BSC 109 1st Edition Lecture 20 Outline of Last Lecture I. The endocrine system produces hormonesII. Hormones are classified as steroid and nonsteroidIII. The hypothalamus and the pituitary glandIV. The pancreas secretes glucagon, insulin, and somatostatinV. The adrenal medulla: epinephrine and norepinephrineVI. Thyroid and parathyroid glandsVII. Iodine deficiency can cause goiterVIII. Important hormonesIX. Disorders of the endocrine systemOutline of Current Lecture I. The digestive system brings nutrients into the bodyII. 5 basic processes accomplish digestive system functionIII. 2 types of motility aid digestive processesIV. the pharynx and esophagus deliver food to the stomachV. the stomach stores food, digests protein, and regulates deliveryVI. gastric juice breaks down proteinsVII. The small intestine digests food and absorbs nutrients and waterVIII. accessory organs aid digestion and absorptionIX. the large intestine absorbs nutrients and eliminates wastesX. how nutrients are absorbedXI. endocrine and nervous systems regulate digestionXII. nutrients are used or stored until neededCurrent LectureXIII. The digestive system brings nutrients into the bodyA. Gastrointestinal tract1. Lumen: space within this tube2. Includes mouth, pharynx, esophagus, stomach, small intestine, large intestine (colon), rectum, anusB. Accessory organs: salivary glands, liver, gallbladder, pancreasXIV. 5 basic processes accomplish digestive system functionA. mechanical processing and movement: includes chewing and mixingB. secretion of the following:1. fluidThese 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. digestive enzymes and hormones3. bile, acid, alkali, mucusC. digestion1. breaking down food to smallest absorbable units2. includes chemical and mechanical breakdownD. absorption1. occurs through mucosa2. nutrients and water move into blood or lymph vesselsE. elimination: undigested material is eliminated as fecesXV. 2 types of motility aid digestive processesA. peristalsis: propels food forwardB. segmentation: mixes foodC. teeth: bite and chew foodD. tongue: positions and tastes foodE. saliva1. secreted by salivary glands2. composition of salivaa) mucinb) salivary amylase: begins digestion of starchc) bicarbonate: maintains pH (6.5-7.5) for optimal amylase activityd) lysozyme: inhibits bacterial growthXVI. the pharynx and esophagus deliver food to the stomachA. swallowing1. voluntary phase: tongue pushes bolus of food into pharynx (throat)2. involuntary phase: swallowing reflexB. pharynx: common passageway for air and foodC. epiglottis: closes airway temporarily so food will not enter the tracheaD. food moves through to the esophagus with the help of peristaltic contractionsE. food passes through lower esophageal sphincter into the stomachXVII. the stomach stores food, digests protein, and regulates deliveryA. food storageB. digestion of proteinsC. regulation of delivery of partially digested food into the small intestineXVIII. gastric juice breaks down proteinsA. hydrochloric acid: produces a pH of about 2; breaks down large bits of foodB. intrinsic factor: made by same cells that make acid; needed to absorb vitamin B12C. mucus: protects stomach lining from acidD. pepsinogen: converted to pepsin by acid; begins protein breakdownE. Required 2-6 hours for stomach to empty completely after a mealXIX. The small intestine digests food and absorbs nutrients and waterA. Small intestine functions in digestionB. It breaks down proteins, carbohydrates, and lipids to absorbable materials (monomers)C. 90% of food is absorbed in small intestineD. Large surface area1. villi: microscopic projections containing blood and lacteal capillaries2. microvilli: cytoplasmic projections of epithelial cells of the villiXX. accessory organs aid digestion and absorptionA. pancreas: digestive enzymes include proteases, pancreatic amylase, lipaseB. liver: produces bile, which emulsifies lipidsC. gallbladder: concentrates and stores bileXXI. the larege intestine absorbs nutrients and eliminates wastesA. functions1. absorbs nutrients and water2. temporarily stores and eliminates wasteB. structure1. colon: ascending, transverse, descending, sigmoid2. rectum, anusXXII. how nutrients are absorbedA. amino acids: breakdown products of proteins are absorbed by active transportB. monosaccharides: breakdown of products of carbohydrates; are absorbed by active transportC. lipids: broken down to monoglycerides and fatty acids, absorbed, and reassembled into triglycerides within epithelial cellsD. water: absorbed by osmosisE. vitamins and minerals absorbed via assorted meansXXIII. endocrine and nervous systems regulate digestionA. regulation dependent on volume and nutrient content of foodB. nervous system: stretch receptors in stomach: reflexes increase peristalsis and secretion of gastric juiceXXIV. nutrients are used or stored until neededA. excess energy-containing nutrients may be stored, increasing body weightB. storage forms can provide energy when we consume fewer energy-containing nutrients than we needC. eat slower, water first, salad appetizerD. carbohydrates: a major energy source1. simple carbs: sugars2. complex carbs: starch, glycogen, fiberE. lipids: essential cell components and energy sources1. saturated fatsa) meat, dairy products, palm kernel oilb) tend to raise LDL cholesterol2. unsaturated fatsa) plant sources, olive, safflower, corn, canola oilsb) certain cold water fish (omega-3 fatty acids)c) tend to lower LDL cholesterold) linked to reduced risk of heart disease3. trans fatsa) produced by hydrogenation of vegetable oilsb) raise LDL cholesterolF. complete proteins contain every amino acid1. 20 different amino acidsa) 12 can be made by the human bodyb) 8 essential amino acids must be ingested in foods2. complete proteins: contain all 20 amino acidsa) most animal proteinsb) soy protein3. incomplete proteins: lack one or more essential amino acids (many plant proteins are incomplete)G. vitamins are essential for normal function (2 groups)1. Fat soluble: absorbed with fats and stored in adipose tissue2. Water soluble: stored only briefly; must be consumed on a regular basisH. Minerals are essential elements for body processes1. Ions in blood plasma and cell cytoplasm2. Chemical structure of bone3. Nerve and muscle activityI. Fiber benefits the colon1. Problems with a low fiber diet: 2. Contributes to chronic