Changes

[[Image:Cockatiel.jpg|thumb|right|200px|Cockatiel - Copyright nabrown 2008]]

[[Image:Cockatiel.jpg|thumb|right|200px|Cockatiel - Copyright nabrown 2008]]

The [[Avian Digestive Tract - Anatomy & Physiology|avian alimentary system]] differs immensely from the basic mammalian design. Food can move in a  retrograde fashion from the [[The Proventriculus - Anatomy & Physiology|proventriculus]] to the [[Crop- Anatomy and Physiology|crop]]. Food can also pass from the [[The Gizzard - Anamtomy & Physiology|gizzard]] back into the [[The Proventriculus - Anatomy & Physiology|proventriculus]] depending on particle size, which is similar to that in mammals. The egestion of bones occurs once the nutritious material has been ingested. During reflux, gastric motility is inhibited and the pellet is expelled through the [[The Avian Oral Cavity - Anatomy & Physiology|oral cavity]] by oesophageal antiperistaltis. This cleans the [[Crop- Anatomy and Physiology|crop]] out and checking the pellet of captive birds should be undertaken daily to assess health.

The [[Avian Digestive Tract - Anatomy & Physiology|avian alimentary system]] differs immensely from the basic mammalian design. Food can move in a  retrograde fashion from the [[The Proventriculus - Anatomy & Physiology|proventriculus]] to the [[Crop- Anatomy and Physiology|crop]]. Food can also pass from the [[The Gizzard - Anamtomy & Physiology|gizzard]], which is the equivalent of a muscular stomach back into the [[The Proventriculus - Anatomy & Physiology|proventriculus]] depending on particle size. The egestion of bones occurs once the nutritious material has been ingested. During reflux, gastric motility is inhibited and the pellet is expelled through the [[The Avian Oral Cavity - Anatomy & Physiology|oral cavity]] by oesophageal antiperistaltis. This cleans the [[Crop- Anatomy and Physiology|crop]] out and checking the pellet of captive birds should be undertaken daily to assess health.

The avian [[The Avian Intestines - Anatomy & Physiology|intestines]] shows some species specific anatomical variety, and the hindgut of the avian digestive system differs from mammalian anatomy as it terminates in the [[The Avian Vent and Cloaca - Anatomy & Physiology|cloaca]]. The external opening through which faecal matter and uric acid is excreted is called the [[The Avian Vent and Cloaca - Anatomy & Physiology|vent]]. The shape of the vent varies depending on species. Avian species vary in the presence or absence of a [[Avian_Liver_-_Anatomy_%26_Physiology#Gallbladder:_Species_Differences|gall bladder]], and the avian [[Avian Liver - Anatomy & Physiology|liver]] differs from the mammalian liver, being bilobular.

The avian [[The Avian Intestines - Anatomy & Physiology|intestines]] shows some species specific anatomical variety, and the hindgut of the avian digestive system differs from mammalian anatomy as it terminates in the [[The Avian Vent and Cloaca - Anatomy & Physiology|cloaca]]. The external opening through which faecal matter and uric acid is excreted is called the [[The Avian Vent and Cloaca - Anatomy & Physiology|vent]]. The shape of the vent varies depending on species. Avian species vary in the presence or absence of a [[Avian_Liver_-_Anatomy_%26_Physiology#Gallbladder:_Species_Differences|gall bladder]], and the avian [[Avian Liver - Anatomy & Physiology|liver]] differs from the mammalian liver, being bilobular.