final 5

Describe the different types of motility and mixing within the digestive system

-Motility Muscular contractions that mix and move forward the contents of the digestive tract Two types of digestive motility Propulsive movements Push contents forward through the digestive tract -Mixing movements mix food with digestive juices promotes digestion of foods Facilitates absorption by exposing all parts of intestinal contents to absorbing surfaces of digestive tract

What can be found in (normal) feces?

-Water, electrolytes, mucus, bacteria, and bile pigments.

What is bile? How does it work?

-a bitter greenish-brown alkaline fluid that aids digestion and is secreted by the liver and stored in the gallbladder. Bile is a yellowish-green liquid that hepatic cells continuously secrete. It contains water, bile salts, bile pigments, cholesterol, and electrolytes. The bile salts in it work to emulsify fats as well as help absorb fatty acids, cholesterol, and fat-soluble vitamins.

What are the functions of the accessory organs/glands in the digestive system?

-salivary glands -liver -gallbladder -pancreas

What is heartburn?

A back-flow of stomach acid into the esophagus that causes a burning sensation.

Describe the digestion and absorption of carbohydrates, proteins, and fats

Carbs begin to digest in the mouth, where enzymes in saliva start breaking complex molecules down into simpler sugars. Chewed-up carbs then pass through the esophagus and stomach with little additional digestion. In the small intestine, they are broken down into the simplest sugar molecules, which are then absorbed through the small intestine walls into the bloodstream and used by the body as fuel or sent for storage in the liver for use at a later time. Fiber, the indigestible cell walls found in carb plant foods such as beans, brown rice and whole wheat, passes through the digestive tract essentially undigested. Protein is found in meat, eggs, dairy products and beans, and is used by the body to build muscle and organs. Protein molecules are quite large. Chewing helps break proteins down into smaller particles for digestion. Chemical protein digestion starts in the stomach, where enzymes start to soften the protein molecules. A number of enzymes, including substances from the pancreas, then break down protein into its component amino acids in the small intestine. Amino acids are absorbed through the wall of the small intestine into the bloodstream and distributed throughout the body to repair injuries and replace dying cells. Fats and oils do not easily dissolve into the watery digestive juices of the intestinal tract. Bile, produced by the liver and stored in the gallbladder, can attach to molecules of both water and fat. Bile breaks up conglomerations of fat in the digestive tract into smaller emulsified particles, where lipase, a fat-digesting enzyme, can break it down. The broken down fat particles -- fatty acids and cholesterol -- are absorbed through the intestinal walls into the bloodstream, where they accumulate in the chest veins and are then carried to fat-deposit areas throughout the body to be stored and used for fuel when necessary

What are the functions of the digestive system

Ingest food, breakdown food into small molecules, absorb these nutrient molecules, and elimate nondigestible wastes

Describe the nervous system's role for digestion

Parasympathetic impulses increase activities of digestive system. Sympathetic impulses inhibit certain digestive actions. -under control of the Autonomic Nervous System (ANS) -controlled by hormones released by glands in the body

Differentiate between the functions of the different organs of the GI tract.

The digestive system is made up of the gastrointestinal (GI) tract—also called the digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus.

Differentiate between primary and permanent teeth

There are 20 primary (baby) teeth. There are 32 secondary (permanent) teeth.

Describe the different enzymes/chemicals used within digestion, where they are used, and what they digest

proteases and peptidases split proteins into small peptides and amino acids., lipases split fat into three fatty acids and a glycerol molecule., amylases split carbohydrates such as starch and sugars into simple sugars such as glucose., nucleases split nucleic acids into nucleotides