Transcript Digestive System

Digestive System
Anatomy and Physiology Lab II
General Functions/Info
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Breaks down food mechanically/chemically
Absorbs nutrients
Gets rid of waste through feces
9 meters long/hollow tube, mouth to anus
Three accessory organs; 1. pancreas, 2. gall
bladder, 3. liver
Mouth/Esophagus
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Two types of digestion
Mechanical- chewing
Chemical- carbohydrate digestion,
saliva>>>amylase>>>disaccharides
Esophagus- muscular tube connecting pharynx
to stomach
Peristalsis
Stomach
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Large J-shaped organ
Rugae- in folds, allows expansion, hides gastric pits
Mucus layer- every two days
Two types of digestion
Mechanical- churning/mixing
Chemical- HCl>>> pepsinogen>>>pepsin>>breaks
down proteins to amino acids
Bolus-ball of food
Chyme- soupy mixture from bolus , pH1
Stomach cont.
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Diaphragm divides abdominal/chest cavities
Esophageal hiatus- hole with through sphincter
ring, prevents backflow, regulates how much is
dumped into stomach
4 parts of stomach, most important pyloric
region, containing pyloric sphincter regulating
flow of chyme to small intestine
Small Intestine
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15ft long, 1 inch in diameter
Omentum- outer covering keeps in bag
Three parts; digestion in the 1st, nutrient
absorption in 2nd and 3rd
Duodenum- 10 inches, receives chyme from the
stomach, entrance point for accessory organs
Accessory Organs
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1. Liver: produces bile, involved in fatty food
digestion, regulates pH of chyme coming into
small intestine, pH 8-9
2. Gall Bladder: bag for extra bile
3. Pancreas: secretes enzymes; lipases, proteases,
carbohydrases
Small Intestine cont.
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Jejunum- 8ft long, majority of nutrient
absorption
Ileum- Ends at ileocecal valve, controls flow of
materials from ileum into the cecum of large
intestine
Intestinal wall contains many microvilli which
aid in absorption
Large Intestine
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Gets rid of waste, water absorption
5 feet long, 2 inches in diameter
Cecum, lower right quadrant, compaction
begins, contains appendix
Ascending colon
Transverse colon
Descending colon
Sigmoid- S Shaped
Large Intestine cont.
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Rectum- holding area for feces
Internal/External anal sphincters
Only have control of external
Mucus producing cells
Anus
To much water diahhrea, not enough
constipation