Digestive System - Functions

Question 1

List the components of the digestive tract, in order.

Answer 1

Oral cavity, pharynx, oesophagus, stomach, small intestine, large intestine, rectum, anus

Question 2

Name the three portions of the pharynx.

Answer 2

Nasopharynx, oropharynx, laryngopharynx

Question 3

Name the functions of the digestive tract.

Answer 3

Ingestion, mastication, propulsion, mixing, secretion, absorption, elimination

Question 4

What is Mastication?

Answer 4

Process of mechanically breaking down food to increase total surface area to allow digestive enzymes to break down food.

Question 5

What is Propulsion and name the characteristics of this movement?

Answer 5

Movement of food through digestive tract, which takes approximately 24-36 hours.
Swallowing, peristalsis and mass-movement.

Question 6

Describe Swallowing [Propulsion].

Answer 6

Moves liquids or soft mass of foods/liquids, called a bolus, from oral cavity into oesophagus.

Question 7

Describe Peristalsis [Propulsion].

Answer 7

Move material through digestive tract.

Question 8

What are Peristaltic waves?

Answer 8

They are muscular contractions made up of a wave of relaxation of circular muscles in front of the bolus, followed by wave of strong contraction of circular muscles in front of bolus. This moves the bolus along the digestive tube.

Question 9

Describe Mass-movements [Propulsion]?

Answer 9

Contractions that move material in distal parts of large intestine to the anus.

Question 10

Describe Mixing.

Answer 10

Contractions that move food back and forth in digestive tract to mix it with digestive secretions to help break food into smaller pieces.

Question 11

What are Segmental contractions [Mixing]?

Answer 11

Mixing contractions that occur in the small intestine.

Question 12

Describe Secretion.

Answer 12

Help to lubricate, liquefy, buffer, and digest food.

Question 13

What are the types of secretions?

Answer 13

Mucus, water and enzymes

Question 14

What is the function of Mucus during digestion [Secretion]?

Answer 14

Lubricates lining of tract and protects epithelial cells from abrasion, stomach acid and digestive enzymes.

Question 15

What is the function of Water during digestion [Secretion]?

Answer 15

Liquefies food making it easier to digest and absorb.

Question 16

What is the function of Enzymes and where is it secreted [Secretion]?

Answer 16

Breaks down complex food molecules to smaller molecules.

Secreted from pancreas, small intestine, stomach and oral cavity.

Question 17

What is an Enzyme?

Answer 17

A protein catalyst that speeds up the rate of a chemical reaction.

Question 18

Describe Digestion.

Answer 18

The breakdown of large organic molecules into their component parts:
carbs -> mono
proteins -> amino
triglycerides -> fatty acids and glycerol

Question 19

What are the components of Digestion?

Answer 19

Mechanical digestion: involves mastication and mixing

Chemical digestion: achieved by digestive enzymes secreted along tract

Question 20

Describe Absorption.

Answer 20

Movement of molecules out of digestive tract and into circulatory or lymphatic system.
Achieved via Diffusion, Facilitated diffusion, Active transport, Osmosis, Symport, or Endocytosis.

Question 21

Describe Elimination.

Answer 21

Waste products removed from body via defecation. Occurs in large intestine, where material changed from liquefied to semi-solid by absorbing water and salts.