Physio Chapter 21a: Digestion
Which monosaccharide is most common as a carbohydrate?
Glucose
What is the purpose of chewing?
Grinding food and mixing with saliva
What chemical in the stomach is responsible for lowering the pH and sterilizing food?
HCl
What occurs when HCl moves into the esophagus from the stomach?
Heartburn
What word means that a material will not mix well with water?
Hydrophobic
The ileocecal valve would connect what two structures?
Ileum and secum (large and small intestine)
Most digestion of food molecules occurs in the
Jejunum
How much lipid digestion occurs in the stomach?
Less than 10%
What 3 enzymes break down fats?
Lipase, colipase, and phospholipase
What is bile used for?
Lipid digestion
What organ produces bile
Liver
What is the scientific term for chewing?
Mastication
Lipases break down triglycerides into
Monoglycerides and free fatty acids
What is the site of mastication and swallowing?
Oral cavity
What insulin-producing organ also produces digestive enzymes?
Pancreas
If you put pepsin in a beaker with some meat and leave it over night, very little digestion occurs. Why?
Pepsin needs to be activated by HCl
The movement of food through the intestines using wave-like contractions is called
Peristalsis
What stimulus begins the swallowing reflex?
Pressure against uvula
Where are feces compacted and stored until defecation?
Rectum
What are the two main functions of the colon?
Removal of water from feces, vitamin synthesis
What structures produce saliva?
Salivary glands
The mixing movements of the small intestine are called
Segmentation
What sense causes the greatest amount of salivation?
Smell
What are the two main functions of the stomach?
Storage and sterilization
Simple carbohydrates are all classified as
Sugars
Why can't fats be digested and absorbed without bile?
The clumps are too large
What is/are the function(s) of the rugae?
To allow expansion
One of the main functions of saliva is to moisten and lubricate food for swallowing
True
Whole proteins can be absorbed by the small intestine
True
How do the two esophageal sphincters work together to allow food into the stomach and prevent its movement back into the esophagus?
Upper esophageal sphincter opens and lower esophageal sphincter opens
Saliva contains several components. List all of them and their functions.
Water for liquefying, enzymes that begin digestion, mucus for lubrication, lysozyme, and immunoglobulins
Proteins are composed of chains of
amino acids
What stage of digestion occurs even when there is no food around you?
Cephalic
What is the scientific word for swallowing?
Deglutition
The first part of the small intestine that receives chyme and digestive juices is the
Duodenum
What two types of enzymes break down proteins?
Endopeptidases and exopeptidases
What structure covers the windpipe when swallowing?
Epiglottis
What part of the stomach connects the mouth with the stomach?
Esophagus
The epiglottis moves downward to cover the glottis when swallowing
False
Fats are composed of what two molecules?
Fatty acids and glycerol
What two components of our diet could be classified as complex carbohydrates?
Fiber and starch
What part of the stomach is the upper portion that is attached to the esophagus?
Fundus
What enzyme is found in saliva?
Amylase
What two chemicals act together to protect the stomach lining from the acid and digestive enzymes?
Bicarbonate buffer and mucus
What part of the stomach is the main portion, found in the middle?
Body
