Answer briefly:
What are the basic layers of the wall of alimentary canal?

(N/A) The walls of the alimentary canal are made up of four layers. These are as follows:
$(i)$ Serosa is the outermost layer of the human alimentary canal. It is made up of a thin layer of secretory epithelial cells,with some connective tissues underneath.
$(ii)$ Muscularis is a thin layer of smooth muscles arranged into an outer longitudinal layer and an inner circular layer.
$(iii)$ Sub-mucosa is a layer of loose connective tissues,containing nerves,blood,and lymph vessels. It supports the mucosa.
$(iv)$ Mucosa is the innermost lining of the lumen of the alimentary canal. It is mainly involved in absorption and secretion.