NTDT200 019 Chapter 3 Digestion Absorption and Transport 09 10 2013 Mouth Esophagus Stomach Small Intestine Large Intestine Rectum Anus Gastronintestinal Tract GI flexible and muscular Lumen continuous Look over the diagram on the powerpoint of each part of digestion Starts Mouth four basic taste sensations 1 1st part is chewing salvia is an enzyme to help break down the food teeth rip and grind the food to smaller pieces 2 taste buds sour sweet bitter salty savory umami 3 pharynx pushes food down esophagus 4 food now called bolus Esophagus 1 two sphincters upper and lower esophagus sphincters Stomach 2 movement of bolus mixes to become a liquid 3 liquid is called chyme 4 pyloric sphincter Small Intestine 1 three segments duodenum jejunum ileum 2 Nutrient is extracted and absorbed Large Intestine 1 Lleocecal valve 2 Ends with the colon water is extracted 3 Muscles in the rectum and the anus Peristalsis in rectum stomach small intestine 1 Segmentation different types of muscles 2 Sphincter contracts and periodically opens and closes controls pace of the GI tract contents 3 Squeeze and then Release 4 Circular and longitudinal muscles 5 Medication and medical conditions can get in the way of peristalsis Secretions 1 Salivary glands stomach pancreas liver small intestine secrete enzymes and water 2 Enzymes are facilitators of chemical reactions proteins Salvia protective role lines the mouth starts the digestion of carbs Gastric Juice from stomach made up of water enzymes and hydrochloric acids used for protein digestion Pancreatic Juice released in the duodenum acts on carbs protein and fats contains sodium bicarbonate to help nuetralize the acid Bile in the liver and gallbladder not an enzyme but an emulsivifier Summary of digestive secretions and their actions figure Final stage Colon 1 Intestinal bacteria good and bad 2 Recyclable materials water and dissolved salts Fiber not digested at all until excretion crabs digested in stomach quickly and small intestine absorbed protein digestion starts in the stomach and in small intestine absorbed fat is digested slightly in the stomach but mainly in the small intestine absorbed Small intestine is 10 ft long Three types of absorption 1 Simple diffusion 2 Facilitated diffusion requires a carrier 3 Active Transport uses ATP against concentration gradient things with calories needs a carrier and releases calories energies Villi select and regulate nutrients absorbed inside of the small intestine little hairs pushes food down Microvilli enzymes and pumps Crypts secretion of intestinal juices Goblet Cells mucus secretion on villi too Villi cells regulate nutrient absorption based on needs Food combining Enhances use in the body such as eating red meat by itself or just eating fruit the body doesn t care it takes and uses what it needs and then absorbs and saves the rest Transport Pathways 1 Bloodstreams water soluble nutrients and smaller products of fat digestion 2 Lymphatic system fats Vascular system closed system of vesicles blood delivers oxygen and nutrients blood removes carbon dioxide and waste special routing for the digestion system liver is like a chemical factory heart is the pump Liver water soluble nutrients go right to the liver while fat soluble goes to the heart and then comes to the liver later you can function with only 20 of the liver detoxic diets cleanse the liver even though the body does it for you Lymphatic System no pump circulation btwn cells enters bloodstream through sublcavion veins nutrients in lymphatic vessels bypass the liver at first Health and Regulation 1 Most bacteria in GI are not harmful 2 Factors that influence bacteria presence probiotics used for constipation and immune health and prebiotics 3 Probiotics found in food that is fermented such as pickles some Korean foods misu soup sourcrout YOGURTS 4 Prebiotics found in foods and proteins not digested like yogurt found in the bacteria 5 Some of the new studies are about red meat and bacteria measure bacteria in meat eaters and then vegetarians and vegans one type of bacteria linked to heart disease 6 People who ate less meat had lower levels of bacteria study Homeostatic regulation balanced and even 1 Endocrine system provide hormones chemical messengers with a response 2 Nervous system 3 Feedback mechanisms when the body does something like you eat food and then you get a certain response to that example getting cold so your body gets goose bumps to warm you up or when you are sick you throw up negative and positive feedback loops 4 Three hormones Gastrin Stomach wall Secretin duodenal wall Cholecystokinin CCK intestinal wall Common Digestive Problems 1 Diarrhea medical conditions such as irritable bowel syndrome IBS women 30 times more likely to get than men don t eat high fat foods or fried foods as much Two types diarrhea and constipation Treatments just keep a food log and see what foods cause stomach aches or problems such as stress anxiety or food allergies some medications but may not work really well Causes unknown what you eat Colitis inflammation of large intestines Chromes patchy areas in the colon that don t absorb nutrients could be genetic low fiber and residue very painful and symptoms are stomach aches and bloody waste 2 Celiac Disease one and 112 people have celiac auto immune disease may not have physical symptoms but fatigue may occur causes malnutrition May do a biopsy and with celiac disease the sample is smooth not bumpy meaning not absorbing the right nutrients Leads to weight loss or ostesporosis Only treatment Do not eat glutten if you eat it you make get joint pain memory loss hair loss fatigue weight loss painful stomach aches and diarrhea Huge celiac center at university of Maryland Could be a silent celiac disease with only symptoms such as fatigue Could brown almost all food glutten free nowadays such as glutten free cookies cake mixes and pizzas Gluttten free diet should not cause weight loss and sometimes glutten free food actually has more calories This could lead to increase in cholesterol and weight 3 Constipation not a disease caused by slow moving digestion lack of fiber and fluid and lack of exercise could buy miralax or benefiber some people are more prone to constipation 4 Intestinal Gas Consumption of certain foods individually determines could be caused by eating foods with insoluble or fake fibers broccoli and beans 5 Gastroesophageal reflux heartburn Could take medication watch how much spicy foods you eat
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