Histology

Question 1

Describe the layers of GI tissue:

Answer 1

1. Mucosa
   - epithelium
   - lamina propria
   - muscularis mucosae
2. Submucosa
   - connective tissue
3. Muscularis externa
   - inner layer and outer layer of smooth muscle
   - myenteric ganglia in between
4. Serosa/adventitia
   - connective tissue (adventitia)
   - simple squamous (serosa)

Question 2

What are the specalised cells within the stomach?

Answer 2

1. Parietal cells
   - synthesise and secrete HCl
   - produce intrinsic factor
2. Chief cells
   - secrete pro-enzymes (pepsinogen)
3. Enteroendocrine cells
   - produce hormones such as gastrin
   - produce histamine
4. Mucous secreting cells

Question 3

What are the specialised features of the small intestine regions?

Answer 3

1. Duodenum
   - Brunners glands (secrete alkaline mucous)
2. Jejenum
   - No brunners
   - No Peyers patches
   - Less fat, thick wall, lots of folds
   - Long vasa recta
3. Iluem
   - Peyers patches
   - More fat