Gastrointestinal System

Question 1

Identify the structures of the gastrointestinal tract

Answer 1

Mouth
Pharynx
Oesophagus
Stomach
Small Intestine 
Large Intestine

Question 2

Identify the accessory organs of the GI tract

Answer 2

Teeth

Tongue

Question 3

Identify the glandular organs of the GI tract

Answer 3

Salivary glands
Liver
Gallbladder
Pancreas

Question 4

The walls of the GI tract consists of four layers, what are they called?

Answer 4

Mucosa
Submucosa
Muscularis externa
Serosa

Question 5

What are the properties of the mucosa layer?

Answer 5

• Divided into surface epithelium and lamina propria

- Thin smooth muscle layer

Question 6

What are the properties of the submucosa layer?

Answer 6

• Connective tissue with extensive vascularisation, nervous supply and lymphatics

Question 7

What are the properties of the muscularis externa?

Answer 7

• Muscle layer divided into circular and longitudinal muscle that moves food through tract by ‘peristalsis’

Question 8

What are the properties of the serosa?

Answer 8

• Outermost layer of thin connective tissue surrounds tract and anchors tract to abdominal wall

Question 9

There are three sets of salivary glands in the oral cavity, where are they and what are they called?

Answer 9

▫ Parotid - side of mouth
▫ Sublingual - below tongue
▫ Submandibular - floor of mouth

Question 10

What are teeth primarily made of?

Answer 10

Dentin

Question 11

What cavity contains blood vessels and nerves in teeth?

Answer 11

Central pulp cavity

Question 12

Identify the 6 functional divisions of the GI tract

Answer 12

• Ingestion
• Secretion
• Mixing & propulsion
• Digestion
• Abosrption
• Defecation

Question 13

Describe the function of the stomach

Answer 13

Mechanical and chemical digestion occurs

Question 14

Describe the function of the small intestine

Answer 14

• Digestion continues in small intestine

- Most absorption occurs in small intestine

Question 15

Describe the function of the large intestine

Answer 15

Large intestine site of final water absorption and conversion of chyme to faeces

Question 16

Define peristalsis

Answer 16

• Series of contractions that moves bolus down GI tract

Question 17

What chemical is released by parietal cells?

Answer 17

• Hydrochloric acid

Question 18

What chemical is released by chief cells?

Answer 18

• Pepsinogen

Question 19

What is the function of hydrochloric acid in the stomach?

Answer 19

• Kills most microorganisms
• Denatures (unfolds) proteins
• Breaks down plant cell walls
• Activates pepsinogen to form pepsin
• Promotes the flow of bile and pancreatic juice

Question 20

Pepsinogen forms pepsin which does what?

Answer 20

Breaks down proteins

Question 21

Gastric lipase breaks down what substance?

Answer 21

Triglycerides

Question 22

What is the function of the pancreas?

Answer 22

• Produces (about 1-1.5L daily) digestive enzymes and buffers known as pancreatic juice
• Helps digestion and raises pH of chyme

Question 23

What is the function of the liver?

Answer 23

• Synthesis and release of bile
• Bile emulsifies lipid droplets – makes them smaller
• Allows lipases to work effectively
• Promotes absorption of lipids by intestinal epithelium

Question 24

What percentage of nutrients are absorbed in the small intestine?

Answer 24

90%

Question 25

How are nutrients absorbed into the blood?

Answer 25

• Nutrients pass into epithelial cells of intestinal villi

- Transferred to blood and lymph for distribution

Question 26

Of the 9.3L of water that is ingested by the small intestine what amount is lost through faeces?

Answer 26

100ml