Grand Tour of Alimentary Canal

Question 1

Functions of digestive system

Answer 1

Digestion
Secretion
Absorption
Motility

Question 2

What type of environment is needed for digestion?

Answer 2

Aqueous

Question 3

Function of mouth

Answer 3

Foodstuffs broken down by chewing

Question 4

What is added as a lubricant to the mouth to break down foodstuffs?

Answer 4

Saliva

Question 5

Function of oesophagus

Answer 5

Conduit between mouth and stomach

Question 6

Functions of the stomach

Answer 6

Digestion of proteins
Foodstuffs reduced to liquid form
Storage
Sterilisation

Question 7

Functions of pancreas

Answer 7

Digestive enzymes for digestion of fats, carbohydrates and proteins

Question 8

Function of liver

Answer 8

Bile salts for digestion/absorption of fats in small intestine

Question 9

Function of the gallbladder

Answer 9

Stores and concentrates bile

Question 10

Function of small intestine

Answer 10

Final stages of chemical digestion and nutrient absorption

Question 11

Functions of large intestine

Answer 11

Water absorption
Bacterial fermentation
Formation of faeces

Question 12

How much of live bacteria is found in the large intestine?

Answer 12

1kg

Question 13

How long is the tube from oesophagus to rectum?

Answer 13

Approx. 8 metres

Question 14

4 distinctive layers/tunics of the wall

Answer 14

Mucosa
Submucosa
Muscularis externa
Serosa/Adventitia

Question 15

Layers of the mucosal layer

Answer 15

1. Epithelium
2. Lamina propria
3. Muscularis mucosae

Question 16

Where does all the motility of the canal come from?

Answer 16

Muscularis externa

Question 17

What does the serosa/adventitia make the intestine look like?

Answer 17

Shiney

Question 18

Two layers of the Muscularis externa

Answer 18

Circular muscle layer

Longitudinal muscle layer

Question 19

What does the serosa consist of?

Answer 19

Connective tissue

Question 20

Epithelium of the mouth

Answer 20

Stratified squamous

Question 21

Epithelium of the stomach

Answer 21

Simple columnar

Question 22

Epithelium of the oesophagus

Answer 22

Stratified squamous

Question 23

Epithelium of the small and large intestines

Answer 23

Simple columnar

Question 24

Epithelium of the anal canal

Answer 24

Stratified squamous

Question 25

Function of mucosa layer (depending on location)

Answer 25

Barrier separating lumen of alimentary canal from the body
Synthesis and secretion of digestive enzymes, hormones, mucus
Absorbs the products of digestion

Question 26

What is the submucosal layer?

Answer 26

Thick, irregular connective tissue

Question 27

What does the submucosal layer do?

Answer 27

Supports the mucosa

Question 28

What does the submucosa contain?

Answer 28

Neurones
Blood vessels
Lymphatic vessels

Question 29

What do the neurones in the submucosa form?

Answer 29

Extensive network

- Submucosal (Meissner’s plexus) = parasympathetic

Question 30

Where are submucosal glands found?

Answer 30

Oesophagus

Duodenum

Question 31

What does the submucosal gland in the oesophagus secrete?

Answer 31

Mucus

Question 32

What does the submucosal gland in the duodenum secrete?

Answer 32

Bicarbonate

Question 33

Function of the inner circular layer of the Muscularis externa

Answer 33

Constricts lumen

Question 34

Function of the outer circular muscle layer/longitudinal muscle

Answer 34

Shortens tube

Question 35

Function of Muscularis externa

Answer 35

Peristalsis

Segmentation

Question 36

What is found between circular and longitudinal muscle layer?

Answer 36

Myenteric (Auerbach’s plexus)

Question 37

What provides independent control of gut function?

Answer 37

Submucosal and myenteric plexus

Question 38

What are the submucosal and myenteric plexuses part of?

Answer 38

Enteric nervous system

Question 39

Function of serosa/adventitia outside peritoneal cavity

Answer 39

Attaches oesophagus and rectum to surrounding structures

Question 40

Function of serosa/adventitia inside peritoneal cavity

Answer 40

Surrounds stomach, small intestine and large intestine

Question 41

How many pairs of salivary glands are there?

Answer 41

3

Question 42

Autonomic control of GI tube

Answer 42

Long (parasympathetic)

Short (ENS) Reflexes

Question 43

Parasympathetic control of gut tube is via what?

Answer 43

Vagus nerve CN X

Question 44

What does parasympathetic nerve activity do to the gut tube?

Answer 44

STIMULATORY

• increase in secretion
• increase in motility

Question 45

What is sympathetic supply to the gut tube via?

Answer 45

Splanchnic nerve

Question 46

What does sympathetic activity do to the gut tube?

Answer 46

INHIBITORY
- Decrease in secretion 
- decrease in motility 
EXCEPT SALVATION
- increase in salvation

Question 47

Branches of arterial supply to the GI tract off the descending abdominal aorta

Answer 47

Coeliac trunk
Superior mesenteric artery
Inferior mesenteric artery

Question 48

What is supplied by the coeliac trunk?

Answer 48

Stomach
Small intestine
Pancreas
Liver

Question 49

What is supplied by the superior mesenteric artery?

Answer 49

Small intestine
Caecum
Ascending colon
Transverse colon

Question 50

What is supplied by the inferior mesenteric artery?

Answer 50

Descending colon
Sigmoid colon
Rectum

Question 51

Venous drainage of stomach

Answer 51

Gastric veins

Question 52

Venous drainage of pancreas

Answer 52

Splenic vein

Question 53

What does the superior mesenteric vein drain?

Answer 53

Small intestine
Caecum
Ascending colon
Transverse colon

Question 54

What does the inferior mesenteric drain?

Answer 54

Descending colon
Sigmoid colon
Rectum

Question 55

Where does the gastric, splenic, superior mesenteric and inferior mesenteric veins drain to?

Answer 55

Hepatic portal vein

Question 56

Where does the hepatic portal vein drain to?

Answer 56

Hepatic vein

Question 57

Where does the hepatic vein drain to?

Answer 57

Inferior vena cava