Grand tour of the alimentary canal

Question 1

What are the 4 main functions of the digestive system?

Answer 1

digestion, secretion, absorption and motility

Question 2

What are the 2 requirements for digestion?

Answer 2

Aqueous environment and enzymes

Question 3

What organ does ALL of the gut circulation pass through?

Answer 3

Liver

Question 4

Name the 3 pairs of salivary glands

Answer 4

Parotid, submandibular and sublingual

Question 5

What is the lubricant for breakdown of food?

Answer 5

Saliva

Question 6

What is the length of the alimentary canal from oesophagus to rectum?

Answer 6

8m

Question 7

What are the 4 layers found in the alimentary canal wall?

Answer 7

Mucosa, submucosa, muscularis externa and adventitia/serosa

Question 8

What are the 3 layers of the mucosa?

Answer 8

Epithelium, lamina propria and muscularic mucosae

Question 9

What is the lamina propria?

Answer 9

Connective tissue fo rsupport

Question 10

Explain what the difference is between addventita and serosa

Answer 10

Advetitia is the outermost layer of the canal wall located outside the peritoneal cavity ( above the diaphragm) whereas serosa is the exact same but found inside the peritoneal cavity

Question 11

What is the muscularis externa important for?

Answer 11

Motility

Question 12

Where are the 2 locations of submucosal glands?

Answer 12

Oesophagus and duodenum

Question 13

What do the submucosal glands in the 2 locations secrete?

Answer 13

Oesophagus = mucus
duodenum = bicarbonate

Question 14

What are the 2 muscular layers forming the muscularis externa?

Answer 14

Circumferential and longitudinal layer

Question 15

What do the circumferential and longitudinal muscle layers control?

Answer 15

Circumferential = diameter
Longitudinal = length of the tube

Question 16

What plexus is found between the submucosa and circular muscle layer?

Answer 16

Submucosal plexus

Question 17

What plexus is found between the 2 muscular layers?

Answer 17

Myenteric plexus

Question 18

What do the submucosal and myenteric plexus form?

Answer 18

The enteric nervous system (ENS)

Question 19

What kind of epithelium lines the mouth,oesophagus and anal canal? Why?

Answer 19

Stratified squamous - for solid material

Question 20

What kind of epithelium lines the stomach and intestines? Why?

Answer 20

Simple columnar - for diffusion

Question 21

What 3 processes occur in the epithelium?

Answer 21

Secretion, absorption and synthesis

Question 22

What structures are found in the lamina propria?

Answer 22

Lymph and blood vessels, glands

Question 23

What does the submucosa support?

Answer 23

Mucosa and the neurones and blood+lymphatic vessels

Question 24

What do the neurons in the submucosa form?

Answer 24

Submucosal plexus

Question 25

What does the adventitia attach the oesophagus and rectum to?

Answer 25

Surrounding structures

Question 26

What does the serosa surround?

Answer 26

Stomach and intestines

Question 27

What nerve controls parasympathetic gut function? What cranial nerve is this?

Answer 27

Vagus - 10

Question 28

What nerves control parasympathetic salivation? Why?

Answer 28

Facial(7) and glossopharyngeal (4) as vagus does not innervate the head and neck

Question 29

What nerve controls sympathetic innervation of gut function?

Answer 29

Splanchnic

Question 30

Explain sympathetic and parasympathetic in terms of inhibitory and stimulatory

Answer 30

Parasympathetic - stimulatory ALWAYS

sympathetic - inhibitory EXCEPT salivation

Question 31

What 3 arteries does the celiac trunk give off?

Answer 31

Splenic, common hepatic and left gastric

Question 32

What is the arterial supply of the gut?

Answer 32

Celiac trunk, superior and inferior mesenteric arteries

Question 33

Give 1 structure that each of the 3 gut arteries supplies

Answer 33

Celiac - stomach superior - ascending colon

inferior - sigmoid colon

Question 34

What vein does the stomach drain into?

Answer 34

Gastric veins

Question 35

What vein does the pancreas drain into?

Answer 35

Splenic veins

Question 36

What 4 veins drain into the hepatic portal vein?

Answer 36

Gastric, splenic, inf. and sup. mesenteric veins

Question 37

Explain the difference between the hepatic portal and hepatic vein

Answer 37

The hepatic portal vein drains to the liver and the hepatic vein is from the liver draining into the IVC

Question 38

Ultimately what vein do all the veins drain into?

Answer 38

The IVC

Question 39

What mixes with the hepatic portal vein in the liver?

Answer 39

Hepatic artery