The part from the stomata to the gizzard is called the anterior alimentary canal. It consists of six parts. These are:
(i) Mukhashidra: The openings in front of the alimentary canal are called mukhashidras. Food enters through it
(ii) Oral cavity: The part enclosed by the oral cavity after the oral cavity is called oral cavity. Food is mixed with saliva in the mouth. It takes the food from the mouth to the pharynx.
(iii) Pharynx: The small, muscular, narrow and cylindrical part located behind the mouth is called pharynx. Through this, food enters the esophagus.
(iv) Esophagus: The narrow, long and cylindrical part after pharynx is called esophagus. It is covered by a thin wall. It transports the food to the crop.
(v) Croup: Esophagus swells to form a sac-like croup. It is thin walled. Food is temporarily stored in it. Food digestion starts from here. Dr. Siddiq Publications
(vi) Gizzard or proventriculus: The posterior extension of the crop is called gizzard. It is a thick, muscular and triangular sac. Its wall is made up of tough, thick and circular muscles. The anterior part of the gizzard is called the armarium and the posterior part is the stomodium captica. Armarium wall folded longitudinally to form six leaf-like teeth. There is a pad-like layer behind the teeth. These leaves have fine bristles or hairs. Longitudinal folds contain bristles in deep pits. Gizzard teeth crush food. Bristle or Rome serves as strainer. Kapatika prevents reverse flow of food.