Nutrition – chapter 3 How nutrients become you

Objectives Identify the six basic food groups Identify the six basic food groups Distinguish the functions of the major parts of the digestive system Distinguish the functions of the major parts of the digestive system Describe the processes of absorption and metabolism Describe the processes of absorption and metabolism Explain factors affecting digestions and absorption Explain factors affecting digestions and absorption Name common digestive disorders Name common digestive disorders

FOOD, NUTRIENTS, AND ENERGY SIX NUTRIENT GROUPS *Carbohydrates*Fats*Proteins*Vitamins*Minerals*Water

The Chemistry of Nutrition Elements Elements Matter Matter –Atom –Molecule –Compound – when atoms of different elements are bonded together

Basic Nutrition Groups Compounds Compounds –Carborhydrates –Fats –Proteins –Vitamins –Water Minerals 25 chemical elements in this group – include oxygen, hydrogen, carbon, nitrogen, sulfur and cobalt

Functions of Nutrients Build and repair body tissues Build and repair body tissues Regulate body processes Regulate body processes Provide energy Provide energy –Energy value is measured in kilocalories – the amount of heat needed to raise one kilogram of water one degree Celsius

The process of digestion Process by which your body breaks down food. Process by which your body breaks down food. Mechanical digestion – food is crushed and chewed Mechanical digestion – food is crushed and chewed Chemical digestion – food is mixed with powerful acids and enzymes Chemical digestion – food is mixed with powerful acids and enzymes –Food travels through a muscular tube called the GI (gastrointestinal) Tract

Path of Digestion In the mouth – mastication (chewing) In the mouth – mastication (chewing) In the esophagus – 10 inch tube to the stomach In the esophagus – 10 inch tube to the stomach –Epiglottis closes over windpipe so food goes down the right pipe –Food is squeezed by peristalsis – involuntary action to push food through –In the stomach – gastric juices combine with food to make chyme; stomach wall secretes mucosa which helps soften food and protect stomach from acids; pepsin breaks down protein; food remains in stomach about 2-3 hours. –In the small intestine – 95% of digestion occurs here; Duodenum 12 inches Duodenum 12 inches Jejunum – middle section – about 4 feet long Jejunum – middle section – about 4 feet long Ileum – last section – 5 feet long Ileum – last section – 5 feet long Pancreas – elongated gland hehid the stomach; secretes bicarbonate which netualizes hydrochloric acid Pancreas – elongated gland hehid the stomach; secretes bicarbonate which netualizes hydrochloric acid Liver – bile – aids in fat digestion; bile is stored in the gallbladder Liver – bile – aids in fat digestion; bile is stored in the gallbladder In the large intestine – COLON – Solid waste (feces) is excreted through the rectum In the large intestine – COLON – Solid waste (feces) is excreted through the rectum

ABSORPTION OF NUTRIENTS Happens mostly in the small intestine Happens mostly in the small intestine Covered with villi Covered with villi –Water soluble –Fat soluble –Produce waste material

METABOLISM All the chemical changes that occur as cells produce energy and materials needed to sustain life All the chemical changes that occur as cells produce energy and materials needed to sustain life Cells break down some nutrients for energy (ATP) Cells break down some nutrients for energy (ATP) Adenosine triphosphate (ATP) is the source of immediate energy found in muscle tissue. Adenosine triphosphate (ATP) is the source of immediate energy found in muscle tissue. Body discards waste through the kidneys, lungs and large intestine Body discards waste through the kidneys, lungs and large intestine

FACTORS AFFECTING DIGESTION AND ABSORPTION Eating habits Eating habits Emotions Emotions Food allergies Food allergies Physical activity Physical activity

DIGESTIVE DISORDERS DiarrheaConstipationIndigestionHeartburnUlcerGallstonesDiverticulosis