Nutritional Foundations ch 3
An example of a problem caused by a sphincter muscle not operating properly is
Heart burn
Chemicals that act as messengers are called
Hormones
If a meal is eaten at noon, by 8 PM that evening, the food would probably be in the
Small intestine
Peristalsis is necessary to make it possible for people to _____ food.
Swallow
If peristalsis were to reverse direction, the result would be
Vomiting
Dehydration may occur after
Vomiting and diarrhea
People tend to feel full for longer after eating a high-fat meal rather than a low-fat meal because
fat in the duodenum causes release of gastric inhibitory polypeptide, which decreases peristalsis of the stomach.
Release of digestive secretions into the small intestine is caused by _____ that are released when _____.
hormones; enters the small intestine
The most important function of the villi of the small intestine is to
increase the surface area for absorption of nutrients.
The body process over which people have most conscious control is
ingestion
A person who complains of problems with gas, bloating, and diarrhea if he or she eats breakfast cereal with milk, but not if he or she eats pancakes or waffles, may have
lactose intolerance.
If the large intestine did not carry out its main function, feces would be
liquid.
The best description of an enzyme is a(n)
organic catalyst.
Nutrients are considered to have become part of the body only once they have
passed through the microvilli cells
An example of catabolism is the
the breakdown of glucose to provide energy
If the small intestine did not release secretin, the result would be that
the chyme entering the small intestine would be too acidic for digestive enzymes to work.
If pancreatic secretions were absent,
there would be no bicarbonate to buffer the acid in chyme entering the duodenum.
The adjectives mechanical and chemical describe two
types of action that result in digestion.
Examples of mechanical digestion include
churning and mixing of food in the stomach.
A busy and stressed person who eats very few fruits and vegetables and does not take time to exercise is likely to experience
constipation
The action of salivary amylase in the mouth is an example of
chemical digestion.
If the speed of peristalsis were to increase, the result would be
Diarrhea
Healing of a broken bone is an example of
anabolism
The most important functions of the small intestine are
digestion and absorption
What is the main difference between passive diffusion and active transport?
Active transport requires energy; passive diffusion does not.
The part of the digestive system that is easiest to live without is the
Appendix
The bloodstream carries nutrients to the liver soon after absorption because the liver
is an important site of metabolism and production of vital substances.
Most mechanical breakdown of food occurs in the
mouth and stomach.
The layer of the gastrointestinal tract that contributes most to mechanical digestion of food is the
muscularis
When someone walks by a bakery and smells the fresh bread, his or her mouth starts to water. As the person thinks about eating the fresh bread, another digestive function that starts to occur is
release of the hormone gastrin in the stomach.