Overview of the Digestive Tract and Peritoneal Coverings

Question 1

What are the 5 phases of digestion?

Answer 1

1 - Ingestion.

2 - Fragmentation.

3 - Digestion.

4 - Absorption.

5 - Elimination.

Question 2

Where does the oral cavity extend from / to?

Answer 2

From the lips to the oropharynx.

Question 3

What are the two regions of the oral cavity?

Answer 3

The vestibule and the oral cavity proper.

Question 4

What are the boundaries of the vestibule of the oral cavity?

Answer 4

Externally: Lips and cheeks (buccinators muscles).

Internally: Teeth and gums.

Question 5

What are the boundaries of the oral cavity proper?

Answer 5

Anteriolaterally: Dental arches.

Floor: Anterior 2/3 tongue, mylohyoid muscles and geniohyoid muscles.

Roof: Hard and soft palate.

Posteriorly: Oropharyngeal isthmus.

Question 6

List 4 intrinsic muscles of the tongue.

Answer 6

1 - Superior longitudinal.

2 - Vertical.

3 - Transverse,

4 - Inferior longitudinal.

Question 7

List 4 extrinsic muscles of the tongue.

Answer 7

1 - Palatoglossus.

2 - Styloglossus.

3 - Hypoglossus.

4 - Genioglossus.

Question 8

Which nerves supply the extrinsic and intrinsic muscles of the tongue?

Answer 8

All muscles are supplied by the hypoglossal (XII) cranial nerve except for the palatoglossus muscle, which is supplied by the vagus (X) nerve.

Question 9

Describe the sensory innervation of the tongue.

Answer 9

Anterior 2/3:

• General sensation by mandibular nerve via lingual nerve.
• Taste sensation by facial nerve via chorda tympani.

Posterior 1/3:
- General and taste sensation via glossopharyngeal nerve.

Question 10

What are the 4 layers of the gut tube?

Answer 10

1 - Mucosa.

2 - Submucosa.

3 - Muscularis externa.

4 - Serosa.

Question 11

Which 4 tissues are contained within the mucosa of the gut tube?

Answer 11

1 - Epithelia.

2 - Basement membrane.

3 - Lamina propria.

4 - Muscularis mucosae.

Question 12

Which 6 tissues are contained within the submucosa of the gut tube?

Answer 12

1 - Connective tissue.

2 - Blood vessels.

3 - Lymphatics.

4 - Autonomic nerves (myenteric and submucosal).

5 - Glands.

6 - Lymphoid tissue.

Question 13

Describe the layers of the muscularis externa.

Where does its innervation come from?

Where is it located?

Answer 13

• Inner = circular.
• Outer = longitudinal.
• Innervation from myenteric plexus.
• Located between layers of blood vessels between the submucosa and serosa.

Question 14

Which 5 tissues are contained within the serosa?

Answer 14

1 - Loose connective tissue.

2 - Blood vessles.

3 - Lymphatics.

4 - Adipose.

5 - Simple squamous epithelium covering.

Question 15

What are the 3 regions of the gut?

Where does each region start and end?

From which arteries is the arterial supply of each of these regions derived?

Answer 15

1 - Foregut:

• Abdominal oesophagus to descending duodenum (D2/4).
• Coeliac artery.

2 - Midgut:

• Descending duodenum (D2/4) to distal 1/3 of transverse colon.
• Superior mesenteric artery.

3 - Hindgut:

• Distal 1/3 of transverse colon to mid anal canal.
• Inferior mesenteric artery.

Question 16

Summarise the venous drainage of the GI tract.

Answer 16

• Foregut: Hepatic portal vein and splenic vein.
• Midgut: Superior mesenteric vein.
• Hindgut: Inferior mesenteric vein.
• Inferior mesenteric vein drains into splenic vein.
• Splenic vein and superior mesenteric vein unite to form the hepatic portal vein.

Question 17

Describe the lymphatic drainage of the foregut.

Answer 17

Lymph drains through coeliac lymph nodes.

Question 18

Describe the lymphatic drainage of the midgut.

Answer 18

Lymph drains through superior mesenteric lymph nodes.

Question 19

Describe the lymphatic drainage of the hindgut.

Answer 19

Lymph drains through inferior mesenteric lymph nodes.

Question 20

Describe the innervation of the foregut.

Answer 20

• Parasympathetic: Vagus nerve.
• Sympathetic: Greater thoracic splanchnic nerves (T6-T10)
• Coeliac plexus.

Question 21

Describe the innervation of the midgut.

Answer 21

• Parasympathetic: Vagus nerve.
• Sympathetic: Lesser thoracic splanchnic nerves (T9-T11,L1).
• Superior mesenteric plexus.

Question 22

Describe the innervation of the hindgut.

Answer 22

• Parasympathetic: Pelvic splanchnic nerves (S2-S4).
• Sympathetic: Upperlumbar splanchnic nerves (L1-L2).
• Inferior mesenteric plexus.

Question 23

Where does the oesophagus extend from / to?

