Presentation on theme: "The Digestive System Digestion Metabolism Breakdown of ingested food"— Presentation transcript:
1 The Digestive System Digestion Metabolism Breakdown of ingested food Absorption of nutrients into the bloodMetabolismProduction of cellular energy (ATP)Cellular respiration
2 Organs of the Digestive System Alimentary canali.e.: gastrointestinal (GI) tractcontinuous coiled hollow muscular tube open at both endsAccessory digestive organs
3 Organs of the Alimentary Canal MouthPharynxEsophagusStomachSmall intestineLarge intestineAnus
4 Mouth Anatomy Lips (labia) – protect Cheeks – form walls Hard palate – front roofSoft palate – back roofUvula – fleshy projectionTonsilsTongueOral cavity – area contained by the teethFigure 14.2a
5 Salivary Glands Saliva (spit) Contains enzyme amylase to begin starch digestion
6 mixes chewed food with saliva; helps us swallow the food;has papillae (bumps) that contain taste buds.
7 Functions of the Pharynx A passageway for air and foodFood is propelled to the esophagus by two muscle layersperistalsisWavelike contractions of the muscle layers
8 Esophagus Runs to stomach through the diaphragm Propels food by peristalsisPassageway for food only (respiratory system branches off after the pharynx)
9 Stomach on the left side of the abdominal cavity Food enters at the esophageal sphincterFood empties into the small intestine at the pyloric sphincter
10 Functions of the Stomach Acts as a storage tank for foodChemical breakdown of protein beginsDelivers chyme (processed food)to the small intestineSpecialized Cells of the StomachChief cells – produce protein-digesting enzymesParietal cells – produce hydrochloric acid
11 UlcersAn ulcer is an open, painful wound. Peptic ulcers are ulcers that form in the stomach or the upper part of the small intestine.
12 What causes ulcers? bacteria (Helicobacter pylori) overuse of anti-inflammatory drugs such as aspirin or ibuprofen (Motrin & Advil)SmokingDrinking alcoholUncontrolled Stress
13 Symptoms of ulcers loss of appetite sharp stomach pains Nausea and/or vomitingfrequent burping or hiccupingbloody or blackish bowel movementsweight loss
14 Small Intestine MAJOR SITE OF NUTRIENT ABSORPTION 8-18 feet long villi Fingerlike structures to increase surface areamicrovilliSmall projections of the plasma membrane
15 Large Intestine Absorption of water Larger in diameter, but shorter than the small intestineAbsorption of waterEliminates indigestible food as fecesCecum – first partAppendixColonRectumAnus – external
19 InsulinInsulin is secreted by the pancreas in response to high blood sugar (glucose).After you eat, blood glucose levels rise and in response to this, insulin is secreted into the bloodIn response to insulin, cells (muscle, red blood cells, and fat cells) take glucose in from the blood to use to generate energy (ATP)This lowers the blood glucose levels back to the normal rangeAs blood glucose falls, insulin secretion by the pancreas decreases.
20 DiabetesA person with diabetes does not produce enough insulin or produces no insulin at all.Without insulin, body cells can’t take the glucose out of the bloodBlood glucose levels become high which leads to other health problems.So, even though the blood has plenty of glucose, the cells are not getting it for their essential energy and growth requirements.Diabetes Type 1 - You produce no insulin at all.Diabetes Type 2 - You don't produce enough insulin, or your insulin is not working properly.
21 Liver Largest gland in the body Manufactures bile Bile breaks fat into smaller globs for (fat-digesting enzymes to work on.It’s connected to the gall bladder
22 Gall Bladder Small sac under the liver Connected to the liver Stores bileWhen you eat fatty foods, bile is released from the gallbladder.
23 What are gallstones? Made from cholesterol They can be as large as a golf ball.People who are overweight or who are trying to lose weight quickly are more likely to get gallstones.You can live without your gallbladder