1.1 Purpose Of The Gut

Question 1

Name some accessory organs of the GI tract

Answer 1

Salivary glands
Liver
Gallbladder
Pancreas

Question 2

What are some examples of waste products that the gut needs to expel?

Answer 2

Bilirubin

Cholesterol

Question 3

What are the roles of the gut?

Answer 3

Port of entry 
Mechanically disrupts food 
Temporarily store food
Chemically digest food 
Kill pathogens in food
Move food along tract 
Absorb nutrients 
Eliminate residual waste material

Question 4

Where does mechanical disruption occur?

Answer 4

Mouth/teeth

Stomach

Question 5

What does muscle in the upper area of the stomach do?

Answer 5

Creates basal tone by slow, sustained contractions

Question 6

What does the muscle of the lower stomach do?

Answer 6

Powerful peristaltic contractions that grind the food

Question 7

Why are the contractions of the lower stomach more powerful than the upper stomach?

Answer 7

Has a thicker muscle layer

An additional inner oblique layer of muscle of the muscularis externa

Question 8

How is the stomach a storage facility?

Answer 8

Has temporary folds called rugae

Question 9

Why is it important that receptive relaxation occurs in the stomach?

Answer 9

So intraluminal pressures dont increase

Question 10

Where in the GI tract are there storage facilities?

Answer 10

Stomach

Colon

Question 11

How is the colon evacuated?

Answer 11

Through mass movement

Question 12

What enzymes are present in saliva?

Answer 12

Amylase - starch

Lipase - fats

Question 13

What in the stomach allows chemical digestion?

Answer 13

Acid

Pepsin - protein

Question 14

What allows chemical digestion in the duodenum/jejunum?

Answer 14

Bile

Exocrine pancreas

Question 15

Describe some of the defences of the GI tract against bacteria

Answer 15

Saliva
HCl
Kupffer cells in the liver
Peyers patches for immune surveillance

Question 16

What four types of movement are there in the GI tract?

Answer 16

Peristalsis
Segmentation
Haustral shuttling
Mass movements

Question 17

What structural features of the gut aid absorption?

Answer 17

Length of gut
Folds
Villi and microvilli

Question 18

What are the functions of the mouth?

Answer 18

Physical breakdown of food
Initial digestive enzymes released
Infection control

Question 19

What are the functions of the oesophagus?

Answer 19

Rapid transport of bolus to stomach through thorax

UOS prevents air from entering the GI tract

LOS helps prevent reflux into oesophagus

Question 20

What are the functions of the stomach?

Answer 20

Storage facility 
Product chyme 
- physical and chemical  breakdown, digestion started 
Infection control - HCl
Secrete IF from parietal calls

Question 21

What are the functions of the duodenum?

Answer 21

Neutralisation of chyme

Question 22

Where does the majority of nutrient absorption occur?

Answer 22

Jejunum

Question 23

Where does the majority of water/electrolyte absorption occur?

Answer 23

Mainly ileum

Question 24

Where does bile recirculating occur?

Answer 24

Ileum

Question 25

Where does B12 absorption occur?

Answer 25

Terminal ileum

Question 26

What are the functions of the large bowel?

Answer 26

Final water absorption

Final electrolyte absorption

Question 27

What is the function of the rectum/anus?

Answer 27

Defaecation