Digestion - Lesson 1

Question 1

What are the 4 phases of the digestive process?

Answer 1

1 - Ingestion

2 - Digestion

3 - Absorption

4 - Elimination

Question 2

What is ingestion in simple terms?

Answer 2

swallowing & peristalsis

Question 3

What is Digestion in simple terms?

Answer 3

Physical - Teeth and muscular stomach

Chemical - Enzymes break down food into nutrients

Question 4

What is absorption in simple terms?

Answer 4

Diffusion and active transport of nutrients into the blood

Question 5

What is Elimination in simple terms?

Answer 5

Defecation - Removal of undigested material

Question 6

What are the structures in the digestive system?

Answer 6

Mouth

Pharynx

Esophagus

Stomach

Small Intestine

Large Intestine

Rectum

Question 7

Digestion begins with ingestion - What is involved with ingestion?

Answer 7

Food is brought into the mouth

The chewing action of the teeth starts to break down the food.

Salivary Glands secrete saliva (mucus & salivary amylase)

salivary amylase is a hydrolytic enzyme that begins breaking down carbohydrates

The tongue pushed food against the hard palate breaking it down more

The tongue then pushes the food towards the phalynx which starts the swallowing reflex

Question 8

What is salivary amylase?

Answer 8

a hydrolytic enzyme that begins breaking down carbohydrates

Question 9

What is the hard palate?

Answer 9

The roof of the mouth

Question 10

What is a bolus?

Answer 10

A clump of chewed food

Question 11

Describe the swallowing reflex

Answer 11

As the bolus is swallowed, the soft palate prevents food from entering your nasal cavity by pushing it upward

The uvula also ‘kicks’ food away from the nasal cavity

the epiglottis closes the entry to the trachea so food doesn’t enter the lungs

Question 12

What is the esophagus?

Answer 12

A muscular tube about 20cm long

secretes mucus to reduce friction

Moves food from the throat to the stomach using muscle movement called peristalsis (wave-like contraction of muscle)

Smooth muscle (you can’t control it)

Question 13

Where is the cardiac sphincter? What does it do?

Answer 13

It is on the esophagus at the entrance to the stomach.

It is a ring of muscle that prevents food from going back up the esophagus

If acid from the stomach gets back into the esophagus, you get “heartburn”

Question 14

What does GI stand for?

Answer 14

Gastrointestinal Tract