Digestive System

Question 1

Why do we need a digestive system?

Answer 1

Our bodies can’t use the nutrients we eat as they are but must transform them to allow them to do their job.

Question 2

The role of the digestive system

Answer 2

Break down the food into molecules so that they are small enough to be absorbed by the body and to eliminate the undigested food from the body

Question 3

What two parts make up the digestive system?

Answer 3

The digestive tract and the digestive glands

Question 4

Digestive tract

Answer 4

The physical route that the food takes from the beginning to the end of its journey through the human body

Question 5

Digestive glands

Answer 5

Produce chemical secretions that are needed to digest food as it travels along the digestive tract

Question 6

Components of the digestive tract

Answer 6

Mouth 
Pharynx 
Esophagus 
Stomach 
Small intestine 
Large intestine

Question 7

Components of the digestive glands

Answer 7

Sal vary glands 
Gastric glands 
Liver 
Pancreas 
Intestinal glands

Question 8

What are the functions of the digestive system

Answer 8

Ingestion of food
Digestion of food
Absorption of food
Elimination of fecal matter

Question 9

What is ingestion?

Answer 9

The action of introducing food or liquid into the digestive system

Question 10

What 2 mechanism allow the progression of the food in the digestive system?

Answer 10

Deglutition and peristalsis

Question 11

What is deglutition?

Answer 11

Swallowing the food

Question 12

Peristalsis

Answer 12

Series of involuntary wave like muscle contacterions which move along the digestive tract

Question 13

What happens when we swallow?

Answer 13

The epiglottis closes the trachea and the uvula moves backwards to close off the nasal cavity. Food can then travel to the esophagus without getting into the respiratory tract.

Question 14

What is digestion?

Answer 14

The transformation of complex molecules into simpler molecules called nutrients that can be used by the body

Question 15

What are the two types of transformations?

Answer 15

Mechanical and chemical

Question 16

Mechanical transformation

Answer 16

Consists of physically breaking down food into smaller substances in preparation for subsequent chemical transformation

Involves chewing and churning

Question 17

Chewing

Answer 17

Process of crushing and grinding food

Question 18

Churning

Answer 18

Produced by muscle contractions, which mix food from secretions from the digestive glands. Takes place primarily in the stomach and small intestine

Question 19

Chemical transformation

Answer 19

Break down complex molecules of food into simpler molecules. The facilitate absorption and subsequent use by the body

Question 20

Protein molecule

Answer 20

Amino acids

Question 21

Starch molecules

Answer 21

Glucose

Question 22

Fat molecule

Answer 22

Fatty acids

Question 23

Digestion ends at….

Answer 23

It ends at the small intestine when nutrients have been broken down to their molecular components and now pass through the lining of digestive tract and can be used by the body

Question 24

What is absorption?

Answer 24

The passage of nutrients from the digestive tract to the blood or lymph

Question 25

Where does most food absorption take place?

Answer 25

Small intestine

Question 26

What are villi

Answer 26

Folds in the small intestine. They increase the surface are through which nutrients can be absorbed. They have blood and lymphatic vessels that the nutrients use to get into the rest of the body

Question 27

What nutrients are absorbed in the small intestine?

Answer 27

``` Glucose Amino acid Fatty avid Glycerol and water (minute amounts) Vitamins (minute amounts) Minerals (minute amounts) ```

Question 28

Elimination

Answer 28

Digestive residue then enters the large intestine contains very little nutrients Arrives in the large intestine in liquid form Water is slowly absorbed Residue that reaches the rectum is usually solid has a little water left From the rectum the feces is expelled through the anus

Question 29

The oral cavity

Answer 29

Where mechanical and chemical digestion foods begin. Breaks down starch with saliva

Question 30

Stomach

Answer 30

Primary role of the stomach is food storage. Allows to store large amounts of food because it stretches

Question 31

Small intestine

Answer 31

Most of the digestion and absorption takes place there.

Question 32

Large intestine

Answer 32

Divided into several section (cecum, colon, appendix, and rectum terminating in the anus)

Question 33

Salivary glands

Answer 33

Secrete between 1 and 1.5L of saliva a day. Proteins and enzymes are found in saliva.

Question 34

Saliva

Answer 34

Acts as a lubricant for mouth and food bolus. It limits the scratches in the oral cavity. It also contains antibacterial agents which limit the introduction of bacteria into the digestive tract

Question 35

Gastric glands

Answer 35

Scattered throughout the internal surface of the stomach

Question 36

Intestinal glands

Answer 36

Located at the bottom of the villi. There are about 50 million of these glands and they can secrete up to 2 L of intestinal juice in the small intestine

Question 37

Liver

Answer 37

Role is mainly secretion of bile. Stored in the gallbladder

Question 38

Pancreas

Answer 38

Secretes between 1.2 L in 1.5 L of pancreatic juice. Is mainly responsible for the secretion of two hormones: insulin and glucagon. These hormones are responsible for regulating the level of glucose in the blood