Digestion

Question 1

Identify all digestive system organs & their functions?

Answer 1

Mouth - saliva breaks carbs (mastication)
Oesophagus - moves bolus of food into stomach
Stomach - churns with digestive juices to break down food. Mechanical and Chemical digestion
Small intestine - digestion and absorption.
Large intestine - removes water and stores solid waste
Rectum: The rectum stores stool until the body is ready to evacuate it.
Anus: The anus controls when stool is excreted from the body.

Question 2

Describe the major layers of the walls of the digestive tract & briefly their functions?

Answer 2

Mucous membrane – epithelium, lamina propria, muscularis mucosae.
Secretion/absorption/folding.
Submucosa - Binds mucosa to muscularis externa.
Contains nerves network (ENS).
Muscular Layer (Muscularis externa)
Smooth muscle – patterns of contraction & relaxation.
Important for movement of substances (peristalsis & segmentation).
Serosa - Membrane allowing attachment to abdominal walls.

Question 3

Explain the 6 main digestive functions?

Answer 3

ingestion
mechanical digestion, chemical digestion, absorption,
reabsorption, and defecation.

Question 4

What are the two main types of intestinal movement?

Answer 4

Peristalsis
Segmentation

Question 5

Explain the role of the divisions of ANS on digestive control?

Answer 5

Autonomic nervous system has 3 divisions
Sympathetic - fight or flight system, SNS inhibits digestion and increases energy expenditure.
Parasympathetic - “rest and digest” system, the PNS increases digestion and decreases heart rate.
Enteric - Manages how the body digests food.

Question 6

Identify the role and functions of the oral cavity & saliva?

Answer 6

Sensory analysis of material before swallowing.
Tongue
Mechanical processing.
Teeth, tongue and palatal surfaces.
Mastication (chewing).
Lubrication:
Mixing food with mucus and saliva.
Limited digestion:
Mechanical processing
Chemical digestion - carbohydrates & lipids.
Salivary amylase & lingual lipase.
Salivary glands

Question 7

Explain the process of swallowing?

Answer 7

Movement of food from mouth through pharynx and oesophagus

Question 8

Explain the functions of the stomach & how gastric activity is regulated?

Question 9

Explain briefly how we control feelings of hunger and fullness (satiety)?

Question 10

Explain the functions of the pancreas and name the key functions of pancreatic juices?

Question 11

Describe the main functions of the liver?

Question 12

What is the role of bile in the digestive system?

Question 13

Explain the main functions of the gallbladder?

Question 14

Describe the small intestine functions and anatomy?

Question 15

What are the classes of digestive enzymes?

Question 16

Can you describe the basic steps involved in the digestion and absorption of the key nutrients?

Question 17

How does the large intestine’s structure differ from the small intestine?

Question 18

What are the main functions of the large intestine?

Question 19

Can you describe the two final stages of digestion (mechanical and chemical) that take place in the large intestine?

Question 20

Describe the defecation reflex and why it is necessary?