The Remarkable Body Chapter 3 Nutrition Concepts Controversies

The Remarkable Body Chapter 3 Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Learning Objectives n n Describe the levels of organization in the body, and identify some basic ways in which nutrition supports them. Describe the relationship between the body’s fluids and the cardiovascular system and their important to the nourishment and maintenance of body tissues. Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Learning Objectives n n Summarize the interactions between the nervous and hormonal systems and nutrition. State how nutrition and immunity are interrelated, and describe the importance of inflammation to the body’s health. Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Learning Objectives n n Compare the terms mechanical digestion and chemical digestion, and point out where these processes occur along the digestive tract with regard to carbohydrate, fat, and protein. Name some common digestive problems and off suggestions for dietary alterations that may improve them. Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Learning Objectives n n Identify the excretory functions o the lungs, liver, kidneys, and bladder, and state why they are important to maintain normal body functioning. Identify glycogen and fat as the two forms of nutrients stored in the body, and identify the liver, muscles, and adipose tissue as the body tissues that store them. Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Learning Objectives n Define the term moderate alcohol consumption, and discuss the potential health effects, both negative and positive, associated with this level of drinking. Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body’s Cells n n n Body is composed of trillions of cells Body needs nutrients Cells are self-contained, living entities Depend on one another n Basic needs n Essential nutrients n n Cells die at varying rates Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

A Cell (Simplified Diagram) Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body’s Cells n Genes Control Functions Direct production of proteins n Provide instruction for structural components of cells n Affects how body handles nutrients n Complete set of genes in each cell n Gene variations n Inborn error of metabolism n Influence of nutrients n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

From DNA to Living Cells Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body’s Cells n Cells, tissues, organs, systems Cells into tissues n Tissues into organs n Organs together as part of body systems n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body Fluids and the Cardiovascular System n Body fluids Supply energy, oxygen, nutrients, and water n Deliver fresh supplies and pick up wastes n n Circulating fluids Blood n Arteries, veins, capillaries n Plasma n Lymph n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Blood Flow in the Cardiovascular System Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body Fluids and the Cardiovascular System n n n Plasma Extracellular fluid Intracellular fluid All cell reactions take place n Holds cellular shape n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body Fluids and the Cardiovascular System n All blood circulates to the lungs Picks up oxygen n Releases carbon dioxide n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body Fluids and the Cardiovascular System n Blood returns to heart n n Blood pumped to rest of body n Delivers nutrients & picks up wastes Blood passes through digestive system Picks up nutrients n Except for fats n Fats travel via lymph n Routed directly to liver n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Lymph Vessels and the Bloodstream Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Body Fluids and the Cardiovascular System n Kidneys n n Cleansing of wastes Fluid intake Red blood cell life expectancy Blood is sensitive to malnutrition Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Hormonal and Nervous Systems n Hormones Chemical messengers n Secreted and released directly into blood by glands n Stimulate organs to take action n n Glands monitor conditions in the body n Pancreas n Insulin and glucagon Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Hormonal and Nervous Systems n Nutrition affects the hormonal system n n Hormones affect nutrition n Examples Nervous system Receives and integrates information from sensory receptors n Role in hunger regulation n Cortex and hypothalamus n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Cutaway Side View of the Brain Showing the Hypothalamus & Cortex Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Hormonal and Nervous Systems n Fight-or-flight reaction (stress response) Neurotransmitters n Epinephrine and norepinephrine n Metabolism speeds up n Organ response n Eyes, heart, liver, stomach n Heart disease n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Immune System n Cooperation among tissues to maintain defenses n n n Physical barriers Antigen Immune defenses n White blood cells n Phagocytes n Lymphocytes (T-cells and B-cells) Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Immune System n Inflammation Response to injury or irritation n Increased white blood cells, redness, heat, pain, swelling n Normal and healthy response n Problem with chronic inflammation n Dietary factors n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Digestive System n Five basic chemical tastes n n n Sweet, sour, bitter, salty, and umami Other factors affecting experience of food flavor Sweet, salty, and fatty foods Almost universally desired n Can lead to drastic overeating of these substances n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Innate Preference for Sweet Taste Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Digestive System n Digestive tract Flexible, muscular tube n Path n Total length of about 26 feet n Body surrounds digestive canal n n System’s job is to digest food to its components, absorb, and excrete n System works at two levels Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Digestive System Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Digestive System n Mechanical digestion Begins in the mouth n Chewing n Stomach and small intestine n Peristalsis n Chyme travels through pyloric valve n Large intestine n Digestion is virtually continuous n Sleep and exercise n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Peristaltic Wave Passing Down the Esophagus and Beyond Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Muscular Stomach Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Digestive System n Chemical digestion Digestive juices n Salivary glands, stomach, pancreas, liver, and small intestine n Mouth n Saliva – starches and fat n Saliva – health of teeth n Stomach n Hydrochloric acid – protein n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

p. H Values of Digestive Juice and Other Common Fluids Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Digestive System n Chemical digestion n n Intestine n Bile n Pancreatic juice n Digestive enzymes in wall of intestine n Fiber Food combinations and digestion Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

