HNF 461 1st Edition Lecture 11 Outline of Last Lecture I Direct Calorimetry II Indirect Calorimetry a Respiration Quotient III Doubly Labeled Water IV Body Weight Regulation V BMR VI Estimated Energy Requirement EER Outline of Current Lecture I Functions of the GI Tract II Layers of the GI Tract III Oral Cavity IV Swallowing V Stomach a Cell Types VI Small Intestine VII Movement of Food through the Intestines VIII Large Intestine Colon IX Tight Junctions X GI Disorders a GERD b Celiac s Disease c Pancreatitis Current Lecture Assessing Energy Expenditure 1 Functions of the GI Tract a Digestion Breakdown from macro to micronutrients These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 2 3 4 5 b Absorption Taking in of smaller pieces into the blood lymphatic systems c Secretion Ex production of bile d Storage Two sites i Stomach Holds food ii Large Intestine Storage of feces e Excretion GI Tract has no borders food air can enter into the body freely Composed of 4 layers a Mucosa innermost layer composed of 3 sub layers i Epithelial Absorptive and specialized ells 1 Exocrine Cells release outside of the body 2 Endocrine Cells release inside of the body ii Lamina Propria made of connective tissue holds things together lymphatic tissue and blood vessels transport through body iii Muscularis Mucosa b Submucosa c Muscularis Externa responsible for movement of stomach intestines Composed of 2 sub layers that controls movement in 2 directions i Circular Muscle ii Longitudinal Muscle d Serosa outermost layer Oral Cavity a Lips help to take food liquid in b Teeth grind large pieces of food into smaller pieces physical breakdown of food c Tongue holds food in correct position d Salivary Glands 3 sets make saliva which contains enzyme and antibacterial components i Enzymes Salivary amylase digests carbohydrates starch into glucose lingual lipase digests monoglycerides and triglycerides into free fatty acids ii Antibacterial compounds help to kill bacteria Swallowing a Chewing and initiation of swallowing are voluntary processes b Once food is in esophagus becomes an involuntary process c Epiglottis closes off airway before swallowing to food does not go into air pipe Stomach a Muscular structure moves and grinds food b Controls movement and release of food into the small intestine gradually c Produces gastric acid pH 2 d Various cells within the gastric pit secrete different enzymes and hormones i Chief Cells secrete pepsinogen and gastric lipase ii Neck cells secrete mucus iii Parietal Cells secrete H and intrinsic factor iv G Cells secrete gastrin e Carbohydrate digestion does not occur in the stomach but partial fat digestion does occur f Mucous in the stomach provides a medium for excretion of enzymes into the stomach and protects the stomach lining from acidic digestive juices 6 Small Intestine a Three sections duodenum jejunum and ileum b Combination of food pancreatic juice and bile for digestion i Pancreatic juice released by pancreas pancreatic amylase contains enzyme to digest macronutrients ii Bile released from gallbladder c Villi of the small intestine contain blood vessels that are responsible for taking away nutrients to other parts of the body increase surface area for efficient absorption 7 Movement of Food through Intestines a Segmentation muscle contractions of circular muscles Creates chopping motion b Peristalsis muscle contractions of circular and longitudinal muscles Propels food forward 8 Large Intestine Colon a Ascending Transverse and Descending Colon b Minimal digestion occurs in large intestine Mostly removes water from remnants of food c Bacteria in colon help with breakdown of some nutrients and can produce vitamin K 9 Tight Junctions a Complex structure composed of proteins b Forms a seal to tightly connect adjacent cells to prevent leakage i Keeps good bacteria in and keeps bad bacteria out 10 GI Disorders a GERD Heart Burn acid reflux causes burning sensation because esophagus is not protected from gastric acid b Celiac Diease Autoimmune disorder to gluten c Chronic Pancreatitis Inflammation of the pancreas influence the production of pancreatic juice Digestion can be impacted if not enough enzymes are being produced
View Full Document
Unlocking...