What is the sequential order, mouth to anus, of the digestive organs making up the alimentary canal
mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
The stomach epithelium secretes several substances, including alkaline mucus ad intrinsic factor. What is the function of each of these secretions
Alkaline mucus protects the stomach wall from being digested. Intrinsic factor is needed for intestinal absorption of vitamin B12
Which muscular sphincter regulates the flow of chyme in to the small intestine
The pyloric sphincter
What are villi, and why are they important
Villi are extensions of the mucosa of the small intestine They increase the surface area of the small intestine tremendously for nutrient absorption.
What are the two main functions of the lrg intestine?
Water absorption and absorption of some vitamins made by resident bacteria.
What is the digestive role of bile? What organ secretes bile?
Bile, secretes by the liver, acts as detergent to mechanically break up large fat masses into smaller ones for enzymatic digestion.
Only one organ produces enzymes capable of digesting al groups f food. Which organ is this?
What is the order of food processing
Ingestion, mechanical digestion, propulsion, chemical digestion, absorption, defecation
How do mechanical and chemical digestion differ from each other?
Mechanical digestion breaks down food physically by chewing, churning, and segmentation of the small intestine. Chemical digestion uses enzymes to break the chemical bonds of the food molecules and releases it.
What happens during the buccal stage of swallowing?
This the voluntary stage in which the chewed food is pushed into the pharynx by the the tongue.
How does segmentation differ from peristalsis in terms of moving substances along the GI tract
The main goal of segmentation is to mix the food thoroughly, though some propulsion occurs. Peristalsis is a propulsive activity.
What does it mean when we say that food "went down the wrong tube" ?
Food went down the air passageway (trachea)instead of the digestive passage (esophagus)
Why is it necessary for the stomach contents to be so acidic?
Pepsin, the main enzyme of the stomach, needs acidic conditions to work.
Name the layers of the alimentary tube wall from the lumen outward
mucosa (innermost), submucosa, muscularis externa, serosa
The GI tube tissue layer responsible for the actions of segmentation and peristalsis is the?
Release of secretory leads to
increased secretory activity of liver cells, release of bicarbonate-rich fluid by the pancreas.
What is pulp?
area of a tooth that contains connective tissues, blood vessels, and nerve fibers. It supplies nutrients to the tooth tissues and proves for tooth sensations.
Name two regions of the digestive tact where mechanical food breakdown occurs, and explain how it is accomplished in those regions.
mixing of food in the mouth by the tongue, churning, segmentation (small intestine)
How do segmental and peristaltic movements differ?
Peristalsis is involuntary and involves alternating waves of contraction and relaxation of the muscles in the organ wall. Segmentation moves food only back and forth across the internal wall of the organ, serving to mix it with the digestive juices. Thus, segmentation is more an examples of mechanical digestion than of propulsion.