Chapter 5: Digestive System Flashcards
The digestive or gastrointestinal system performs four main functions:
Ingestion: intake
Digestion: mechanical and chemical breakdown.
Absorption: nutrient
Elimination: defacation
Ingestion
Food material taken into mouth
Digestion
Food is broken down, mechanically and chemically, as it travels through the gastrointestinal tract.
Digestive enzymes aid the breakdown or complex nutrients.
Proteins: amino acids
Sugars: glucose
Fats: fatty acids or triglycerides
Introduction: Absorption
- Digested food passes into the bloodstream through lining cells of the small intestine.
- Nutrients travel to all cells of the body.
- Cells burn nutrients to release the energy stored in food.
Introduction: Elimination
- The body eliminates solid waste materials that cannot be absorbed into bloodstream.
- The large intestine concentrates feces.
- The wastes pass out of the body through the anus.
Orans of the Digestive System
The gastrointestinal tract begins with the oral cavity.
bucc/o
Cheek
Cheil/o, labi/o
Lips
Palat/o
Palate (roof of the oral cavity) (hard palate and soft palate)
Uvul/o
Uvula
Gloss/o, Lingu/o
Tongue
Tonsill/o
Tonsils
Gingiv/o
Gums
Dent/i, odont/o
Teeth
Side of tooth facing the tongue
Lingual side
Side of tooth facing the cheeks
Buccal side
Side of tooth facing the lips
Labial (facial)
Salivary glands
1.) Parotid gland
2.) Submandibular Gland
3.) Sublingual Gland
Lower esophageal sphincter (cardiac sphincter)
Ring like muscle that guards the entry of the stomach.
Pyloric sphincter
Guards the exit of the bolous before it enters the small intestine.
Villi
- In the lining of the small intestine. -Finger like projections that increase the surface area for digestive process to become far more efficient.
- The absorption is also far more efficient with villi that protrude into the lumen space of the small intestine.
Liver
-Produces bile.
-Helps maintain normal blood glucose levels.
-Manufactures blood proteins necessary for clotting.
-Releases bilirubin, a pigment in bile.
-Removes toxins and poisons from the blood.
Jaundice (Hyperbilirubinemia)
-Hemoglobin (is broken down by macrophages into)
- Heme and Globin
-Heme is broken down in bilirubin (excreted by liver in bile) and iron (reused or stored in liver, spleen, or bone marrow).
- Globin is broken down into protein.
The pancreas and it’s functions
Endocrine function:
-Insulin (lowers your sugar level)
-Glucagon (raises your sugar level in the blood)
(Goes to the bloodstream to cells)
Exocrine function:
-Enzymes are released to the duodenum to help start the digestive process
Food Pathway through the GI Tract
Food enters through the oral cavity and exits through the anus.
Oral Cavity (Salivary Glands release saliva to the oral cavity)
Pharynx
Esophagus
Stomach
(Liver releases bile to the gallbladder which release bile to the duodenum) Duodenum (Pancreas releases to the duodenum)
Jejunum
Ileum
Cecum
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Anus
Absorption
Passage of materials through the walls of the small intestine into the bloodstream.
Amino acids
Small building blocks of proteins; released when proteins are digested.
Amylase
Enzyme secreted by the pancreas and salivary glands to digest starch.
Anus
Terminal end or opening of the digestive tract to the outside of body.
Appendix
Blind pouch hanging from the cecum.
Bile
Digestive juice made in the liver and stored in the gallbladder; breaks up large fat globules; composed of bile pigments, cholesterol, and bile salts.
Bilirubin
Pigment released by the liver in bile.
Bowel
Intestine
Canine teeth
Pointed, dog-like teeth next to the incisors; also called cuspids or eyeteeth.
Cecum
First part of the large intestine.
Colon
Consist of the ascending, transverse, descending, and sigmoid segments.
Common bile duct
Carries bike from the liver and gallbladder to the duodenum; also called the choledochus.
Defacation
Elimination of feces from the digestive tract.
Deglutition
Swallowing
Dentin
Primary material found in teeth; covered by the enamel in the crown and a protective layer of cementum in the root.
Digestion
Breakdown of complex foods to simpler forms.
Duodenum
First part of the small intestine; measures 12 inches long.
Elimination
Act of removal of materials from the body.
Emulsification
Physical process of breaking up large fat globules into smaller globules.
Enamel
Hard, outermost layer of a tooth.
Enzyme
Chemical that speeds up reactions between substances; enzyme names end in -ase.
Esophagus
Tube connecting the throat to the stomach.
Fatty acids
Substances produced when fats are digested; a category of lipids.
Feces
Solid wastes; stool
Gallbladder
Small sac under the liver; stores bile.
Glucose
Simple sugar
Glycogen
Starch; glucose is stored in the form of glycogen in liver cells.
Hydrochloric acid
Substance produced by the stomach; necessary for digestion of food.
Ileum
Third part of the small intestine.