Transcript Nutrition
Nutrition What are Nutrients? Nutrients • Provide energy • Need for growth, repair and maintenance of cells • Need for metabolism Nutrients • Examples (Why do we need each one?): – Proteins – Carbs. – Fats – Vitamins – Minerals – water Vitamins • Vit A – Vision – Fruits and Veg • Vit D – Bones – Dairy and skin exposed to sun • Vit K – Blood Clotting – Veg and rectal bacteria • Vit C – Bone, Cartilage, gums – Fruit and Veg • Vit B12 – Blood – Meat and Dairy Minerals • Fe – Blood • F – Teeth • Mg – Coenzyme • Ca – Bone and Teeth • P – Bone and Teeth • I – Thyroid • Na, K – Water balance (Osmosis), Nerve Function Essential Amino Acids • We can’t make 8 of the 20 amino acids – Need to eat meat and dairy products to get them How do organisms get nutrients? Nutrient Acquisition • Autotrophic Nutrition – Phototrophs (plants, algae cyanobacteria) • Use sun to convert inorganics (i.e.. CO2 and H2O) into organics – Chemotrophs (some bacteria) • Use CO2 and H2S to create organics • Heterotrophic Nutrition – Ingest plants and or animals for organics (Animals, bacteria, fungi, some protozoa) Energy in Food (ATP Potential) • calorie= – The amount of heat needed to raise the temperature of one gram of water one degree centigrade • Calorie (Kilocalorie [kcal]) (On side of food products)=1000 calories • 1g of Carb or Protein=4kcal • 1g of fat=9 kcal • Measure with Calorimeter Energy Needs • Humans-Just to live with no activity – 1,300-1,800 kcal/day • Unused Kcals – Stored in liver and muscles as glycogen – Stored as fat in adipose cells Food Pyramid (USDA)-Old Fiber • Indigestible materials • Fruits, veg, grains • Stimulates digestive system • Cleans out Colon and Rectal Cancer Cells Nutrition • Ingestion – Take food into organism • Digestion – Break food down Mechanically and/or Chemically – Can happen inside of cells (Intracellular Digestion) – Can happen outside of cells (Extracellular Digestion) • Absorption – Breakdown products enter cells • Egestion – Elimination of indigestible food waste Nutrition of Protists (Intracellular Digestion) Kingdom Protista Anal Pore Nutrition of Protists (Intracellular Digestion) Pseudopodia Food Vacuole Amoeba Nutrition in Hydra • Simple Multicellular Organism • Two cell layers (i.e.. Tissues) – Inner Endoderm – Outer Ectoderm • Tentacles with cnidoblast cells that have nematocysts inside • Mouth • Hydra eating Hydra • Extracellular digestion in gastrovascular cavity • Intracellular digestion after breakdown products absorbed • Egestion out mouth Nutrition in Worms • Multicellular • Tube within tube body plan (i.e.. body wall and digestive tubing) • Phylum Annelida Worm Worm Digestion Alimentary Canal= Digestive Tubing – Mouth=ingestion – Pharynx=sucks in food – Esophagus=food tube – Crop=Store food – Gizzard=grind food (Mechanical Digestion) – Intestine=chemical extracellular digestion, absorption (Typhlosole) – Anus=wastes out Grasshopper Nutrition • Phylum Arthropoda • Tubular digestive tract • Eats leafy vegetation Grasshopper Alimentary Canal Gizzard Pharynx +Esophagus Grasshopper Alimentary Canal • Mouth with chopping mouth parts – Ingestion – Food mixes with saliva from salivary glands • • • • Esophagus=food tube Crop= storage Gizzard=grinds food Stomach – Gastric Ceaca Digestive glands secrete enzymes into stomach for chemical extracellular digestion – Absorption • Intestine=absorption • Rectum=waste storage and elimination, H20 reabsorption Human Digestion When does digestion begin? Human Alimentary Canal 1. 2. 3. 4. 5. 6. 7. 8. Mouth Pharynx Esophagus Stomach Small Intestine Large Intestine Rectum Anus Accessory Glands (Inject fluids into the alimentary canal) 1. 2. 3. 