The Digestive System and Nutrition 13

Chapter 13: The Digestive System and Nutrition Lesson 13.1 Nutrition

Energy measuring the body’s energy use basal metabolic rate calories kilocalories basal metabolic rate energy required for one day at rest varies by individual

Vitamins chemicals needed for proper metabolism types of vitamins fat-soluble may be stored in the body water-soluble are not stored in the body vitamin deficiency

Minerals elements needed for proper body function examples calcium potassium iron phosphorus

Water-Soluble Vitamins

Fat-Soluble Vitamins

Minerals

DIET Deficiency diseases if you don’t eat a well balanced diet Vegetarians:  20 amino acids - 12 we can make, 8 we need to eat (essential amino acids) Grains have 6 aa Beans have 6 aa Mix beans and grains for complete aa

Fun facts 25ft long intestines in humans 89ft long intestines in horses Food drying up in large intestine can be there 18 hours-2 days Final destination Starch = blood Fat = lymph vessels Protein = blood

Anatomy and Physiology of the Digestive System Chapter 13: The Digestive System and Nutrition Anatomy and Physiology of the Digestive System Lesson 13.2

Activities/functions of Digestion (1) ingestion- take in food (2) propulsion moving food along GI tract peristalsis (3) mechanical breakdown breaks food into smaller pieces increases surface area of food

Activities of Digestion (4) chemical breakdown digestion enzymes (5) absorption digested food particles absorbed & moved into blood (6) elimination expulsion of food not absorbed

Activities of Digestion

Layers of the Alimentary Canal

Digestive Organs and Their Functions

Oral Cavity-Mechanical & Chemical digestion Mechanical digestion  Chew, tear, grind, mush, mix Chemical digestion (saliva) Amylase digest starch Mucus -protect lining of stomach GI tract; lubricate Buffers -neutralize acid to prevent tooth decay

Oral cavity- chem digestion Anti-bacterial chemicals - kill unwanted bacteria from food Epiglottis- flap in back of mouth; closes trachea, prevents food from entering lungs

Esophagus Esophagus Secretes mucus connects pharynx to stomach 10-12 inches long Secretes mucus Acid from stomach gets in here = heart burn Acid reflux Diaphragm prevents, along w/ esophageal sphincter

Stomach Storage of food Disinfects food HCl (pH = 2) Mucus-secreting Up to 2 Liters Disinfects food HCl (pH = 2) Mucus-secreting To not digest itself Protein-digesting: pepsin enzyme Chyme formation

Stomach (cont.) Rugae - folds in lining allow for expansion Pyloric sphincter - regulates food from stomach to intestine Ulcers: not caused by stress Bacterial infection of stomach

Small Intestines About 6 meters long Duodenum (25cm) receives stomach content Pancreatic juice & bile/neutralize acid/pepsin Jejunum (2.5m) Ileum (3.6m) reabsorb bile Digests carbs (amylase) Digest protein (trypsin) Digest lipids (bile and lipase)

Small Intestines…big absorption Absorb nutrients (diffusion & active transport) from capillaries to blood vessels Microvilli (projections) increase surface area 80% ingested water, vitamins, minerals

Large intestines Colon: ascending, transverse, descending, sigmoid Rectum & anus Elimination Undigested materials Cellulose (roughage) Keeps everything moving & clean MASSES of bacteria Appendix: vestigial organs

The Liver and Gallbladder functions of liver maintains nutrients in blood nutrient conversion and storage filters toxins functions of gallbladder stores bile made by liver releases bile when fat-containing chyme is in duodenum

Liver and Gallbladder

Pancreas pancreatic juices glucose regulation contain digestive enzymes Trypsin, amylase, lipase & buffers glucose regulation beta cells–insulin alpha cells–glucagon

Disorders and Diseases of the Digestive System Chapter 13: The Digestive System and Nutrition Lesson 13.3 Disorders and Diseases of the Digestive System

Disorders and Diseases of the Digestive System gingivitis and periodontal disease plaque forms tarter cardiovascular disease gastroesophageal reflux disease heartburn ulcers Helicobacter pylori

Disorders and Diseases of the Digestive System gastroenteritis inflammation of stomach or intestine inflammatory bowel syndrome chronic inflammation ulcerative colitis Crohn’s disease constipation and diarrhea infrequent or too frequent defecation

Disorders and Diseases of the Digestive System hepatitis inflammation of liver pancreatitis inflammation of pancreas gallstones bile forms crystals Cholecystectomy (bye, gb!) cancer digestive system cancers are common Roblan/Shutterstock.com