Body Log Session 9

Question 1

What are the different layers of the gut wall?

Answer 1

Mucosa
submucosa
External muscle layer (muscularis externae)
Serosa (outermost)

Question 2

What are the layers of the mucosa of the gut wall?

Answer 2

Muscularis mucosae
Lamina propria
Epithelium

Question 3

What is the mucosa of the gut wall?

Answer 3

Lines the lumen

Question 4

What is the submucosa of the gut wall?

Answer 4

A layer of connective tissue bearing glands, arteries, veins and nerves

Question 5

What makes up the external muscle of the gut wall?

Answer 5

Muscularis external has 2 layers of smooth muscle

• Outer longitudinal layer
• Inner circular layer

Question 6

What is the function of the muscularis externa?

Answer 6

Creates successive peristaltic waves to move luminal contents along the gut

Question 7

What are the histological differences in the appearance of the inner circular layer and the outer longitudinal layer of the muscularis externa?

Answer 7

Inner circular - nuclei in the centre of cells

Outer longitudinal - cigar shaped nuclei

Question 8

What is the serosa made of?

Answer 8

Outermost covering of simple squamous epithelium (mesothelium) + a thin layer of adjacent connective tissue

Question 9

Describe the control in the upper end of the oesophagus?

Answer 9

Voluntary control - some striated skeletal muscle

Question 10

Describe the control in the lower end of the oesophagus?

Answer 10

Involuntary control (solely smooth muscle)

Question 11

Describe the epithelium that is found in the oesophageal mucosa?

Answer 11

Stratified squamous non keratinised (withstands abrasion)

Question 12

What are rugae and where are they found?

Answer 12

Found in the stomach and are folds of gastric mucosa forming longitudinal ridges in empty stomach

Question 13

What type of epithelium lines a villus of the small intestine?

Answer 13

Simple columnar epithelium