Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

Anatomy:Anatomy:

Mouth (oral cavity)Mouth (oral cavity)

teeth, tongue, salivary glandsteeth, tongue, salivary glands

ThroatThroat

pharynx, epiglottis (pharynx, epiglottis ( part of the part of the larynx that closes off the larynx that closes off the

trachea to trachea to lungs)lungs)

Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

Anatomy: Anatomy: Mouth Mouth

ThroatThroat

Esophagus = tube that connects Esophagus = tube that connects pharynx to the stomach (about 10 in.)pharynx to the stomach (about 10 in.)

StomachStomach

Small intestineSmall intestine

large intestine, colonlarge intestine, colon

rectumrectum

anusanus

Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

ingestion= food entering the mouthingestion= food entering the mouth

chewing=mastication or crushing foodchewing=mastication or crushing food

digestion = chemical breakdown of foodsdigestion = chemical breakdown of foods

secretion = acids, buffers, enzymes and secretion = acids, buffers, enzymes and H2O H2O aids in breakdown of foodaids in breakdown of food

absorption = broken down food is absorbed absorption = broken down food is absorbed into the blood stream and lymph systeminto the blood stream and lymph system

excretion = waste products are eliminated excretion = waste products are eliminated from the bodyfrom the body

Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

Oral cavityOral cavity

Teeth: enamel-hardest substance in Teeth: enamel-hardest substance in the the bodybody

20 baby (deciduous) & 32 adult 20 baby (deciduous) & 32 adult w/wisdom, 8 Incisors, 4 cuspid, 8 w/wisdom, 8 Incisors, 4 cuspid, 8 premolars & 12 molars (3premolars & 12 molars (3rdrd molar molar wisdom)wisdom)

tongue (aids in mastication)tongue (aids in mastication)

salivary glands – 3 pairssalivary glands – 3 pairs

Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

Stomachlocated on the left side of abdominal cavity, under the diaphragm and covered almost completely by the liver

approximately 10 inches long, diameter varies depending on the amount ingested, can expand due to folds

temporary holding area for food, secrets gastric acid & enzymes

Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

Stomach

Regulates the rate, partially digested

food enters the small intestine

absorbs small amounts of water and other substances-very limited

takes about 4 hours to empty after a meal

liquids and carbohydrates pass through quickly, protein a little more time, fats take the longest

Digestive system Digestive system (gastrointestinal, GI tract)(gastrointestinal, GI tract)

Pyloric sphincter

Duodenum- first section in the small intestine 10-12 inches long

Jejunum- middle section in the small intestine 8ft

Ileum-last section 6-12 ft long, attaches to the large intestine