“I Am What I Eat” n Within 24 to 48 hours n n 90% of carbs, fat, and protein are digested and absorbed Mouth Food is crushed, mashed, and mixed with saliva n Carbohydrate digestion begins n Swallowing n Peristalic waves n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

“I Am What I Eat” n n n Stomach n Gastric juice mixes with food n Unwinds proteins n Chyme Small intestine n Bile from the liver n Pancreas Large intestine Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Typical Digestive System Transit Times Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

“I Am What I Eat” n Absorption Nutrient molecules transverse intestinal lining n Water-soluble components n Fat-soluble components n Cells of small intestine are selective n Folded structure n Villi n Microvilli n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Details of the Small Intestine Lining Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

“I Am What I Eat” n Transport Lymph vessels n Products of fat digestion n Fat-soluble vitamins n Blood vessels n Products of carbohydrate & protein digestion n Most vitamins n Minerals n n Nourishment of digestive tract Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

A Letter from Your Digestive Tract n n n Hiccups Fiber and gas Heartburn n Antacids GERD Ulcers Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

A Letter from Your Digestive Tract n n Choking Constipation & diarrhea n n Hemorrhoids Irritable bowel syndrome (IBS) Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Normal Swallowing and Choking Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

First Aid for Choking Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Excretory System n Organs involved in waste removal n n Lungs, liver, kidneys Kidneys Waste materials are dissolved in water n Working units – nephrons n Urine is stored in bladder n Sodium and blood pressure n Work regulated by hormones n Importance of water supply n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Storage Systems n n Eating intervals of 4 -6 hours Major storage sites Liver – carbohydrates n Glycogen n Muscles – carbohydrates n Glycogen n Fat cells – fat and fat-related substances n n Variations in nutrient stores Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol and Nutrition: Do the Benefits Outweigh the Risks? Controversy 3 Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

U. S. Alcohol Consumption n Total daily energy intake as alcohol n n U. S. average of 6 to 10 percent Drinking pattern Binge drinking n Heavy drinking n Moderate drinking n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Does Moderate Alcohol Use Benefit Health? n Influence of age n n Influence of drinking patterns n n Middle-aged people Light to moderate intakes Health benefits of wine n Science is mixed Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

What is Alcohol? n n n Names end in –ol Act as lipid solvents Ethanol n n Alcoholic beverages Social interactions n Nonalcoholic beverages Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

What is a “Drink”? n n Beverage volume Proof n n Percentage of alcohol Defining a drink Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Drinking Patterns n Defining moderation Difficulties with defining n Health authority definition n n Problem drinkers and alcoholism Irrational and dangerous behaviors n Health effects n n Heavy episodic drinking Defined n Harms n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Behaviors Typical of Moderate Drinkers and Problem Drinkers Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Immediate Effects of Alcohol n n The body gives special attention to alcohol Diffusion through stomach walls Reach brain within a minute n Vomiting n Presence of food in the stomach n n n Absorption in small intestine Alcohol dehydrates tissues n Increased urine output Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol Arrives in the Brain n Nerves Inhibitory n Excitatory n n Lethal dose n n Speed and amount consumed Toxicity, oxidative stress, and the brain Brain tissue shrinks n Brain inflammation n n Accidents Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Effects of Rising Blood Alcohol Levels on the Brain Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol Doses and Average Blood Level Percentages Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Blood Alcohol and Traffic Accidents Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol Arrives in the Body n Liver processes most of the body’s alcohol n n Alcohol breakdown in the stomach n n n Alcohol dehydrogenase (ADH) n Acetaldehyde Women vs. men Excretion in breath and urine Rate of alcohol clearance Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol Breakdown Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol Affects the Liver n Alcohol metabolism generates damaging free radicals n n n Diseases and organ damage Fatty liver Liver fibrosis n Cirrhosis Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

The Hangover n n Mild form of drug withdrawal Contributors to hangovers Congeners n Dehydration n Formaldehyde n Methanol n n Sure cure for hangover Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol’s Long-Term Effects n n n Effects in pregnancy Effects on heart and brain Cancer n n Even moderate consumption increases risk Long-term effects of alcohol abuse Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Alcohol’s Effects on Nutrition n Causes disturbances in nutrition All discretionary calories Fattening power of alcohol n n “Beer belly” Effects on vitamins Malnutrition n Wernicke-Korsakoff syndrome n Folate n Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney

Calories in Alcoholic Beverages and Mixers Nutrition: Concepts & Controversies, 13 th edition, Sizer & Whitney