L5 - Human Digestive System PDF

earming Outcomes  The digestive system uses to process nutrients (food) in the following ways : many organs &g...

earming Outcomes  The digestive system uses to process nutrients (food) in the following ways : many organs &g a on · movement of and of taking of uptake brea substances use food drink into nutrients into blood nutrients by cells body F u proteins lipids carbohydrates Absorption nation. The organs of the digestive system fall into I groups : removal of undigested #estionI - canal running through body food faces Alimentary tube : as in which food passes mouth anus wo Associated organs : aid in process of digestion -mouth ingestion oral physical digestion cavity of food also digestion : , of food using teeth S i) salivary glands produces amylase we and secretes saliva which to break down starch contains : sa of carbs using enzymes liquid to lubricate food and make pieces stick chemical digestion together forming a bolus tongue I food around and helps swallow oesophagus I F · moves & · also responsible for detecting taste transfers bolus from mouth to stomach by peristalsis epiglottis # flap which closes windpipe stomach which contains : during ingestion to prevent · produces gastric juice food entering airway pepsin to break down proteins hydrochloric acid HClags to kill bacteria · muscles churn bolus into liquid : chyme wo liver · makes bile containing emulsify fats salts which pancreas we · assimilates digested food (glucose Secretes · pancreatic juice into duodenum via pancreatic duct which contains : amylase for breakdown of starch bladder wo gall trypsin for breakdown of proteins stores and secretes bile S lipase for breakdown of lipids D via bile duct into duodenum · also neutralizes acid from stomach & i -small intestine - large intestine i duodenum & color & I water is absorbed from food stomach to rest undigested · · connects of small intestine · bile salts absorbed and returned to liver · site where pancreatic enzymes > · bacteria break down food C and bile are secreted and act rectum ileum -stores faces · enzymes on epithelial lining further digest carbohydrates, Lans( proteins and fats controls the egestion of faces · broken down biomolecules and water absorbed villi are by into the bloodstream and lymph · extra information Food throughout the digestive system both physically and is broken down chemically Physical digestion : the breakdown of food into smaller pieces Chemical digestion : breakdown of large insoluble molecules without chemical change to the food molecules into small soluble molecules * ⑤ ⑨g O breaking it into smaller parts enzymes catalyze the increases its surface area , facilitating · a breaking of bonds within j chemical digestion by E enzymes molecules , making them ·. small enough for absorption ↑ · Mouth ingests food · Most of physical digestion occurs in the mouth. · Teeth physically break down food into smaller parts teety as humans are omnivores (eat animal and plant material we have specialized teeth : some for tearing and some for and and cutting exicanines chewing grinding eximolars S · Chemical digestion of starch occurs in the mouth 1 lubricates food, causing 3 pairs of salivary glands secrete saliva which · , a juice 10F pieces to stick together now called a bolus) and contains the enzyme salivary amylase amylase catalyzes nur breakdown into of disaccharides starch (maltose) jim starch -mylase maltose reducing sugar S H the oesophagus propels the longitudinal muscles bolus bolus from the throat to the circular muscles stomach using a wave of ⑳ oesaphagus secretes contractions called peristalsis circular muscles contract behind : to protect it forward mucus bolus-squeezing lining and lubricate bolus longitudinal muscles contract in front of bolus , widening tube in · Stomach's walls are elastic and stretch : accommodating more food and signals muscle contraction · The Stomach's walls are composed of muscle layers which alternatively g longitudinal muscle contract and relax via peristalsis. circular muscle this of food surface physical digestion increases area and keeps it in contact with greater digestive enzymes this causes the contents to churn and mix with gastric juice becoming a creamy liquid-chyme stomach secretes gastric juice , which contains · : in Hydrochloric and acid provides , HCl acidic condition ag , which kills harmful microorganisms found optimal for in or on I bolus - which is pepsin pyloric sphincter is a value which pepsin protease is an enzyme which catalyzes chemical breakdown of proteins controls entry into into smaller polypeptide chains (peptides) and amino acids duodenum , only allowing g ELE · - liquid chyme to enter - - juice pepsin polypeptide protein amino acids and peptides  · Chyme enters the duodenum from the stomach. S Liver bile and stores it in the gall bladder where it is later · produces liver secreted into the duodenum yan bar bile contains bile salts , which help physically digest lipids through emulsification this creates