Lesson 4: Digestive And Excretory Systems

Question 0

Define esophagus.

Answer 0

A long, straight tube that connects the pharynx to the stomach.

Question 1

Define the digestive system.

Answer 1

The organs that break down food so it can be used by the body.

Question 2

Define stomach.

Answer 2

The saclike, digestive organ that is between the esophagus and the small intestine and that breaks down food by the action of muscles, enzymes, and acids.

Question 3

Define small intestine.

Answer 3

The organ between the stomach and the large intestine where most of the breakdown of food happens and most nutrients are absorbed.

Question 4

Define large intestine.

Answer 4

The broader and shorter portion of the intestine, where water is removed from the mostly digested food to turn the waste into semisolid feces, or stool.

Question 5

Define pancreas.

Answer 5

The organ that lies behind the stomach and that makes digestive enzymes and hormones that regulate sugar levels.

Question 6

Define liver.

Answer 6

The largest organ in the body; it makes bile, stores and filters blood, and stores excess water as glycogen.

Question 7

Define excretory system.

Answer 7

The system that collects and excretes nitrogenous wastes and excess water in the form of urine.

Question 8

Define kidney.

Answer 8

One of the organs that filters wastes from the blood, excrete products as urine, and regulate the concentration of certain substances in the blood.

Question 9

Define nephrons.

Answer 9

The unit in the kidneys that filters blood.

Question 10

Define urine.

Answer 10

The liquid excreted by the kidneys, stored in the bladder, and passed through the urethra to the outside of the body.

Question 11

Define enzyme.

Answer 11

A type of protein that speeds up metabolic reactions in plants or animals without being permanently changed or destroyed.

Question 12

What is the digestive system?

Answer 12

The digestive system breaks down food you eat into nutrients to provide energy for cells.

Question 13

What are the two types of digestion?

Answer 13

Chemical and mechanical digestion.

Question 14

What is chemical digestion?

Answer 14

The process in which large molecules of food are broken down into smaller molecules so that they can pass in the bloodstream.

Question 15

What is mechanical digestion?

Answer 15

The breaking, crushing, and mashing of food.

Question 16

What are the parts of the digestive system?

Answer 16

The mouth, the esophagus, the stomach, the small intestine, and the large intestine.

Question 17

Explain what the mouth does to help digestion.

Answer 17

Mechanical and chemical digestion begins in the mouth. The food is moistened by saliva and moves down the esophagus.

Question 18

Explain what the esophagus does to help digestion.

Answer 18

Waves of muscle contractions called peristalsis move the food from the esophagus to the stomach.

Question 19

Explain what the stomach does to help digestion.

Answer 19

The stomach is a muscular bag that crushes food and contains acids and enzymes for killing bacteria and breaking down proteins.

Question 20

Explain what the small intestine does to help digestion.

Answer 20

The food travels to the small intestine after it has been reduced to a soupy mixture called chyme. The small intestine is where most chemical digestion takes place and most nutrients are absorbed.

Question 21

Explain what the large intestine does to help digestion.

Answer 21

The food’s nutrients are absorbed and the remaining waste is removed from the body in the form of feces.

Question 22

Where are nutrients absorbed?

Answer 22

In the small and large intestines.

Question 23

Explain how nutrients are absorbed in the small intestine.

Answer 23

The small intestine contains folds, villi, and microvilli which help it absorb nutrients. The folds create more surface area for nutrients to be absorbed. Each fold is covered with villi and microvilli. Villi absorb nutrients and microvilli increase surface area of the villi.

Question 24

Explain how nutrients are absorbed in the large intestine.

Answer 24

The large intestine produces feces. The bacteria that live inside the large intestine feed off the undigested food. The rectum is where feces is stored, and the anus is where the feces comes out.

Question 25

What are the functions of the excretory system?

Answer 25

To sweat, to exhale, and to produce urine and feces.

Question 26

Explain how you sweat.

Answer 26

Waste products such as excess salts are released through the skin when you sweat.

Question 27

Explain how you exhale.

Answer 27

Lungs release water and toxic carbon dioxide when you exhale.

Question 28

Explain how you produce urine and feces.

Answer 28

Kidneys remove cellular waste from the body and the digestive system eliminates feces.

Question 29

What organs are in the urinary system?

Answer 29

Kidneys, ureters, bladder, urethra.

Question 30

Explain how the kidneys work in the urinary system.

Answer 30

The kidney is one of the pair of organs that remove waste from the blood.

Question 31

Explain how the ureters work in the urinary system.

Answer 31

The ureters is where urine travels after it has been in the kidneys.

Question 32

Explain how the bladder works in the urinary system.

Answer 32

The bladder is a saclike organ that stores urine.

Question 33

Explain how the urethra works in the urinary system.

Answer 33

Urine exits the bladder through the urethra.

Question 34

How does the urinary system maintain homeostasis?

Answer 34

Your cells have to maintain a certain level of salt and water to function properly. Chemical messenger called hormones signal the kidneys to filter more or less salt and water, depending on the level of salt and water in the body.