Answer 23

From the laryngeal pharynx (C6) to the stomach (T11).

Question 24

What are the 3 regions of the oesophagus?

Answer 24

1 - Cervical.

2 - Thoracic.

3 - Abdominal.

Question 25

Which artery supplies the cervical region of the oesophagus?

Answer 25

The inferior thyroid artery.

Question 26

Which artery supplies the thoracic region of the oesophagus?

Answer 26

The descending thoracic aorta.

Question 27

Which artery supplies the abdominal region of the oesophagus?

Answer 27

The left gastric artery.

Question 28

Which vein drains the cervical region of the oesophagus?

Answer 28

The inferior thyroid veins.

Question 29

Which vein drains the thoracic region of the oesophagus?

Answer 29

The azygous veins.

Question 30

Which vein drains the abdominal region of the oesophagus?

Answer 30

The left gastric vein (a tributary of the HPV).

Question 31

Which nerve gives the oesophagus its parasympathetic innervation?

Answer 31

The vagus nerve.

Question 32

Where do the sympathetic fibres that innervate the oesophagus originate?

Answer 32

The cervical and thoracic sympathetic trunk.

Question 33

Which nerve forms the oesophageal plexus? What does the plexus converge into?

Answer 33

The vagus nerve. The anterior and posterior vagal trunks.

Question 34

Which type of epithelium lines the oesophagus? Which condition is characterised by a change in the type of epithelium lining the oesophagus?

Answer 34

- Non keratinised stratified squamous epithelium. | - Barrett's oesophagus / metaplasia (can be caused by GORD).

Question 35

In which layer of the oesophagus are the mucus secreting glands located?

Answer 35

In the submucosa.

Question 36

How does the distribution of skeletal muscle and smooth muscle change down the length of the oesophagus?

Answer 36

- Upper 1/3 is skeletal muscle. - Middle 1/3 is mixed. - Lower 1/3 is smooth muscle.

Question 37

Where is the stomach located?

Answer 37

In the left upper abdomen. *Changes with volume, body position and phase of respiration.

Question 38

What are the 5 regions of the stomach?

Answer 38

1 - Cardia. 2 - Fundus. 3 - Body. 4 - Antrum. 5 - Pylorus.

Question 39

Describe the arterial supply to the stomach.

Answer 39

* All branches of the coeliac artery: * Left gastric artery - lesser curvature. * Splenic artery: - Short gastric arteries - fundus. - Left gastro-omental artery - greater curvature. • Common hepatic artery: - Right gastric artery - lesser curvature. - Gastroduodenal artery - greater curvature.

Question 40

Where do the veins that drain blood from the stomach drain into?

Answer 40

The portal circulation.

Question 41

List the regions of the duodenum.

Answer 41

- D1 - Superior part. - D2 - Descending part. - D3 - Inferior part. - D4 - Ascending part.

Question 42

What are the two main arteries that supply the duodenum?

Answer 42

The coeliac artery and the superior mesenteric artery.

Question 43

What are the two main veins that drain the duodenum?

Answer 43

- Prepyloric vein. | - Superior and inferior pancreatoduodenal veins.

Question 44

Where is the liver located?

Answer 44

- Spans the right upper quadrant, the epigastrium and the left upper quadrant. - Inferior to the diaphragm.

Question 45

Describe the lymphatic drainage of the liver.

Answer 45

- Coeliac lymph nodes. - Parasternal lymph nodes. - Anterior abdominal wall.

Question 46

List the regions pf the gallbladder.

Answer 46

1 - Fundus. 2 - Body. 3 - Neck. 4 - Cystic duct.

Question 47

Where does the gallbladder lie?

Answer 47

In the gallbladder fossa, on the visceral surface of the liver.

Question 48

List the regions of the pancreas.

Answer 48

1 - Head. 2 - Neck. 3 - Body. 4 - Tail.

Question 49

Where is the pancreas located?

Answer 49

Anterior to the inferior vena cava and abdominal aorta. - Posterior to the stomach .

Question 50

Which molecules trigger the secretion of exocrine secretions of the pancreas?

Answer 50

Secretin and cholecystokinin.

Question 51

What triggers the release of secretin and cholecystokinin?

Answer 51

The presence of food in the duodenum.

Question 52

What is drained by the main pancreatic duct?

Answer 52

The tail, neck and head of the pancreas.

Question 53

Which structures unite to form the hepatopancreatic ampulla? What is the hepatopancreatic ampulla also known as?

Answer 53

- The main pancreatic duct and the common bile duct. | - The ampulla of Vater.

Question 54

What does the hepatopancreatic ampulla open onto?

Answer 54

The major duodenal papilla (D2).

Question 55

What is ERCP used for and what does it stand for?

Answer 55

Enables examination of the pancreatic and bile ducts. Endoscopic retrograde cholangiopancreatography

Question 56

What is the name of the sphincter that surrounds the opening of the hepatopancreatic ampulla?

Answer 56

Sphincter of Oddi (hepatopancreatic sphincter).

