Digestive System

Question 1

In the digestive system, food undergoes two changes, what are they?

Answer 1

Mechanical and chemical transformations.

Question 2

What are the four stages of digestion?

Answer 2

1. Ingestion of food
2. Digestion of food
3. Absorption of Nutrients
4. Elimination of substances that have not been absorbed

Question 3

Can water, minerals, and vitamins be absorbed into the bloodstream without being digested?

Answer 3

Yes, since they aren’t complex molecules.

Question 4

Can carbohydrates, proteins, and fats be absorbed directly into the bloodstream?

Answer 4

No, because they’re molecules are so complex that they have to be digested into smaller molecules.

Question 5

Can carbohydrates, proteins, and fats be absorbed directly into the bloodstream?

Answer 5

No, because they’re molecules are so complex that they have to be digested into smaller molecules.

Question 6

When does digestion start?

Answer 6

When food is smelt or seen before it is eaten/ingested.

Question 7

What do Salivary glands do?

Answer 7

They produce saliva, which helps transform the complex molecules of carbohydrates into simpler ones.

Question 8

Is transforming the complex molecules of carbs into simpler ones a Mechanical or Chemical transformation?

Answer 8

Chemical transformation, because the nature is being changed.

Question 9

What does the tongue help with?

Answer 9

Moves food around while you masticate (chew) and breaks down food into smaller pieces with your teeth.

Question 10

Is breaking food into smaller pieces a Mechanical or Chemical transformation?

Answer 10

Mechanical, because the nature of the food isn’t being changed.

Question 11

What is another term for mushed-up food?

Answer 11

Bolus.

Question 12

What is the esophagus and what does it do?

Answer 12

An esophagus is like a stretchy pipe, roughly 10 inches long, this moves food from your throat into your stomach through muscle contractions know as peristalsis.

Question 13

When food is moved from the back of the throat into your stomach, what kind of transformation is this?

Answer 13

Mechanical transformation, because the nature isn’t being changed.

Question 14

What are the rhythmic muscle contractions of your esophagus called to help food move along?

Answer 14

Peristalsis.

Question 15

True or false: Is the stomach attached to the esophagus?

Answer 15

True.

Question 16

The stomach has three main jobs, what are they?

Answer 16

• Store food
• Break down the larger molecules into simpler ones
• Empty the liquid mixture into the small intestines

Question 17

The stomach is often compared to a mixer, mixing all the small balls of bolus into smaller pieces, is this a mechanical or chemical transformation?

Answer 17

Mechanical transformation, the nature doesn’t change.

Question 18

What are gastric juices, and what do they do?

Answer 18

Liquid secreted by the glands along the stomach’s walls, this helps break down proteins.

Question 19

When gastric juices break down protein, is this a mechanical or chemical transformation?

Answer 19

Chemical transformation, because the nature is being changed. The protein is being broken down into peptides and amino acids, which can easily enter the small intestines.

Question 20

What do the small intestine do?

Answer 20

When food enters the small intestine, the intestinal glands secrete intestinal juices that transform proteins into amino acids and fats into smaller molecules (chemical transformation). The small intestine also churns (mix) and moves food along through peristalsis.

Question 21

The small intestine is lined with villi, what do they do?

Answer 21

Allows some nutrients to be absorbed into the bloodstream, if needed (diffusion)

Question 22

What does the liver do?

Answer 22

Secretes bile in the gallbladder and emulsifies fats (separates water and fats)

Question 23

Is emulsifying fats a mechanical or chemical transformation?

Answer 23

Mechanical, the nature isn’t being changed.

Question 24

What does the pancreas do?

Answer 24

Secretes pancreatic juices that break down carbohydrates into smaller molecules of glucose.

Question 25

When pancreatic juices break down carbohydrates, what kind of transformation is this?

Answer 25

Chemical transformation, the nature is being changed.

Question 26

True or False: Are the liver & pancreas glands?

Answer 26

True.

Question 27

What does the large intestine do?

Answer 27

This is where most water, nutrients, and minerals are absorbed into the bloodstream.

Question 28

When all the nutrients needed are absorbed into the bloodstream what happens with the rest?

Answer 28

It transforms into a solid which is then expelled through the anus. (Physical transformation)