Grand Tour of the Alimentary Canal 13092019

Question 1

What are the four functions of the digestive system?

Answer 1

1) Digestion
2) Secretion
3) Absorption
4) Motility

Question 2

Describe the organs / path included in the digestive system

Answer 2

Mouth 
Oesophagus 
Stomach 
Pancreas 
Gall Bladder 
Duodenum 
Small Intestine 
Large Intestine 
Sigmoid Colon 
Rectum 
Anal Canal

Question 3

What does the pancreas digest?

Answer 3

Fats, carbohydrates and protein

Question 4

In relation to the processes of digestion, secretion, absorption and motility, what process occurs in the mouth. Describe how the structure / anatomy of the mouth aids the relevant process.

Answer 4

The mouth is involved in the mechanical disruption of food. As well as this, the introduction of saliva acts as a lubricant. The introduction of amylase from 2 pairs of salivary glands also aids in the breakdown of complex carbohydrates.

Question 5

In relation to the processes of digestion, secretion, absorption and motility, what processes occur in the stomach. Describe how the structure / anatomy of the mouth aids the relevant process.

Answer 5

The bulk of digestion occurs in the stomach via the secretion of concentrated HCL

The stomach also acts as a storage organ for food - if we digested everything at once then osmolarity would increase rapidly - causing water to be drawn out of our tissues

the process of sterilisation also occurs in the stomach.

Question 6

What does the pancreas do?

Answer 6

Secretes enzymes that aid the digestion of fats, carbohydrates and protein

Question 7

What does the (liver) do?

Answer 7

Produces bile salts for the emulsification of fats in the small intestine

Question 8

In relation to the processes of digestion, secretion, absorption and motility, what processes occur in the stomach. Describe how the structure / anatomy of the mouth aids the relevant process.

Answer 8

Final stages of digestion and nutrient absorption - carbohydrates and protein

Question 9

What happens in the large intestine?

Answer 9

Water is absorbed. Bacterial fermentation occurs and faeces are formed.

Question 10

What does the gall bladder do?

Answer 10

Stores and concentrates bile

Question 11

What does the small intestine do?

Answer 11

Final stages of digestion occur here and nutrients are absorbed

Question 12

What does the stomach do?

Answer 12

Stores, digests and sterilises

Question 13

What are the histological layers of the gut tube?

Answer 13

Mucosa
Submucosa
Muscularis Externa
Serosa / Adventitia

Question 14

What are the layers of the mucousa of the gut tube?

Answer 14

Epithelium
Lamina propria
Muscularis mucousae

Question 15

What layer of the gut tube produces gut motility?

Answer 15

Muscualris externa

Question 16

What two kinds of muscularis externa are present?

Answer 16

Round and longitudinal

Question 17

What surrounds the muscularis externa?

Answer 17

A dense myenteric neuronal network

Question 18

What kind of epithelium is found in the mouth, oesophagus and anal canal?

Answer 18

stratified squamous epithelium

Question 19

What kind of epithelium is found in the stomach, small and large intestines?

Answer 19

Simple columnar epithelium

Question 20

What is found in the submucosa?

Answer 20

A dense neuronal network form the parasympathetic nervous system called the Meisinners Plexus

Glands that in the oesophagus secret mucus and in the duodenum secrete bicarbonate

Question 21

What tissue is found in the submucosa?

Answer 21

dense irregular connective tissue

Question 22

Serosa is found inside or outside the peritoneal cavity

Answer 22

inside

Question 23

What does the serosa do?

Answer 23

Surrounds the stomach and small intestine

Question 24

What does the adventitia do?

Answer 24

attached oesophagus and rectum to surrounding structures

Question 25

Adventitia is found inside or outside the peritoneal cavity

Answer 25

Outside

Question 26

What plexus controls the sub-mucosa?

Answer 26

Heisselbach’s plexus (para)

Question 27

What plexus controls the muscularis externa?

Answer 27

Auerbach’s plexus (ENS)

Question 28

What parasympathetic nerve controls the digestive system?

Answer 28

The vagus X

Question 29

What nerve controls salvation?

Answer 29

Facial VII and Glossopharangeal IX

Question 30

What does the celiac artery feed?

Answer 30

Foregut - stomach, liver, pancreas, small intestine

Question 31

what does the superior mesenteric artery feed?

Answer 31

Midgut - small intestine, ascending colon, transverse colon and cecum

Question 32

what does the inferior mesenteric artery feed?

Answer 32

Hindgut - descending colon, sigmoid colon & rectum

Question 33

Describe the venous drainage of the small intestine, ascending colon & transverse colon

Answer 33

drainage into the superior mesenteric vein - into the hepatic portal vein - into the portal vein - into the inferior vena cava

Question 34

Describe the venous drainage of the descending colon, sigmoid colon & rectum

Answer 34

drainage into the inferior mesenteric vein - into the hepatic portal vein - into the portal vein - into the inferior vena cava

Question 35

What vein drains the stomach?

Answer 35

Gastric vein

Question 36

What vein drains the pancreas?

Answer 36

Splenic vein

Question 37

Are the intestines and liver in series or parallel?

Answer 37

Series