Question | Answer |
Alimentary Canal | oLong muscular tube
oBegins at the mouth and ends at the anus
oAccessory organs salivary glands, tongue, teeth, liver, gallbladder, and pancreas |
Mouth, Buccal, Oral Cavity | oFunction
receives food as it enters the body |
Digestive System | Also known as the GI system (gastrointestinal)
Physical and chemical breakdown of food for use by body
Alimentary canal and the accessory organs |
Actions in the mouth | Tasted
Broken down physically by teeth
Lubricated
Partially digested by saliva
Swallowed |
Teeth | physically broken down |
Tongue | contains special taste receptors; aids in chewing and swallowing food |
Taste Buds | Sweet & Salty(tip); Sour & Bitter |
Hard Palate | bony structure = roof of mouth; separates mouth from nasal cavities |
Soft Palate | behind hard palate; separates mouth from nasopharynx |
Uvula | muscular structure that hands from middle of soft palate = prevents food from entering nasopharynx |
Mastication | chewing |
Salivary Glands | (3 pairs = parotid, sublingual, submandibular)
oFunction of saliva
lubricates during speech and chewing, moistens food and contains enzymes (speed up chemical reactions) |
Salivary Amylase | breakdown of carbs (starches) into sugars |
Bolus | food that has been chewed and mixed with saliva |
Esophagus | muscular tube dorsal to trachea
Carries bolus to stomach
Peristalsis moves food toward stomach |
Stomach | (blank) |
Cardiac Sphincter | circular muscle between esophagus and stomach; close after food enters stomach; prevents food from going back up |
Pyloric Sphincter | circular muscle between stomach and small intestine; keeps food in stomach until ready to enter small intestine |
Chyme | food in converted into a semi-fluid material called chime |
Gastric Juices | Hydrochloric acid kills bacteria, facilitates absorption, activates pepsin
Enzymes |
Hydrochloric Acid | kills bacteria, facilitates absorption, activates pepsin |
Enzymes | •Lipase
•Pepsin
•Rennin |
Lipase | starts chemical breakdown of fat |
Pepsin | protein |
Rennin | milk digestion aid for infants, not present in adults |
Small Intestine | oAbout 20 feet long; 1 inch in diameter
oReceives food from stomach in form of chyme
o3 sections |
Duodenum | first 9-10 inches
•Bile enters through ducts of gallbladder and liver and pancreatic juice also via ducts/tubes |
Jejunum | 8 feet; middle section |
Ileum | final 12 feet
•Connects to large intestine at cecum |
Functions of small intestine | Digestion is completed
•Products of digestion absorbed into blood stream for use of cells
•Intestinal juices produced (by small intestine) contain enzymes that breakdown sugars into simpler forms |
Intestinal Juices | complete protein, sugar, and fat digestion |
Bile | emulsifies (physically breaks down) fat |
Villi | lines small intestine; fingerlike projections; capillaries absorb digested nutrients and carry them to the liver; where they are stores or released for use of body cells |
Pancreatic Juice | complete digestion process |
Large Intestine | o About 5 feet long; 2 inches in diameter |
Large Intestine Funcitons: | Absorption of waterAbsorption of any remaining nutrientsStorage of indigestible materials before elimination from bodySynthesis (formation) and absorption of B-complex vitamins and vitamin K by bacteria present in intestine
Transportation of waste |
Cecum | first section; connected to ileum (small intestine) |
Ascending Colon | up on right side of body from cecum to lower part of liver |
Transverse Colon | extends across abdomen |
Descending Colon | extends down left side of body; connects with sigmoid |
Sigmoid Colon | s-shaped; joins rectum |
Rectum | 6-8 inches; storage area for indigestibles and waste |
Anal Canal | opens at a hole = anus |
Anus | opening; digestive waste is expelled through this opening |
Vermiform Appendix | small projection |
Liver | oLargest gland in the body
oAccessory organ for digestive system
oLocation: under diaphragm and in upper right quadrant of abdomen |
Liver Functions (1) | Secretes bile; emulsifies fats; water soluble necessary for absorption
Stores sugar in form of glycogen; released later as needed
Stores iron and certain vitamins
Produces heparin; prevents clotting of blood
Produces cholesterol |
Gallbladder | oSmall muscular sac
oLocation: under liver, attached by connective tissue
oStores and concentrates bile
oBile needed to emulsify fats |
Pancreas | oFish-shaped organ located behind the stomach
oProduces pancreatic juices to digest food
oProduces insulin which is secreted into the blood stream; regulates burning of carbohydrates to convert glucose into energy |
Liver Functions (2) | Detoxifies substances; alcohol, pesticides
Destroys bacteria in blood (taken in from intestine) |