4. Salivary Glands Liver Pancreas Gall Bladder 1. Mouth • Ingestion • Mechanical Digestion (Increase food surface area) • Saliva – Mucin (Lubricant) – Salivary Amylase (Breaks down Carbs into Maltose) • Tongue – Taste Buds – Shapes food into a Bolus Tongue Map No Longer Accurate! Taste Buds Teeth Teeth Hard, rich in calcium, eroded by acid 2. Pharynx 2. Pharynx •Back of Throat •Swallowing Reflex •Epiglottis closes trachea when swallowing Epiglottis 3. Esophagus • “Food Tube” • Lined with Smooth Muscle (Involuntary) • Squeeze food down (Peristalsis) 4. Stomach • Entrance controlled by Cardiac Sphincter (“Heart Burn”, Acid Reflux) • Stores and Churns food (Mechanical Breakdown) 4. Stomach • Makes Gastric Juice (Chemical Digestion) – Mucous Cells=make protective mucus – Parietal Cells=Make HCl (Denatures Proteins) – Chief Cells=Make Pepsinogen – G Cells= Produce Gastrin HCl Pepsinogen (Inactive) Pepsin (Active) Pepsin Proteins Small Polypeptides 4. Stomach 1. Food Sight, Thought, Smell, Empty Stomach – Brain stimulates stomach to make gastric juice 2. Food enters stomach causing more gastric juice production 3. Food mass stretches stomach walls • This stimulates stomach to make the hormone Gastrin • Gastrin stimulates more Gastric Juice and contractions • When stretched to a point, Brain perceives “fullness” Stomach • Protein, Caffeine and Alcohol stimulate walls of stomach to release more Gastrin • Stomach feels more acidic after consuming them 4. Stomach • Stomach converts food into White Paste Acid Chyme • Chyme exits through Pyloric Sphincter Stomach Problems • Ulcer – Erosion of protective mucus – Acid eats through lining – Get hole – Helicobacter pylori Stomach Ache Abdominal adhesions Abdominal aortic aneurysm Appendicitis Biliary Cholic Bladder infections Bowel obstruction Cholecystitis Colon cancer Diverticulitis Gall stones,Excessive gas Endometriosis Food allergy Food poisoning Hernia Indigestion Irritable Bowel Syndrome Kidney stones Lactose intolerance Menstrual cramping Metabolic disease Ovarian cysts Ovarian cancer Pelvic Inflammatory Disease Peritonitis Streptococcal pharyngitis Toxins Ulcers Uterine fibroids Viral gastroenteritis Psychological factors 5. Small Intestine Over 20 Feet Sections: 1. Duodenum 2. Jejunum 3. Ileum Duodenum • Mixing site of Chyme and Bile • HCl causes for Bicarbonate (basic) to come from pancreas • High pH (8) • Chyme causes for Gastrin production to stop Duodenum • Bile (made by liver), stored in Gallbladder • Injected in Duodenum through the common bile duct • Bile (not an enzyme) emulsifies fats Gallstone Problem Hardened Cholesterol Deposits, block bile exit Duodenum • Chyme mixes with Pancreatic Juice injected by the Pancreas through Pancreatic Duct Pancreatic Juice/Intestinal Juice •Amylase •Trypsin and Chymotrypsin •Nucleases •Lipases •Maltase, Sucrase, Lactase… •Aminopeptidase, •Carboxypeptidases Small Intestine Lining • Villus=Fingerlike projection extending into tube lumen – Capillaries absorb monosaccharides, amino acids – Lacteals absorb glycerol and fatty acids • Small intestine pulled out has surface area of a tennis court Small Intestine Lining Even more absorption surface! Jejunum/Ileum • Absorption of nutrients Appendix Vestigial Organ Prone to Infection and inflammation (Appendicitis) Long in Herbivores Very short in Carnivores Short in Omnivores 6. Large Intestine 6. Large Intestine (Colon) • Not as long as small intestine! • 90% of water reabsorbed before elimination • Forms Feces=Fiber, water, bile salts, mucus • Have colony of E. coli bacteria that produce Vit. K (Antibiotics kill them) Large Intestine Problems • Diarrhea= Feces moves out too quickly for water reabsorption • Constipation=Feces hangs around too long and we overly dry it • Flatulence=Poorly digested food in large intestine, bacteria digest it, produce H2S and methane gas • IBS=Probable nerve association 7. Rectum • Store Feces • Flow controlled by rectal sphincters • Then out anus Ruminant Animals • 4 chambered stomach • In Reticulum are bacteria and protozoa that can breakdown cellulose • Regurgitate food • Chew Chud and re-swallow • Ex. Cow, sheep, deer, goat What about horses, rabbits and elephants? • They have bacteria in a cecum • Too far to regurgitate • They make much more poop compared to Ruminants • Rabbits eat their feces for another shot!