Introduction to the Digestive System Flashcards
What is the digestive system?
organs that break down food, absorb its nutrients, and expel any remaining waste
What are the three main functions of the digestive system? Define each function.
digestion of food, absorption of nutrients from food, and elimination of solid food waste.
Describe the GI tract.
a long, continuous tube that connects the mouth with the anus
Distinguish between the upper and lower GI tracts.
Upper GI tract is where food enters, the mouth and stomach
Lower GI tract is where food waste leaves, the small and large intestines
Relate the tissues in the walls of GI tract organs to the functions the organs perform.
Mucosa: Secretes and absorbs substances
Submucosa: Absorbs and carries nutrients after digestion and controls muscles of the GI tract organs
Muscularis externa (Muscle layer): Contracts and relaxes in waves to move food through the GI tract
Serosa: separates the organs from surrounding cavities and tissues.
Identify accessory organs of digestion and their general function in digestion.
Liver: Secretes bile to make lipids smaller and more digestible, and reduce acidity in food
Gallbladder: Removes water from bile to make it stronger, then secretes into small intestine as needed for digestion
Pancreas: Secretes and releases digestive enzymes into small intestine for chemical digestion, and secretes bicarbonate to lessen the small intestine’s acidity
Identify the points in the GI tract where food becomes a bolus, chyme, and feces, respectively.
Bolus: When food is swallowed and moves from mouth to pharynx
Chyme: When food passes from stomach to small intestine
Feces: When food moves from large intestine out through the anus
Does food pass through the pancreas? Why or why not?
No
It’s not part of the GI tract where food passes through.
True or False. Absorption mainly occurs in the stomach.
False
True or False. Some chemical digestion occurs in the mouth.
True
Most chemical digestion occurs in the _____________ .
A. Gall bladder
B. Stomach
C. Small intestine
D. Large intestine
C. Small intestine
Describe one way in which proteins are at least partially chemically digested in the digestive system.
The enzyme pepsin in the stomach helps to chemically digest proteins.
Describe one way in which carbohydrates are at least partially chemically digested in the digestive system.
The enzyme amylase in the saliva starts to chemically digest carbohydrates.
If the villi in your small intestine were damaged and could not function normally, what effect might this have on your body? Explain your reasoning.
Because the villi are important for absorption, it could interfere with absorption of nutrients from food
The esophagus is considered:
A. An accessory organ of the digestive system
B. Part of the upper GI tract
C. Part of the lower GI tract
D. The longitudinal muscle
B. Part of the upper GI tract
