9.1 Digestion

Question 1

What is the function of the organs located within the gastrointestinal (GI) tract?

Answer 1

To hydrolyze, or break down, the macromolecules found in food.

Question 2

What are the subunit molecules that can cross plasma membranes?

Answer 2

• Monosaccharides
• Amino acids
• Fatty acids
• Glycerol

Question 3

How do subunit molecules cross plasma membranes?

Answer 3

Using facilitated and active transport.

Question 4

What happens to the nutrients made available after digestion?

Answer 4

They are transported by the blood to our cells.

Question 5

True or False: The primary function of the GI tract is to absorb nutrients.

Answer 5

False

Question 6

Fill in the blank: The process of breaking down macromolecules in food is called _______.

Answer 6

hydrolysis

Question 7

What is ingestion?

Answer 7

Intake of food via the mouth.

Question 8

Define digestion.

Answer 8

Mechanically or chemically breaking down foods into their subunits.

Question 9

What is mechanical digestion?

Answer 9

Chewing in the mouth and contractions of smooth muscles in the stomach.

Question 10

What is chemical digestion?

Answer 10

Digestive enzymes hydrolyze macromolecules into subunits.

Question 11

Where does digestion begin?

Answer 11

In the mouth.

Question 12

Where is digestion completed?

Answer 12

In the small intestine.

Question 13

Fill in the blank: Digestion begins in the _______.

Answer 13

mouth

Question 14

Fill in the blank: Mechanical digestion occurs through _______ and contractions of smooth muscles.

Answer 14

chewing

Question 15

True or False: Chemical digestion occurs only in the stomach.

Answer 15

False

Question 16

List the five processes of digestion.

Answer 16

• Ingestion
• Digestion
• Absorption
• Assimilation
• Egestion

Question 17

What is the process of food being passed from one organ to the next called?

Answer 17

Peristalsis

Peristalsis involves contractions of smooth muscle.

Question 18

What is the movement of nutrients across the GI tract wall into the blood called?

Answer 18

Absorption

Absorbed nutrients are then delivered to cells.

Question 19

What is the process of removing indigestible wastes from the body?

Answer 19

Elimination

This process includes defecation.

Question 20

Fill in the blank: The movement of food through the digestive system involves _______.

Answer 20

peristalsis

Question 21

True or False: Absorption is the process of removing indigestible wastes.

Answer 21

False

Absorption refers to the uptake of nutrients, not waste removal.

Question 22

What are the three main processes involved in digestion?

Answer 22

• Movement
• Absorption
• Elimination

Question 23

What is the lumen?

Answer 23

The open area of a hollow organ or vessel; in the Gl tract, it contains food or feces.

Question 24

What are the four layers of the digestive tract?

Answer 24

• Mucosa
• Submucosa
• Muscularis
• Serosa

Question 25

What is the function of the mucosa?

Answer 25

Produces mucus for protection and also produces digestive enzymes.

Question 26

What type of tissue is the submucosa made of?

Answer 26

Loose connective tissue.

Question 27

What does the submucosa contain?

Answer 27

* Blood vessels * Lymphatic vessels * Nerves

Question 28

What are the two layers of the muscularis?

Answer 28

* Inner circular layer * Outer longitudinal layer

Question 29

What is the primary function of the muscularis layer?

Answer 29

Moves food along the Gl tract.

Question 30

What is the serosa?

Answer 30

The outer lining that is part of the peritoneum.

Question 31

Fill in the blank: The _______ is the innermost layer of the digestive tract.

Answer 31

Mucosa

Question 32

True or False: The muscularis layer consists of three layers of muscle.

Answer 32

False

Question 33

What is diverticulosis?

Answer 33

A condition in which the mucosa of any part of the GI tract (usually the large intestine) pushes through the other layers and forms pouches where food collects. ## Footnote Diverticulosis is characterized by the formation of diverticula, which are small bulging pouches that can develop in the lining of the digestive system.

Question 34

What is diverticulitis?

Answer 34

When the pouches formed by diverticulosis become infected. ## Footnote Diverticulitis occurs in 10-25% of people with diverticulosis and can lead to severe complications if not treated.

Question 35

What percentage of people with diverticulosis develop diverticulitis?

Answer 35

10-25% ## Footnote This statistic highlights the potential risk for individuals diagnosed with diverticulosis.

Question 36

Fill in the blank: Diverticulosis usually affects the _______.

Answer 36

large intestine ## Footnote The large intestine is the most common site for diverticulosis to occur within the GI tract.

Question 37

What is Inflammatory bowel disease (IBD)?

Answer 37

Chronic diarrhea, abdominal pain, fever, and weight loss. ## Footnote IBD is a term used to describe disorders involving chronic inflammation of the digestive tract.

Question 38

What symptoms are associated with Irritable bowel syndrome (IBS)?

Answer 38

Abdominal pain, constipation, and diarrhea due to contractions of the muscularis. ## Footnote IBS is a functional gastrointestinal disorder characterized by these symptoms, and the underlying cause is not known.

Question 39

What is the underlying cause of IBS?

Answer 39

Not known. ## Footnote The exact mechanisms leading to IBS remain unclear, making it a complex condition to study.

Question 40

Fill in the blank: IBD is characterized by _______ diarrhea.

Answer 40

[chronic] ## Footnote Chronic diarrhea is one of the main symptoms that define Inflammatory bowel disease.

Question 41

True or False: The underlying cause of IBD is well understood.

Answer 41

False. ## Footnote While some factors contributing to IBD have been identified, the exact cause remains elusive.