Digestive Sysem Flashcards
gastric juice
breaks apart the cells in food
3 types of cells secreted by gastric glands
- ) mucous cells
- ) chief cells
- ) parietal cells
mucous cells
secretes mucous to protect stomach and cells from the acids and enzymes released during digestion
chief cells
secretes pepsinogen
parietal cells
secretes hydrochloric acid
pepsinogen
inactive form of pepsin
pepsin
enzyme that digests proteins
how do HCl and pepsin interact in the stomach?
- ) pepsinogen and HCl are secreted into the lumen of the stomach
- ) HCl converts pepsinogen into pepsin
- ) Pepsin activates more pepsinogen (chain reaction)
- ) The pepsin begins chemical digestion of proteins
lumen
cavity
gastrin
stimulates secretion of gastric juice
4 steps of food processing
- ) ingestion
- ) digestion
- ) absorption
- ) elimination
4 types of feeders
- ) suspension feeders
- ) substrate feeders
- ) fluid feeders
- ) bulk eaters
Fluid feeders
Take nutrient rich fluid from living host
Example: parasite
Suspension feeders
Take water in and filter out organisms to eat
Example: whale, clam
Bulk eaters
Eat large meals and processes them over a period of time
Example: Python
Alimentary canal
Runs from mouth to anus
Digestion
Enzymatic hydrolysis
Enzymes: catalyze/speed up chemical reactions
Hydro: water
Lysis: to break apart
Mechanical digestion (in oral cavity)
Teeth grind apart food
Chemical digestion (in oral cavity)
Saliva breaks down food in mouth
Amylase
Breaks down carbohydrates
Mucin
Creates a protective barrier (so epithelial cells are not harmed) and moistens food to make digestion easier
Tongue
Tells stomach what to digest
Trachea
Leads to respiratory system (lungs)
Epiglottis
Covers trachea to prevent food from entering the lungs and pushes food down the esophagus
Esophagus
Leads tithe digestive system (stomach)
Peristalsis
Contraction of smooth muscles
Duodenum
Beginning of the small intestine
Pancreas
Releases bicarbonate and proteases
What do bicarbonate a released by the pancreas do?
Neutralize chyme
What do the proteases released by the proteases do?
Digests proteins
Liver
Creates bile
Gallbladder
Stores bile
What happens when chyme comes on contact with bile?
The bile digest the lipids in the chyme
Where do fats enter the body instead of the blood?
Lymphatic system
Where and how are nutrients (NOT FAT) transported?
Nutrients is transported from the small intestine into the blood stream by active transport or diffusion
Lacteals leads to ______.
Lymph vessels
Capillaries lead to ____?
Blood vessels
When does osmosis occur in food processing?
Between large Intestine and outer blood vessels to transport water out of the alimentary canal into the blood.
Lumen
Inner space
Epithelium
Outer space
Rectum
Where stool is stored until it can be eliminated
Secretin
Stimulates pancreas to release sodium bicarbonate to neutralize the chyme
Amino acids (fatty acids)
Trigger the release of CCK to stimulate release of enzymes from pancreas and bile from the gallbladder
