Transcript Digestive system

Digestive system
(gastrointestinal, GI tract)
Anatomy:
Mouth (oral cavity)
teeth, tongue, salivary glands
Throat
pharynx, epiglottis ( part of the
larynx that closes off the trachea to
lungs)
Digestive system
(gastrointestinal, GI tract)
Anatomy:
Mouth
Throat
Esophagus = tube that connects pharynx
to the stomach (about 10 in.)
Stomach
Small intestine
large intestine, colon
rectum
anus
Digestive system
(gastrointestinal, GI tract)
ingestion= food entering the mouth
chewing=mastication or crushing food
digestion = chemical breakdown of foods
secretion = acids, buffers, enzymes and H2O
aids in breakdown of food
absorption = broken down food is absorbed into
the blood stream and lymph system
excretion = waste products are eliminated from
the body
Digestive system
(gastrointestinal, GI tract)
Oral cavity
Teeth: enamel-hardest substance in the
body
20 baby (deciduous) & 32 adult
w/wisdom, 8 Incisors, 4 cuspid, 8
premolars & 12 molars (3rd molar
wisdom)
tongue (aids in mastication)
salivary glands – 3 pairs
Digestive system
(gastrointestinal, GI tract)
Stomach
located 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
(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
(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