• The overall histological morphology of the GIT consists of 4 main layers:

Mucosa

epithelial lining

lamina propria (connective tissue)

muscularis mucosa - thin layer of smooth muscle

Submucosa

connective tissue

blood and lymph vessels

submucosal plexus

Muscularis externa

inner layer of circular smooth muscle

outer layer of longitudinal smooth muscle

myenteric plexus

Serosa

secretes watery fluid to lubricate organs

is continuous with the mesentery which carries the blood vessels, lymphatics and nerves to and from the tract