Lecture 3 Grand Tour of the Alimentary Canal

Question 1

Functions of the digestive system

Answer 1

Digestion
Secretion
Absorption
Motility

Question 2

Function of the mouth

Answer 2

Foodstuffs broken down by chewing; saliva added as lubricant

Question 3

Function of oesophagus

Answer 3

Conduit between mouth and stomach

Question 4

Function of stomach

Answer 4

Digestion of proteins; foodstuffs reduced to liquid form; storage and sterilisation

Question 5

Function of Liver

Answer 5

Bile salts for digestion/absorption of fats in small intestine

Question 6

Function of gallbladder

Answer 6

Stores and concentrate bile

Question 7

Function of Small intestine

Answer 7

Final stages of chemical digestion and nutrient absorption

Question 8

Function of large intestine

Answer 8

Water absorption, bacterial fermentation and formation of faeces

Question 9

Length of oesophagus to rectum

Answer 9

8meteres

Question 10

Four distinct layers of alimentary canal

Answer 10

Mucosa
Submucosa
Muscularis externa
Serosa/adventitia

Question 11

Layers of mucosa

Answer 11

Epithelium
Lamina propria
Muscularis mucosa

Question 12

What does the submucosa contan

Answer 12

Blood and nerve supply

Submucosa plexus

Question 13

Function and structure of muscularis externa

Answer 13

Motility
2 concentric layers
Innermost is circular (contracts and narrows)
Outermost os longitudinal (contracts and elongates0

Question 14

Whats sits between muscle layers of muscularis externa

Answer 14

Myenteric plexus

Question 15

What is the serosa/adventitia layer

Answer 15

Connective tissue covering

Question 16

Epithelium in mouth, oesophagus and anal canal

Answer 16

Stratifies squamous

Question 17

Epithelia in stomach, small & large intestine

Answer 17

Simple columnar

Question 18

The submucosa contain =s what network neurones

Answer 18

Submucosal (Meissner’s) plexus which is parasympathetic

Question 19

Submucosal glands are located where

Answer 19

Oesophagus and duodenum

Question 20

Outside of peritoneum where does the adventitia attach to

Answer 20

oesophagus and rectum

Question 21

Inside the peritoneum where does the serosa attach to

Answer 21

stomach, small intestine and large intestine

Question 22

Whats the name of the plexus between the circular muscle and longitudinal muscle in the muscularis externa

Answer 22

Myenteric (Auerbach’s) plexus

Question 23

What movements do the muscularis externa control

Answer 23

Segmentation and peristalsis

Question 24

Autonomic control of the alimentary system

Answer 24

Long (parasympathetic) and short ENS reflexes

Question 25

Parasympathetic nerve and function

Answer 25

Vagus nerve (X) except salivation
Facial (VII) and glossopharyngeal (IX)
Stimulatory: increases secretion and motility

Question 26

Sympathetic nerve

Answer 26

Splanchnic nerve
Inhibitory except for salivation
Decrease secretion and motility

Question 27

Venous drainage of stomach

Answer 27

Gastric veins

Question 28

Venous drainage of pancreas

Answer 28

Splenic vein

Question 29

Venous drainage of midgut

Answer 29

Superior mesenteric vein

Question 30

Venous drainage of hind gut

Answer 30

Inferior mesenteric vein

Question 31

Where do the veins of the GI tract eventually drain into

Answer 31

Hepatic portal vein
Hepatic vein
IVC