smaller fat droplets , which increases surface area , facilitating enzyme action drodenum name go · · · ·* & s fat globule bile salts emulsified fat droplets The · pancreas secretes pancreatic juice into the duodenum which contains : sodium hydrogen carbonate , NaHCOs , neutralizes stomach acid for ideal alkaline condition for trypsin · pancreatic amylase : catalyzes chemical breakdown of starch into maltose trypsin protease catalyzes chemical breakdown of into smaller peptides proteins : lipase : catalyzes chemical breakdown of lipids fats oils , into fatty acids and glycerol O · O triglycerides fats and oils lipase 3 fatty acids and glycerol F on longitudinal muscle Villus : circular muscle epithelium & villus muscles contract to * propel nutrients ; , promoting movement mixing , and absorption small intestine - circulatory system - lymphatic system sugars , amino acids and salts are actively transported into epithelial cells and then diffuse into capillaries to the liver via the blood microvilli where they are transported capillary lactea ! lipids diffuse into lacteals where they are transported via the lymphatic system and eventually enter bloodstream fatty acids O water enters cells and blood via osmosis ↳ · The ileum adapted to absorption is : Glycerol W outer layer epithelium is only I cell thick very high surface area volume as the epithelium : amino acids is highly folded and each of the epithelial - villi , , peptides - many folds cells have , microvilli Nat dense network of capillaries tiny blood vessels salts Nat in each villus , allowing short distance of travel to transport lipids lacteal monosaccharides separate vessel - Once the nutrients enter the bloodstream (from capillaries or lacteals they are transported to cells in order to be used Assimilation Intel & · Mu D W Glucose Lipids Dr Amino acids - - used for cellular mainly respiration main component of cell membranes built into enzymes , membrane transporters antibodies , · , and broken down in order to produce be broken down cellular hormones , muscles structural components and more ! can during , ATP for short-term respiration for lot of not needed for cell proteins converted energy a energy proteins are built into glycogen into for later it adipose tissue glycogen in excess , is in excess , is stored in and stored use energy and stored in the liver and muscles as triglycerides for long-term use and as insulation ↑ colon food particles e · Whatever that were unable to be digested and absorbed in the small intestine enter the color-main part of large intestine - bacteria u ~ food that is indigestible is mainly due to lacking the enzyme that can break it down ex : humans lack cellulase and cannot break down cellulose in plants i.. e. fibre While the colon does not produce enzymes , it is home to trillions of bacteria which can further break down previously undigested food such as sugars which produces monosaccharides and fatty acids which can be ( absorbed but it also produces gas as a by product , i.. e flatulence fart H It appendix * The · primary function of the colon is to reabsorb water as much was used during digestion Colon absorbs bile salts returning them to the liver the blood o · via , * if the faces becomes hard a very dry , it passes more waste through moves colon via peristalsis , becoming more dry and difficultly and infrequently constipation semi-solid , becoming faces if the faces too it passes too * is watery , quickly and as a liquid diarrhea # · faces is stored in the rectum (last part of colon until a larger volume of faeces is produced · once a threshold is reach , egestion of faces is initiated : muscles more faces down the rectum via peristalsis until it reaches anus prince muscles the opening and closing of the anus is controlled by anal sphincter muscles OB... note : egestion whereas excretion = excretion. is the Egestion is the removal of waste from removal of undigested metabolism urea food faces ~mus Answer the following questions : 1 Explain two reasons why enzymes are necessary for digestion 2 a) Outline all the places physical digestion where takes place and what is occurring b) Explain the importance of physical digestion 3 Fill in the table summarizing chemical digestion : Enzyme Substrate(s) product(s) secreted by secreted into salivary amylase stomach starch pancreas g) ycero + fatty acids trypsin 4 a) Label the organs on the diagram b) indicate which organs are accessory organs 2) number the in the organs order food passes from ingestion to egestion Alimentary canal S Explain how the ileum is adapted to its function 6 If the lining of the large intestine is ruptured , this is very serious and can lead to serious illness or death. Explain why 7 Provide two benefits to the stomach's production of hydrochloric acid 8 Even though we lack enzymes to break down and assimilate cellulose (fibre) it is recommended as a regular part of diet. Explain why. 9 Contrast how carbohydrates and lipids are digested , absorbed stored , and used in the body ,