Grand Tour of The Alimentary Canal

Question 1

What does the GI tract consist of?

Answer 1

Hollow organs in a long, twisting tube from the mouth to the anus

Question 2

What organs are the accessory organs of the GI tract?

Answer 2

Salivary Glands
Liver
Pancreas
Gallbladder

Question 3

What are the main functions of the digestive system?

Answer 3

Digestion
Absorption
Secretion
Motility

Question 4

Explain Digestion

Answer 4

Breaking down of food we eat into simple substances that out bodies can absorb

Question 5

What is digestive absorption?

Answer 5

Passage of end products of digestion from gastrointestinal tract into the blood and lymphatic vessels

Question 6

Explain secretion

Answer 6

Process of which substances are produced and discharged from the cell, gland, or organ for a particular function in the organism or for excretion

Question 7

Explain motility

Answer 7

Is the ability of an organism to move independently, using metabolic energy

Question 8

What are the 3 types of salivary glands?

Answer 8

Paroted
Sublingual
Submandibular

Question 9

Describe the function of the mouth

Answer 9

Foodstuffs are broken down by chewing and saliva is added as lubricant

Question 10

Describe the function of the oesophagus

Answer 10

Conduit between mouth and stomach

Question 11

Describe the function of stomach

Answer 11

Digestion of proteins
Foodstuffs reduced to semi-liquid form
Storage
Sterilisation

Question 12

Describe the function of the pancreas

Answer 12

Digestive enzymes for digestion of fats, carbohydrates and proteins

Question 13

Describe the function of the liver

Answer 13

Bile salts for digestion/absorption of fats in small intestine

Question 14

Describe the function of the gallbladder

Answer 14

Stores and concentrates bile

Question 15

Describe the function of the small intestine

Answer 15

Final stages of chemical digestion and nutrient absorption

Question 16

Describe the function of the large intestine

Answer 16

Water absorption
Bacterial fermentation
Formation of faeces

Question 17

Describe the general structure of the alimentary canal

Answer 17

Continuous hollow tube with varying diameter
Usually about 8 metres long
Tube has same structural organisation throughout length

Question 18

What are the 4 distinctive layers of the alimentary canal?

Answer 18

Mucosa
Submucosa
Muscularis externa
Serosa/ adventitia

Question 19

What are the sub layers of the mucosa?

Answer 19

Epithelium
Lamina Propria
Muscularis Muscosae

Question 20

What is the peritoneum?

Answer 20

Is the serous membrane forming the lining of the abdominal cavity

Question 21

Where are the myenteric plexus and submucosal plexus found?

Answer 21

Myenteric - between circular and longitudinal layer of the muscularis
Submucosal - between circular and submucosa

Question 22

What type of epithelium is in the GI tract?

Answer 22

Stratified squamous - mouth, oesophagus and anal canal
Simple columnar - stomach, small and large intestine

Question 23

What are the function of the epithelium in the GI tract?

Answer 23

Barrier separating lumen
Synthesis and secretion of digestive enzymes, hormones and mucus
Absorbs products

Question 24

Describe the lamina propria

Answer 24

Loose CT - glands, blood and lymph vessels

Question 25

Describe the muscularis mucosae

Answer 25

Thin smooth muscle layer

Question 26

What is the submucosa?

Answer 26

Thick irregular CT which supports mucosa - contains neurons, blood vessels and lymph vessels Glands in oesophagus and duodenum

Question 27

What is the serosa/ adventitia ?

Answer 27

Connective tissue outer layer of the alimentary canal Outside peritoneal cavity - adventitia Inside - serosa

Question 28

Describe the muscularis externa

Answer 28

Two thick layers of smooth muscle - inner is circular and outer is longitudinal Produces motility for peristalsis and segmentation

Question 29

Explain the enteric nervous system

Answer 29

Submucosal and myenteric plexuses which supply independent control of the gut function

Question 30

Describe the nervous control of the alimentary function

Answer 30

Autonomic - long parasympathetic and short ENS reflexes Parasympathetic Sympathetic

Question 31

Explain parasympathetic nerve control of alimentary function

Answer 31

Vagus nerve (X) Salvation is facial and glossopharyngeal Stimulatory function so increases secretion and motility

Question 32

Explain sympathetic nerve control of the alimentary function

Answer 32

Splanchnic nerve Inhibitory so decreases secretion and motility

Question 33

What organs does the celiac trunk supply?

Answer 33

Stomach Small intestine Pancreas Liver

Question 34

What organs does the superior mesenteric artery supply?

Answer 34

Small intestine Caecum Ascending colon Transverse colon

Question 35

What organs does the inferior mesenteric artery supply?

Answer 35

Descending colon Sigmoid colon Rectum

Question 36

What vein controls is the venous drainage of stomach?

Answer 36

Gastric veins

Question 37

What vein controls venous drainage of pancreas?

Answer 37

Splenic veins

Question 38

What does the superior mesenteric vein drain?

Answer 38

Small intestine Caecum Ascending colon Transverse colon

Question 39

What does the inferior mesenteric vein drain?

Answer 39

Descending colon Sigmoid colon Rectum

Question 40

Describe the venous drainage from the GI tract

Answer 40

Gastric, Splenic, superior mesenteric and inferior mesenteric veins all drain to hepatic portal vein Then hepatic vein joining circulation at liver then inferior vena cava