Chapter 6The Human Organism andthe Importance of Nutrition Topics: Nutrition and Nutrients: the Digestive System Respiration and Energy: Respiratory System Transporting Nutrients: The Cardiovascular system Fighting Disease: The Lymphatic System Elimination of Waste: The Urinary System
Nutrition What it is and how to balance it
Nutrients • A nutrient is a substance found in food that is used by the body to meet important needs • In other words, it’s the stuff in food that we need. • Some nutrients give us • Some nutrients are useful in other ways. Energy
6 components to nutrition • 1. Carbs (carbohydrates) • 2. Protein • 3. Fats (lipids) • 4. Vitamins • 5. Minerals • 6. Water Energy Health
Carbs (carbohydrates) • For energy • Carbs (carbohydrate) go by many names • Sugar or starch • Simple sugars • complex carbohydrates, like starch, glycogen and cellulose • Starch sources: grains, pasta potatoes • Sources of sugar: nearly everything!!!
Protein • builds and maintains body tissue • creates all the structures of our bodies • hair, muscles, fingernails • Not all proteins are alike. • Proteins are made up of amino acids.
Protein • Essential Amino acids are a fundamental part of our diet. • 10 of the 20 amino acids are made by the human body • The other 10 cannot and must be eaten. • ***These other ten are "essential amino acids" • They can easily be provided by a balanced diet.*** • Protein as Energy source • Inefficient use of protein because • It must be used immediately or • the body converts protein to fat
Fats(lipids=fats, oil, waxes, sterols) • Contain twicethe energy per gram as either carbs or protein. • Important for getting your vitamins • Vitamins A, D, E and K require fats • You must eat fats along with these vitamins for your body to absorb them • They are “fat soluble” ( as opposed to water soluble)
Fats • In our body Fats are used for Energy Storage • Excess carbs and glucose are converted to fats. • Fat is also needed to: • cushion all organs • insulate against heat loss. • Fat becomes harmful in excess! • Stresses bones, muscles, heart and emotions
Cholesterol is found in fatty meat Cholesterol • Cholesterol is a type of fat that is found in most animals • It is needed for many processes, including: • Maintaining cell membrane flexibility • Making hormones • Cholesterol is: • Present in animal based foods • Not present in plant based foods • Your liver produces all you need • You don’t need to eat any extra! Too much cholesterol can clog up your arteries!
Vitamins and Minerals • Both are substances needed in tiny amounts for metabolic processes • Minerals are inorganic • Digesting food, building/repairing tissue, transporting materials etc • Are you getting enough? • Marked on food labels as % DV • Percentage daily value
Vitamins and minerals • Are you getting enough? • carefully plan your diet to include: • dairy foods, veggies, meats and fortified foods • Fortified = vitamins/minerals added (ie. Iodine in salt, vitamin D in milk etc.) • Or take a multivitamin that supplement your diet. • Does not replace a healthy diet
Focus Vitamins and minerals • Tough vits and mins to get enough of in your diet. • Calcium • What It Does • Keeps bones and teeth healthy • Helps nerves function • Regulates your heartbeat • Needed to make blood clot • Where you get it • Dark leafy greens, beans, dairy
Focus Vitamins and minerals • Vitamin D • What it does • forms bones and teeth • Helps immune function • Where to get it • Sun bathing • Vitamin D fortified milk • Salmon with bones/Sardines • Eggs and egg substitutes
Focus on Vitamins and Minerals Arrrghh! If you don’t get any vitamin C, you could get SCURVEY! • Vitamin C • What does it do? • Heals wounds and broken bones • Smokers should take 175% DV • Improves immunity • Where do I get it? • Fruits (esp. citrus), broccoli, cabbage Then your teeth might fall out!
Focus Vitamins and minerals • Vitamin B12 • What it do • Helps absorb food • Helps nervous system • Memory • Keeps blood cells healthy • Where you get it • Liver • Meat in general • Milk • Fortified cereals
Energy from Food • The amount of energy in food can be measured in: • DietaryCalories (Cal) • technically, a capital “C” dietary calorie is a kilocalorie, 1000 small “c” physical calories, but we will use the common approach and just call them Calories. • or Kilojoules (kJ) • One kJ = 4.19 Cal • So, if you know how many Calories a food has, just multiply by 4 to find its approximate kilojoules.
