Q. What are the special structures of the avian digestive tube and their respective functions?
The crop has the function of temporary storage of ingested food and it is a more dilated area of the avian esophagus, the digestive tube of birds has special structures in this sequential order the crop the gizzard and the proventriculus, the proventriculus is the chemical stomach of the birds where food is mixed with digestive enzymes, the gizzard is a muscular pouch that serves as a mechanical stomach where the food is ground to increase the exposure area of the food particles for the digestive enzymes to act.