Introduction

Question 1

Primary function

Answer 1

Primary function = physically and chemically modify
food so nutrients can be absorbed

Question 2

Five main processes

Answer 2

Ingestion = taking in food
Propulsion = moving food through digestive tract
Digestion = breaking food down (mechanical + chemic
Absorption = moving freed nutrients from gut into blood
Defecation = excreting undigested materials

Question 3

Neural control of homeostasis

Answer 3

Neural
Receptors and nerve plexus within digestive system respond to stimuli (mechanical/chemical/osmotic) and/or interact with CNS
• Influence secretion of digestive juices and/or contraction of gastrointestinal tract
•E.g. sight/smell of food causes medulla oblongata (CNS) to stimulate the stomach to ‘prepare’ for incoming food

Question 4

Hormonal control of homeostasis

Answer 4

• Hormonal
- Specialised epithelial cells (endocrinocytes) in digestive system release hormones
• Influence release of digestive juices and feelings of hunger/satiety

Question 5

Alimentary Canal

Answer 5

Continuous, coiled, hollow tube which runs from mouth to anus

Question 6

What structures are included the alimentary canal

Answer 6

Mouth, pharynx, oesophagus, stomach, small intestine and large intestine

Question 7

Accessory digestive organs

Answer 7

Accessory digestive organs
Includes teeth, tongue, salivary glands, pancreas, liver and gallbladder

Question 8

Layers of the alimentary canal (deep to superficial)

Answer 8

• Mucosa -> submucosa -> muscularis -> serosa

Question 9

Mucosa

Answer 9

• Surface epithelium = stratified squamous or simple columnar
• Lamina propria = connective tissue, blood, vessels lymphatic vessels,
  mucosa-associated lymphoid tissue (MALT)
  Muscularis mucosa = thin layer of smooth muscle

Question 10

Submucosa

Answer 10

Submucosa
- Connective tissue, blood vessels, nerve plexus, lymphatic vessels, submucosal glands

Question 11

Muscularis externa

Answer 11

• Double layer of smooth muscle and/or skeletal muscle (inner = circular;
  outer = longitudinal)

Question 12

Serosa

Answer 12

Visceral peritoneum and loose connective tissue (or adventitia)