Question 57

What is drained by the accessory pancreatic duct?

Answer 57

The head and uncinate process of the pancreas.

Question 58

What does the accessory pancreatic duct open onto?

Answer 58

The minor duodenal papilla.

Question 59

List all cells found in the islets of Langerhan and their secretions.

Answer 59

1 - Alpha - Glucagon. 2 - Beta - Insulin. 3 - Delta - Somatostatin. 4 - PP - Pancreatic Polypeptide.

Question 60

List 4 secretions of acinar cells.

Answer 60

1 - Bicarbonate ions. 2 - Inactive proteases. 3 - Inactive lipases. 4 - Inactive amylase.

Question 61

Where does the jejunum start?

Answer 61

At the duodenojejunal flexure.

Question 62

Where does the ileum end?

Answer 62

At the ileocaecal junction.

Question 63

Describe the arterial supply to the jejunum.

Answer 63

Jejunal arteries (from the superior mesenteric artery).

Question 64

Describe the arterial supply to the ileum.

Answer 64

Ileal arteries and the ileal branch of the ileocolic artery (from the superior mesenteric artery.)

Question 65

What does the large intestine absorb?

Answer 65

Water and electrolytes.

Question 66

List the 9 segments of the large intestine in order, including flexures.

Answer 66

1 - Caecum (and appendix). 2 - Ascending colon. 3 - Hepatic / right colonic flexure. 4 - Transverse colon. 5 - Splenic / left colonic flexure. 6 - Descending colon. 7 - Sigmoid colon. 8 - Rectum. 9 - Anal canal.

Question 67

What are taeniae coli?

Answer 67

Condensed longitudinal muscle that run the length of the large intestine.

Question 68

Which artery is the source of the large intestine's arterial supply?

Answer 68

The superior mesenteric artery.

Question 69

Which artery supplies the appendix? Which artery is this a branch of?

Answer 69

- The appendicular artery. | - A branch of the ileocolic artery.

Question 70

Which artery supplies the caecum? Which artery is this a branch of?

Answer 70

- Anterior and posterior caecal arteries. | - Branches of the ileocolic artery.

Question 71

Which artery supplies the ascending colon? Which artery is this a branch of?

Answer 71

- The right colic artery. | - The superior mesenteric artery.

Question 72

Which artery is the ileocolic artery a branch of?

Answer 72

The superior mesenteric artery.

Question 73

Which artery supplies the proximal 2/3 of the transverse colon? Which artery is this a branch of?

Answer 73

- The middle colic artery. | - The superior mesenteric artery.

Question 74

Which artery supplies the distal 1/3 of the transverse colon and descending colon? Which artery is this a branch of?

Answer 74

- The left colic artery. | - The inferior mesenteric artery.

Question 75

Which arteries supply the sigmoid colon? Which arteries are these a branch of?

Answer 75

- Sigmoid arteries. | - The inferior mesenteric artery.

Question 76

Which artery supplies the upper rectum? Which artery is this a branch of?

Answer 76

- The superior rectal artery. | - The inferior mesenteric artery.

Question 77

Which artery joins the branches of the superior and inferior mesenteric arteries?

Answer 77

The marginal artery.

Question 78

Where does the anal canal extend from and to?

Answer 78

From the rectal ampulla to the anus.

Question 79

How many sphincters does the anal canal have? What are they called and how do they differ?

Answer 79

- 2: The internal and external anal sphincters. | - The internal anal sphincter is smooth muscle whereas the external anal sphincter is skeletal muscle.

Question 80

Which arteries supply the rectum and anal canal?

Answer 80

The superior, middle and inferior rectal arteries.

Question 81

Where is the peritoneal cavity?

Answer 81

Between the parietal and visceral peritoneum.

Question 82

What are the divisions of the peritoneal cavity?

Answer 82

The lesser and greater sacs.

Question 83

Where does the greater sac of the peritoneal cavity extend from and to?

Answer 83

From the diaphragm into the pelvic cavity.

Question 84

What is the omental foramen?

Answer 84

The foramen between the greater sac and the lesser sac of the peritoneum.

Question 85

What are the functions of the greater omentum?

Answer 85

- To attach the greater curvature of the stomach (and D1) to the transverse colon. - To seal off and localise infection.

Question 86

Which vessels supply the greater omentum?

Answer 86

Right and left gastro-omental vessels.

Question 87

What are the functions of the lesser omentum? Which ligaments comprise the lesser omentum?

Answer 87

- To attach the lesser curvature of the stomach (and D1) to the inferior liver. - To seal off and localise infection. - Hepatogastric ligament (stomach). - Hepatoduodenal ligament (D1).

Question 88

What is the function of mesentery?

Answer 88

To attach viscera to the posterior abdominal wall.

Question 89

What does mesentery carry?

Answer 89

Blood vessels, nerves and lymphatics.

Question 90

What is the function of peritoneal ligaments?

Answer 90

- To connect organs to other organs and to the body wall. | - Peritoneal ligaments form part of the omentum.