The gizzard has a thin, but tough '''mucous membrane'''. It has a pale, thin lining raised into ridges with three layers of '''lamina muscularis'''. The gizzard also has cuboidal epithelium and some tubular glands present. There is a thick keratin layer to protect the muscle. | The gizzard has a thin, but tough '''mucous membrane'''. It has a pale, thin lining raised into ridges with three layers of '''lamina muscularis'''. The gizzard also has cuboidal epithelium and some tubular glands present. There is a thick keratin layer to protect the muscle. |