Chapter 14: Digestive System

Question 1

Why do we eat?

Answer 1

Because food provides the nutrients our body needs to carry out cellular activities.

Question 2

Why do humans need a digestive system?

Answer 2

So that we can break down food into small soluble molecules to absorb nutrients that can be used by our body cells.

Question 2

Describe the physical process of digestion.

Answer 2

Food is broken down into smaller pieces by physical means or mechanical means.

Question 3

What do those enzymes digest?

Answer 3

Carbohydrase: Carbohydrates
Proteases: Proteins
Lipases: Fats

Question 3

What are the products of the enzymes?

Answer 3

Carbohydrases: Simple sugars
Proteases: Amino acids
Lipases: Fatty acids and glycerol

Question 3

Describe the chemical process of digestion

Answer 3

Food is broken down into small molecules through the action of enzymes.

Question 3

What are the 3 main enzymes?

Answer 3

Carbohydrase, proteases, lipases

Question 4

Describe the types of digestion that takes place in the mouth.

Answer 4

Physical: Strong teeth and jaw muscles in the mouth cut and crush the food into smaller pieces.

Chemical: Saliva in the mouth contains carbohydrases. Partial digestion of starch begins in the mouth.

Other functions: Saliva softens and lubricates the food for easier swallowing.

Question 5

Describe the types of digestion that take place in the gullet.

Answer 5

Physical: None
Chemical: The gullet does not release any digestive juice. However, starch from the mouth continues to be digested by carbohydrases that were mixed with the food.
Other funcitons: Muscles of the gullet push the food towards the stomach.

Question 6

What types of digestion takes place in the stomach?

Answer 6

Physical: The stomach churns food into smaller pieces.
Chemical: The stomach releases gastric juice that contains proteases to digest proteins.
Other functions: The stomach releases gastric juice that contains hydrochloric acid, which kills harmful microorganisms and provides the right condition for proteases to act.
The stomach has a thick layer of mucus to protect its tissues from getting damaged by the hydrochloric acid and proteases in the gastric juice.
The muscles at both ends of the stomach control the food from enetering and leaving the stomach.

Question 7

What types of digestion takes place in the small intestine?

Answer 7

Physical: None
Chemical: The small intestine is the main site for chemical digestion due to the numerous enzymes released.
Fats are first digested here due to the presence of lipases in the digestive juices.
Carbohydrates, proteins and fats are fully digested here.

Question 7

Describe what happens in the rectum

Answer 7

Indigestable food and waste form faeces, which is temporarily stored here before it leaves the body.

Question 8

Describe what happens in the large intestine

Answer 8

Some of the remaining water and mineral salts in the food are absorbed here

Question 9

Describe what happens in the anus.

Answer 9

Faeces is released through this opening.

Question 10

What is diabetes?

Answer 10

It is a disease in which the level of sugar in the blood is too high.

Question 10

What are the end products of digestion?

Answer 10

They are small soluble molecules of digested food that are small enough to be absorbed into the blood.

Question 11

When does diabetes occur?

Answer 11

When the body produces insufficient insulin or when the body does not respond properly to insulin.

Question 12

What is insulin?

Answer 12

It is a hormone that keeps the blood sugar level balanced.

Question 13

What is diabetes often linked with?

Answer 13

Obesity, heart attacks, kidney problems, high blood pressure. blindness and stroke.

Question 14

How can we measure and monitor our blood sugar level?

Answer 14

Using a conventional blood sugar meter or a blood sugar monitoring device that is linked to a smartphone.

Question 15

What are some symptoms of diabetes?

Answer 15

Slow healing of wounds, constant hunger, frequent urination. tingling or numbness in hands and feet, unexplained weight loss, blurred vision

Question 16

How can we reduce the risk of diabetes?

Answer 16

1. Have regular health screenings
2. Have a healthy and balanced diet
3. Exercise regularly for at least 30 minutes and five days a week
4. Avoid smoking and drinking alcohol.

Question 17

What happens when one has constipation?

Answer 17

The faeces moves through the large intestine very slowly, resulting in too much water being absorbed from the faeces into the large intestine. The faeces then became hard and dry.

Question 18

How to prevent constipation?

Answer 18

Eating foods high in fibre, drinking more water, having adequate exercise.

Question 19

What are some possible causes of constipation?

Answer 19

Stress, consumption of certain medicines, not having enough fibre in the diet and not drinking enough water.

Question 20

What is gastritis

Answer 20

The painful swelling or inflammation of the stomach lining.

Question 21

What are symptoms of gastric pain?

Answer 21

Upper abdominal pain, nausea and bloating.

Question 22

What can gastritis be caused by?

Answer 22

Bacterial or viral infection, skipping meals, consuming alcohol or caffeine and too much oily food.

Question 23

What may eating contaminated food do to you?

Answer 23

Lead to diarrhoea or vomiting.

Question 24

What are some tips for food safety?

Answer 24

1. Use separate utensils and crockery for raw and cooked food.
2. Cover food properly before placing in fridge
3. Store cooked and ready-to-eat food above raw food in fridge
4. Keep raw food below 5 degrees
5. Check that bottled milk or drinks are tightly sealed.
6. Select food with an expiry date that has not passed
7. Do not consume food from cans that are badly dented or bloated.
8. Do not buy chilled or frozen food that is not stored at the appropriate temperature
9. Do not consume food that has turned mouldy.