Digestive System Flashcards
consists of organs that ingest food, break it down, absorb the small molecules, and eliminate undigested wastes
digestive system
provides a steady supply of carbohydrates, proteins, fats, water, minerals, and vitamins to replace materials that leave the body
digestive system
it is the process by which the body obtains and uses certain components of food
nutrition
the chemicals taken into the body that are used to produce energy, to provide building blocks for new molecules, and to function in other chemical reactions
nutrients
refers to all chemical reactions on how the cells utilize the energy we have absorbed from food during digestion necessary to maintain life
metabolism
energy releasing process by which large molecules are broken down into smaller molecules
catabolism
energy requiring process by which small molecules are joined to form larger molecules
anabolism
it is the intake of solid or liquid food into the stomach
the normal route is through the oral cavity
ingestion
it is the process by which the teeth chew food in the mouth
mastication
it is the movement of food from one end of the digestive tract to the other
each segment of the digestive tract is specialized to assist in moving its contents from the oral end to the anal end
propulsion
moves liquids or a soft mass of food and liquid, called a bolus from the oral cavity into the esophagus
swallowing / deglutition
are muscular contraction consisting of a wave of relaxation of the circular muscles in front of the bolus, followed by a wave of strong contraction of the circular muscles behind the bolus, which force the bolus along the digestive tube
peristalsis
are contractions that move material in the distal parts of the large intestine to the anus
mass movements
some contraction do not propel food from one end of the digestive tract to the other but, rather, move it back and forth within the digestive tract to mix it with digestive secretions and help break it into smaller pieces
mixing
gentle contractions that churn the food with secretions in the stomach
mixing waves
mix food particles with digestive secretion in the small intestine
segmental contractions
as food moves through the digestive tract, secretions are added to lubricate, liquefy, buffer, and digest the food
secretion
secreted ___________ coats and protects the epithelial cells of the digestive tract from mechanical abrasion, stomach acid, and digestive enzymes
mucus
_____________ secreted by the oral cavity, stomach, small intestine, and pancreas break down large food molecules into smaller molecules that can be absorbed by the intestinal wall
enzymes
it is the breakdown of large organic molecules into their component parts
digestion
food is physically broken down into small particles which involves the mastication and chewing of food
mechanical digestion
break food molecules into small subunits accomplished by digestive enzymes secreted along the digestive tract
chemical digestion
it is the movement of molecules out of the digestive tract and into the circulation or into the lymphatic system
absorption
it is the process by which the waste products of digestion are removed from the body
during this process, which occurs primarily in the large intestine, water and salts are absorbed, changing the material in the digestive tract from liquefied to semi-solid
elimination