calories than you consume in the food you eat, then you loose weight.
Pyloric Sphincter The pyloric sphincter (valve) is located where the stomach ends and the small intestine begins.
Small Intestine Digestion - Chemical Helper organs contribute digestive enzymes into the small intestine to enhance the chemical digestion of food. The liver makes bile which is stored in the gall bladder. The pancreas makes pancreatic juice.
Helper Organs The helper organs are the liver, gall bladder, and pancreas. Food DOES NOT pass through the helper organs.
Ducts Transport Chemicals Bile Duct - The gall bladder releases bile into the bile duct. The duct connects to and releases the bile into the upper part of the small intestine. Pancreatic Duct - The pancreatic duct transports pancreatic juice to the upper part of the small intestine.
Fats and Oils 13. fats and oils – There are many different types of fats. Oils are fats that are liquids at room temperature. The chemical composition of fats makes a difference in how our bodies use them. Fats are a necessary part of human nutrition and health. Without fats we could not make cells, hormones, and our hair and skin would be very dry. Fully saturated or hydrogenated trans fats are not good for us. Many saturated fats are found in animal products (meat and dairy). Trans fats are artificially made by bonding extra hydrogen molecules to an already existing fat. Unsaturated fats are healthier. Mono and polyunsaturated oils are good for us. Your total diet should not consist of more than 41 – 58 grams of total fats of all kinds in any one day.
Duodenum of the Small Intestine The first 29 cm of the small intestine is called the duodenum. ges/en/annular-pancreas-picture.jpg
Duodenum and Ducts The bile duct and the pancreatic duct connect to the duodenum.
Study Guide Answer 27. helper organs – What are they and what do they do? Liver – makes the emulsifying chemical bile which mechanically digests fats and oils. Gall Bladder – small organ attached to the liver that stores the bile. Bile Duct – a tube that attaches the gall bladder to the duodenum. The bile is transported down the bile duct and is squirted onto the chime as it passes. The stimulation of this release of bile is triggered by the fats and oils in the chime.
Study Guide Answer 22. bile – The green chemical bile is made by the liver and stored by the gall bladder. It travels to the duodenum by the bile duct. It is an emulsifier. An emulsifier takes fat and oil and causes them to break apart mechanically into smaller and smaller globules (spheres). By emulsifying the fats and oils eaten in the diet, the body can better absorb them into the blood stream. Bile is a chemical that actually causes MECHANICAL digestion of a nutrient. The chemical composition of the fat or oil is not changed, but the sizes of the globules are just made smaller and smaller. 23. gall bladder and the bile duct – The gall bladder is the organ that is attached to the liver that stores bile (made in the liver). The bile duct is a tube that allows the bile to be transported from the gall bladder to the duodenum.
Study Guide Answer 24. pancreatic juice and the pancreatic duct – The pancreas makes a chemical called pancreatic juice. This liquid chemical is transported to the duodenum by the pancreatic duct. When food passes by the duct, it is squirted by the liquid pancreatic juice. Pancreatic juice chemically digests all different types of foods. 25. pancreas – This helper organ sits behind and below the stomach. It makes insulin which enters the bloodstream and allows glucose to be transported into cells. It also makes pancreatic juice which is a very strong digestive chemical that is squirted onto food as it passes the opening of the pancreatic duct in the duodenum.
Inside the Small Intestine Villi are finger-like projections that increase the surface area of the inside of the small intestine. isplay/GP2134.jpg
Study Guide Answer 35. purpose and structure of villi and micro-villi in the small intestine – The villi are finger-like projections that line the entire inside of the small intestine. Villi are made of cells. Hundreds of them (just like your finger is made of cells). If all the villi were cut open and spread out, the surface area would be as large as a tennis court.
Micro-Villi Every villi is totally coated with micro-villi to increase absorption even more!
Inside the Small Intestine
The Appendix The appendix is located in the area where the small intestine meets the large intestine. fitness.com/images/appendix.gif
What Is the Appendix For? It is NOT where humans used to digest twigs and leaves. It IS now considered to be a place where the “good” bacteria can be stored for emergencies. Click on the image above to learn more.
Large Intestine – The Colon The large intestine is where most of the water is absorbed back into the blood stream. The large intestine is where the “good” bacteria live. These small organisms work to digest the cellulose and to make vitamins.
Rectum The rectum holds feces (poop) until it is time for it to be eliminated. um.300x300.jpg
Study Guide Answer 36. rectum – This part of the digestive tract is after the large intestine and before the anal sphincter. Fecal material is stored in the rectum until you go to the bathroom.
Anal Sphincter The anal sphincter is the last sphincter of the digestive system. It allows the feces to be held inside until they can be eliminated from the body.
Study Guide Answer 37. anal sphincter – This is the last sphincter of the digestive system. It is located between the rectum and the outside of the body. This sphincter holds in your solid wastes until you choose to eliminate them.
Study Guide Answer 28. voluntary vs. involuntary muscle movement – Voluntary muscle movement is controlled by your motor cortex of the brain. You think about moving a body part, a signal leaves the brain and travels to the appropriate skeletal muscles and the body part moves when the muscles contract. Involuntary muscle movement usually involves both smooth muscle and cardiac muscle. These muscles are moving as needed without conscious thought.
Study Guide Answer 30. diffusion (passive transport) and H L concentrate gradient compared to active transport – Diffusion is the movement of molecules through the semi-permeable cellular membrane into and out of the cytoplasm of the cell. Diffusion is considered passive transport since the cell does not need to make special transport molecules for it to occur. Active transport, on the other hand, involves the movement of larger and more complicated molecules into and out of a cell. Therefore the cell has to expend energy to make the special transport molecules that will open up the cell membrane and/or carry the large molecules into and out of a cell. 31. absorption/cell membrane/capillary beds – Like a sponge soaking up water, the wall lining the inside of the small and large intestine are able to absorb nutrients from the food you have eaten.
Study Guide Answer 33. cellular respiration and ATP production (aerobic and anaerobic) – The body cells use glucose to make ATP, a chemical that is used for cellular energy. Aerobic = C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy (34-36 ATP + heat) Anaerobic = 2ATP"+ C 6H 1206 Enzymes 2CH3CH2OH + 2CO2 + 4ATP 34. mitochondria – This cell organelle is called the “powerhouse of the cell” because this is the place where cellular respiration occurs.