Human Digestion

Question 1

What is the alimentary Canal?

Answer 1

The continuous tube extending from the mouth to the anus; also called gastrointestinal (GI tract or the “food tube”.

Question 2

List the seven components of the alimentary canal, starting with the mouth, and following the path of food through the body.

Answer 2

Mouth (oral cavity) 
Pharynx
esophagus
stomach
small intestine
large intestine
rectum

Question 3

Contrast mechanical and chemical digestion in the mouth.

Answer 3

Mechanical: teeth break down food into smaller pieces.
Chemical: enzymes break down chemical bonds in the starch.

Question 4

What is salivary amylase?

Answer 4

An enzyme contained in saliva that digest starch into maltose, a disaccharide.

Question 5

What is peristalsis?

Answer 5

Wavelike contractions and relaxations of circular muscles in the oesophagi that push food into the stomach.

Question 6

What is the stomach?

Answer 6

Mechanical and chemical digestion takes place here. Food enters from the oesophagus and is broken down by muscular contraction, enzymes and hydrochloric acid.

Question 7

What are gastric juices?

Answer 7

Digestive liquid present in the stomach; composed of water, hydrochloric acid and enzymes.

Question 8

What is pepsin?

Answer 8

Gastric (stomach) enzyme that digests protein into smaller polypeptides.

Question 9

What is Chyme?

Answer 9

The partially digested contents of the stomach, in the form of a paste, that pass to the small intestine via the duodenum.

Question 10

What is the pyloric sphincter

Answer 10

A muscular valve between the stomach and small intestine.

Question 11

List four enzymes present in intestinal juice and their functions.

Answer 11

• maltase digests maltose (from starch)
  lactase digest milk sugar (lactose)
  sucrase digests cane sugar (sucrose)
  lipase digests fat.

Question 12

List four enzymes present in pancreatic juice and their functions.

Answer 12

Chymotrypsin digests protein.
trypsin digests protein.
amylase digests starch
pancreatic lipase digests fat.

Question 13

What is the pancreas?

Answer 13

An organ located behind the stomach that secretes enzymes used in digestion as well as the hormones insulin and glucagon near the duodenum.

Question 14

What is the Liver?

Answer 14

An organ next to the stomach that acts as the body’s filter among several function it produces substances which break down fat, and other that affect sugar metabolism.

Question 15

What is bile?

Answer 15

Breaks down large fat droplets into smaller droplets on which enzymes can act more efficiently. It is produced by the liver, stood in the gall bladder and relaxed through a duct into the small intestine.

Question 16

What are the end products in the digestion of proteins, fats and carbohydrates?

Answer 16

Proteins: amino acids
Fats: fatty acides and glycerol
Carbohydrates: simple sugars (monosaccharides)

Question 17

What are the functions of mucus in the stomach?

Answer 17

Protects stomach walls from the gastric juices.
lubricates stomach wall, which facilitates movement of food.
protects cells from abrasion by food.

Question 18

What is the function of bicarbonate secreted by the pancreas?

Answer 18

Bicarbonate release into the small intestine neutralises the stomach acid and permits the pancreatic enzymes to function.

Question 19

What is the small intestine?

Answer 19

Located between the stomach and the large intestine, where the majority of digestion and absorption takes place.

Question 20

What is the Duodenum?

Answer 20

The first part of the small intestine; located right after the stomach. Near the pancreas.

Question 21

What are the intestinal villi?

Answer 21

Numerous finger-like projections that line the small intestine and increase the surface are for absorbing nutrients.

Question 22

What are Lacteal?

Answer 22

A lymph vessel inside each intestinal villus; faty acids and glycerol are absorbed into them and are carried into the lymph system.

Question 23

What is the large intestine? (Colon)

Answer 23

Compacts and removes water and salts from the undigested material (fiber) passing through; no digestion takes place here.