When Patton Oswalt lets loose on Twitter (letâs skip the loaded troll descriptor for now), he really digs in and this time he exposed previously unknown depths of reaching when he somehow elicited Breitbart editor Ben Shapiro to inexplicably whine about anti-semitism and generally lose his mind.
Digestive System. Echinoderms have a simple digestive system with a mouth, stomachs, intestineand anus. In many, the mouth is on the underside and the anus on the top surface of the animal. Sea stars can push their stomachs outside of their body and insert it into its prey allowint them to digest the food externally.
It is one (1) of four (4) organ systems that are responsible for excretion. Excretion is simply a process by which the body gets rid of waste materials, such as urine, faeces, excess water and carbon dioxide. The other three organ systems responsible for excretion are the respiratory system, the digestive system and the integumentary system.