Digestive System U4 Flashcards
Digestion
Physical and chemical processes that reduce food to small molecules to be absorbed
Absortion
Entrance of molecules along the gut lining
Elimination
Components exit the body (defication)
Chemical Digestion
Chemicals break down of food
Physical Digestion
Physical breakdown of food (increases surface are so enzymes can work)
Oral Cavity; Lips; Teeth; Salivary Glands
- (Mouth) storage place for food while being chewed
- Hold food in oral cavity, and guide to teeth
- Physical Digestion
- Produce saliva for moistening and chemically digesting food(contains salivary amylase)
Tongue; Pharynx; Epiglottis; Esophagus
- Directs food onto teeth and pushes chewed food to pharynx
- Where oral and nasal cavity joins at back of throat
- Flap at base of tongue; keeps food from going down windpipe (trachea)
- Tube leading from pharynx to stomach
Swallowing; Peristalsis
- Relax action (typically automatic) food enters the esophagus
- Rhythmical contraction of esophageal wall, pushes food along
Cardiac Sphincter; Stomach
- Band of muscles that close of top of stomach (prevents regurgitation)
- J-shaped organ, stores and churns food, helps physically digest food (mushy liquid call acid chyme)
Gastrin
- Hormone produced by the lower stomach, enters the bloodstream and stimulates
upper stomach to stimulate gastric glands
Gastric Glands; Pepsin
Produce HCI and Pepsinogen, which react to produce Pepsin
-Chemically Digest proteins to peptides
(HCL can burn gut lining which is why there’s a mucus layer)
Pyloric Sphincter; Duodenum; Pancreas
- Band of muscles that close of lower stomach (only allows 1 teaspoon of chyme to enter small intestine)
- First 10 inches of small intestine; enzymes from pancreas and small intestine digest all three food groups here (bile also secreted to emulsify fats)
- Produces enzymes and sodium bicarbonate (sodium bicarb need to neutralize acid chyme bring from pH of 2 to pH of 8.5
Gall Bladder; Liver; Small intestine
- Stores Bile, which is secreted into small intestine
- Produces Bile (emulsify fats stored in gall bladder)
- Final digestion and absorption of nutrients through Villi
Scretin and CCK
Produced by duodenal wall in response to acidic chyme
- stimulates release of pancreatic juice
- stimulates release of Bile
Absorption in Small intestine
long convoluted walls (folded); walls have villi ; villi have small microvilli
Each villius has blood vessels and small lymph vessel called lacteal