Changes

==Gastrointestinal Tract==

==Gastrointestinal Tract==

The organs and divisions of the gastrointestinal tract are similar to those of mammals. The lizard has a simple, elongated stomach. The liver may contain melanin and have black spots - all lizards have a gall bladder. A caecum is present in many species and herbivorous lizards have a sacculated colon to aid fermentation.

The organs and divisions of the gastrointestinal tract are similar to those of mammals. The lizard has a simple, J-shaped, elongated stomach. A caecum is present in many species. The large intestine is thin-walled and less muscular than the stomach or small intestines.

 

Herbivorous lizards such as the green iguana, prehensile-tailed skink, egyptian spiny-tailed lizard and chuckwalla (''Sauromalus obesus'') have a sacculated colon to facilitate hindgut fermentation. These animals usually have higher optimal body temperature zones in order to enhance microbial fermentation.

==Cloaca==

==Cloaca==

A cloaca is present and is divided into coprodeum (collects faeces), ureodeum (collects urinary wastage) and proctodeum (final chamber prior to elimination)

A cloaca is present (with a transverse cloacal slit) and is divided into three parts:

* coprodeum (collects faeces)

* ureodeum (collects urinary wastage)

* proctodeum (final chamber prior to elimination)