Why two different measures? • In Canada we are supposed to use kilojoules, in accordance with international standards • In the United States they mostly use Calories, so lots of our textbooks and cookbooks list food energy in Calories.
Energy from food • Only three of the six parts of your diet give you energy • Carbohydrates • 4 cal/g • Proteins • 4 cal/g • Fats • 9 cal/g
Energy needs • You need energy for everything your body does and even for your mind’s thoughts! • The basic energy requirements are keep your heart, brain and other organs going. • In addition any exercise you do requires energy based on • Intensity of activity • Your body mass
Energy in = Energy out? • The amount of energy we get from foodshould be equal to the amount of energy that we use. • If we get less energy from our food, we begin to starve. • If we get more energy from our food than we use, then our body stores the extra energy as fat. Energy
In other words… • If you use up 2000 Calories (8000 kJ) in a day by your activities… • Then you should eat food containing about 2000 Calories (8000 kJ) in order to replace your energy
How much do you need • Varies with age and sex • Adolescent girl : 1800-2400 Cal(7200-9600 kJ) • Adolescent boy: 2200-3200 Cal(8800-12800kJ)
What do you think this diagram means? Everything is related to nutrition What you eat, exercise, how well you care for yourself.
Another pyramid: the food pyramid • Eat only a little of the stuff on top: Sweets and carbohydrates • Eat a bit more meat and dairy • Eat even more fruit and vegetables • Eat mostly foods with lots of grain and fibre, like bread, cereal, rice and
Eat… • Lots of grain and fibre-rich food. • Quite a bit of fruit and vegetables. • Some meat and dairy. • Just a little bit of dessert.
Filling in the Calories Used Table 8 h 10 h 2 h 3 h 1 h 480 900 240 510 300 2430 1920 3600 960 2040 1200 9720 Conclusion : Yesterday I used approximately 2430 calories of energy (or about 9720 kilojoules)
Cereal / Milk Toast / butter Egg Bacon 1 2 1 3 110 65 75 35 110 130 75 115 440 520 300 460 430 1720
Exercises and Assignments • Text Book • Read pp. 159 to 166 • Do page 194, question #1 to 3 • Workbook • Do pages 89, 90, 91 and 92
The Digestive System -a one way tube through the body Topics: Digestive Tract vs. Glands Digestion and absorption The organs of the tube
Two Main Parts of Digestive System • I. The Digestive Tract • 1) Mouth Ingests and chews food • 2) Pharynx Forms food into a bolus & swallows • 3) Esophagus Carries food to the stomach • 4) Stomach Churns food into chyme • 5) Small Intestine Absorbs nutrients from food • 6) Large Intestine Absorbs water from waste • 7) Rectum & Anus Eliminate waste food solids • II. The Digestive Glands • A) Salivary Glands Secrete saliva • B) Gastric Glands Secrete stomach acid, mucus and pepsin • C) Liver (with gall bladder) Secretes bile • D) Pancreas Secretes pancreatic juice • E) Intestinal Glands Secretes digestive enzymes & mucus
Digestion • Your digestive system digests two ways • Chemically • Acids and enzymes react with foods to release their nutrients • Physically/Mechanically • Food is smooshed, torn and broken down into smaller pieces to releases nutrients
Absorption • After food has been digested • Nutrients from food leave your digestive tract • And are absorbed into your blood
Digestive Tract Associated Glands & organs 2 1 Pharynx A 1 The Mouth (AKA:oral cavity) Pharynx Esophagus Stomach Small intestine (duodenum) (jejunum) (ileum) Large intestine (Ascending colon) (Transverse colon) (Descending colon) (Sigmoid colon) Rectum Anus Salivary glands (saliva) Gastric glands (stomach lining) (digestive juices) (acid & enzymes) Liver (bile) Gall Bladder (bile storage) Pancreas (pancreatic juice) Intestinal Glands Appendix (no function) Amylase 3 A 2 B 3 Pepsin Acid B C 4 C 4 5 Bile D Pancreatic Juice 5 D mucus 6 6 * E 7 * 7b 7 7b
