Structural Organization In Animals

Calcium carbonate

Ammonia

Potassium urate

Urea

Pharynx $\to$ Oesophagus $\to$ Crop $\to$ Gizzard $\to$ Ileum $\to$ Colon $\to$ Rectum

Pharynx $\to$ Oesophagus $\to$ Gizzard $\to$ Crop $\to$ Ileum $\to$ Colon $\to$ Rectum

Pharynx $\to$ Oesophagus $\to$ Gizzard $\to$ Ileum $\to$ Crop $\to$ Colon $\to$ Rectum

Pharynx $\to$ Oesophagus $\to$ Ileum $\to$ Crop $\to$ Gizzard $\to$ Colon $\to$ Rectum