Digestive System

Digestive System 3 main functions 2 main divisions Digestion Absorption Elimination 2 main divisions Alimentary canal Tube from mouth to anus Accessory organs Aid in digestion

Digestive System Elimination Digestion Process of breaking down food into molecules the body can absorb. Absorption Process of molecules passing from the alimentary canal to blood stream. Elimination Process of the body getting rid of unabsorbed solids and liquids Feces Urine

Alimentary Canal Tube from mouth to anus Mouth / oral cavity Ingestion Putting food in your mouth Mastication Chewing Bolus Mass of chewed food

Alimentary Canal Throat / Pharynx Connects mouth to esophagus 3 sections Nasopharynx Oropharynx laryngopharynx Deglutition swallowing

Alimentary Canal Esophagus Connects throat to the stomach Peristalsis Epiglottis Covers the trachea during swallowing Peristalsis Contraction of smooth muscle to move food through digestive tract.

Alimentary Canal Stomach Sac like organ Digestion continues Bolus mixes with gastric juices… Hydrochloric acid Pepsin Chyme Soupy mass of food and gastric juices Digestion continues Absorption begins

Alimentary Canal Small intestine Connects stomach to the large intestine 3 main parts Duodenum Jejunum Ileum Most nutrient absorption occurs here. Fat is broken down by bile.

Alimentary Canal Large intestine 3 main sections Cecum Colon Rectum Anus Opening to the rectum Elimination occurs here

Accessory Organs All the organs that aid in the digestive process. Teeth Salivary glands Saliva Tongue Muscles Liver Pancreas

Accessory Organs Teeth Incisors – cut Cuspids – tear Premolars – chew Molars – grind, chew Chewing mastication Mechanical break down of food.

Accessory Organs Saliva glands Saliva 3 pair Produce saliva Parotid Sublingual Submandibular Produce saliva Saliva Lubricates food Enzyme Salivary amylase Chemically breaks down food

Accessory Organs Tongue (glossus muscle) Muscles Moves and holds food between teeth. Moves food (bolus) towards throat. Muscles Mastication = chewing Deglutition = swallowing Paristalsis = contraction of smooth muscle

Accessory Organs Liver Produces bile Breaks down fat for absorption Stored in the gallbladder Yellowish-green alkaline fluid Found in small intestine

Accessory Organs Pancreas Produces and secretes pancreatic juices containing digestive enzymes Empty into small intestine Completes the breakdown of carbohydrates

Conclusion Understanding the digestive is very important. Teeth are organs of the digestive system, and tooth decay (caries) is a disease of the digestive system. Any questions??