Organs of the tube:1. Mouth • Mechanical digestion (physical breakdown) • Teeth • Chemical digestion (digestive enzymes) • Saliva • Under control of nervous system • Contains: Lysozyme (antibacterial enzyme) Amylase (breaks down starch) Teeth Palate Uvula Salivary Gland Tongue
2. The Pharynx • The pharynx is your throat. It determines whether we are breathing or swallowing • We can’t do both at the same time • A small muscular flaps, the uvula and the epiglotis control this. • When we are breathing, they open a passage from our nose to our lungs. • When we swallow, they close off the lungs, and force the food into our esophagus Uvula Epiglottis Food Air
3. Esophagus • Tube that pushes bolus from the mouth to the stomach • bolus = food clump • The pushing is done by Peristalsis(click on word for animation) • wave of muscle contractions • Peristalsis pushes our food through the entire digestive system • Heartburn is stomach acid burning the bottom of the esophagus
4. The Stomach • Mechanical digestion in the stomach: • Stomach muscles churn to produce chyme • Chyme is mushed up food in stomach • Chemical Digestion in the stomach: • Gastric glands in the stomach lining secrete mucus and hydrochloric acid. Acid also activates release of pepsin • Ulcers : • Painful hole in stomach caused by excess acid or bacteria
5. The Small Intestine • Starts right after the stomach • Many enzymes and chemicals break down food • Enzymes and chemicals are injected from the pancreas and liver • ABSORBS nutrients. • Small intestine is lined w/villi (tiny projections) covered w/microvilli • Peristalsis pushes bolus along to large intestine
The Pancreas (a Gland) • Pancreas – gland just below the stomach • Pancreatic juice neutralizes stomach acid • Works like “baking soda” to get rid of excess acid. • Produces enzymes (like amylase) that break down macromolecules • The Pancreas also releases insulin into blood.
The Liver (a Gland) • Liver – large organ just above the stomach • Produces bile (breaks down fat) • Also vital for removal of toxins from body
6. The Large Intestine • Recovers water (absorbs it back into the blood) • Forms and stores feces (waste) • Microbial fermentation to digest indigestible foods (cellulose/wood) • Pushes waste to rectum by peristalsis
7. The Rectum Rectum • The rectum holds feces until they leave the anus • The anus is a sphincter muscle • When you go #2 the sphincter relaxes • When you hold it, the sphincter contracts • Peristalsis pushes feces out of your body Anus
Large Intestine (colon) Large intestine Small Intestine
Organs of the Digestive Tractmajor organs are numbered, connections are not Digestive Tract organ connection Function connects • 1. Mouth mechanical digestion • 2. Pharynx Epiglottis mouth esophagus • 3. Esophagus moves food bolus Cardiac sphincter esophagus stomach • 4. Stomach digestion Pyloric valve stomach small intestine • 5. Small intestine digestion absorbs nutrients ! Cecum small intestine large • 6. Large intestine absorbs water • 7. Rectum holds feces until released. Anal sphincter Rectumoutside
Glands of the Digestive System • What the glands & organs secrete: • Salivary glands amylase digests starch (in mouth) lysozyme kills bacteria • Gastric Glands acid dissolves foods (in stomach lining) pepsin digests protein mucus protects stomach • Liver & gall bladderbile digests fats • Pancreas pancreatic neutralizes acid juice helps digest fats & carbs insulin absorbs carbs into blood into blood Mouth Stomach Intestines
Exercises and Assignments • Text Book • Read pages 167 to 171 • Do Questions 4 and 5 on pages 194 to 195 • Workbook • Do 93, 94, 95, 96, 97, 98
The Respiratory System Topics: Respiration? Parts of the resp sys Breathing
Respiratory System • Respiration is the process by which we get from nutrients. • Carbs, Fats and Proteins can provide us with energy if they are OXIDIZED by mitochondria or our cells. • To oxidize these nutrients, we need • Getting this oxygen into our blood is the job of the respiratory system. energy oxygen