The Alimentary Canal

Question 1

What are the 4 basic functions of the digestive system?

Answer 1

Digestion
Secretion
Absorption
Motility

Question 2

What is the basic order of organs in the alimentary system? (8)

Answer 2

Mouth > Esophagus > Stomach > Pancreas > Liver > Gallbladder > Small intestine > Large intestine

Question 3

What is the basic function of the mouth? (2)

Answer 3

Breakdown foodstuff (chewing)
Lubricate foodstuff (saliva)

Question 4

What is the basic function of the Oesophagus?

Answer 4

Transport foodstuff between the mouth and stomach

Question 5

What is the basic function of the Stomach? (4)

Answer 5

Digestion of proteins
Liquidation of foodstuffs
Storage
Sterilisation

Question 6

What is the basic function of the Pancreas?

Answer 6

To produce digestive enzymes for carbohydrates, fats and proteins

Question 7

What is the basic function of the Liver?

Answer 7

To produce bile salts for the digestion/absorption of fats in the small intestine

Question 8

What is the basic function of the Gallbladder?

Answer 8

To store and concentrate bile

Question 9

What is the basic function of the small intestine?

Answer 9

Provides final stages of chemical digestion and nutrient absorption

Question 10

What is the basic function of the large intestine? (3)

Answer 10

Water absorption
Fermentation of bacteria
Formation of faeces

Question 11

What are the 4 distinctive layers of the alimentary canal?

Answer 11

Mucosa
Submucosa
Muscularis externa
Serosa or adventitia

Question 12

What are the 3 layers of the mucosa? (from innermost to outermost)

Answer 12

Epithelium
Lamina propria
Muscularis musosae

Question 13

What type of mucosa epithelium is present in the following areas: Mouth, esophagus, anal canal?

Answer 13

Stratified squamous

Question 14

What type of mucosa epithelium is present in the following areas: Stomach, small & large intestine?

Answer 14

Simple columnar

Question 15

What are the 3 functions of the mucosa epithelium?

Answer 15

Separate lumen of canal from the body
Abdsorb products of digestion
Synthesise and secrete digestive enzymes, hormones and mucus

Question 16

What is the Lamina propria made of?

Answer 16

Loose connective tissue

Question 17

What is the muscularis mucosae made from?

Answer 17

A thin smooth muscle layer

Question 18

In which layer of the mucoasa could glands and blood/lymph vessels be found?

Answer 18

Lamina propria

Question 19

What type of tissue is the submucosa made from?

Answer 19

Thick, irregular connective tissue

Question 20

What is contained within the submucosa? (3)

Answer 20

Neurones
Blood vessels
Lymphatic vessels

Question 21

What is the name of the neurone network formed in the submucosa and what type of neurone network is it?

Answer 21

Submucosal plexus - parasympathetic network

Question 22

What additional feature is contained in the submucosa of only the esophagus and duodenum?

Answer 22

Submucosal glands

Question 23

What are the 2 cocentric thick layers of smooth muscle in the Muscularis Externa?

Answer 23

Circular muscle - inner layer

Longitudinal muscle - outer later

Question 24

What is the function of the circular muscle in the Muscularis Externa?

Answer 24

To constrict the lumen

Question 25

What is the function of the longitudinal muscle in the Muscularis Externa?

Answer 25

Shortens the tube

Question 26

What is the overall function of the the 2 layers of the Muscularis Externa?

Answer 26

To produce motility (peristalsis, segmentation)

Question 27

What plexus lies between the circular and longitudinal muscle?

Answer 27

Myenteric Plexus

Question 28

What do the submucosal and myenteric plexuses make up together?

Answer 28

The enteric nervous system (ENS)

Question 29

What is the funciton of the ENS (enteric nervous system)?

Answer 29

Independent control of gut function

Question 30

What type of tissue is the serosa/adventitia made from?

Answer 30

Connective tissue

Question 31

Which layer (serosa or adventitia) attaches outside the peritoneal cavity and what does it do?

Answer 31

Adventitia - attaches oesophagus and rectum to surrounding structures

Question 32

Which layer (serosa or adventitia) attaches inside the peritoneal cavity and what does it do?

Answer 32

Serosa - surround the stomach, small intestine and large intestine

Question 33

What are the (a) Long and (b) Short reflexes of the nervous control of alimentary function?

Answer 33

(a) parasympathetic | (b) Enteric Nervous System

Question 34

Which nerve innervates the parasympathetic control (except salivation) of alimentary function?

Answer 34

Vagus nerve (X)

Question 35

What effect does the parasympathetic system have on alimentary function? (2)

Answer 35

It stimulates secretion and motility

Question 36

Which nerve innervates the sympathetic control of alimentary function?

Answer 36

Splanchnic nerve

Question 37

What effect does the sympathetic system have on alimentary function? (3)

Answer 37

Inhibits secretion and motility | Stimulates salivation

Question 38

Which 2 nerves innervate parasympathetic salivation in alimentary function?

Answer 38

Facial (VII) | Glossopharyngeal (IX)

Question 39

What are the 3 main branches of the D.Aorta for the arterial supply of the GI tract?

Answer 39

Celiac trunk Superior mesenteric artery Inferior mesenteric artery

Question 40

What 4 organs does the celiac trunk supply?

Answer 40

Stomach Small intestine Pancreas Liver

Question 41

What 4 organs does the Superior mesenteric artery supply?

Answer 41

Small intestine Caecum Ascending colon Transverse colon

Question 42

What 3 organs does the inferior mesenteric artery supply?

Answer 42

Descending colon Sigmoid colon Rectum

Question 43

Which veins does the stomach drain into?

Answer 43

Gastric veins

Question 44

Which vein does the pancreas drain into?

Answer 44

Splenic vein

Question 45

Which vein does the small intestine, caecum, ascending colon and transverse colon drain into?

Answer 45

Superior mesenteric vein

Question 46

Which vein does the rectum, descending colon and sigmoid colon drain into?

Answer 46

Inferior mesenteric vein

Question 47

Which vein do all the smaller GI veins drain into before going through the hepatic vein into the IVC?

Answer 47

Hepatic portal vein