10 terms

Layers of Alimentary Canal Wall (21.4)

The Digestive System
The alimentary canal is composed of how many layers?
The deepest layer of the alimentary canal is:
mucosa, or mucous membrane
The second deepest layer is:
The second superficial layer is:
muscular layer
The most superficial layer is:
serous layer
The layers of the alimentary canal from deepest to superficial:
mucosa, submucosa, muscular layer, serous layer
Mucosa (mucous membrane) layer:
formed by epithelium and some connective tissue, comes into direct contact with food passing through the canal. It secretes mucus that protects and lubricates the lining
Submucosa layer:
composed of loose connective tissue, blood vessels, and many nerve endings. The blood vessels carry away the nutrients that are absorbed, and the nerve endings stimulate the muscle fibers so that the food is continually moving by peristalsis
Muscular layer:
consists of a circular band and a longitudinal band of visceral muscles; is the thickest of the four layers. Main function: peristalsis
Serous layer:
it is continuous with the mesentery, the connective tissues that attach to the posterior body wall and hold the digestive organs in their proper position