Excretory System

The system that excretes waste from the body.

Sponge

Water flow through the sponges orifice and pores caries out the waste.

Any mineral particles, that enter the sponge through the water flow system, that threaten to block the sponge, are transported through the mesohyl (a gelaatious matrix within the sponge) and are generally dumped into the outgoing water current.

Earth Worm

The excretory system of an earthworm is said to be extremely simple. The food that the earthworm eats simply goes in one end of the worm, and comes out the other. Similar to human kidneys, Niphridia, which all invertebrates use as their excretory organ, are found in all but 4 segments. This being the first three, and the last one, which are known as Musurca. Before the food is execrated the food moves through the gizzard where the soil is ground up with little stones, releasing organic matter. Some water is reabsorbed by the blood, although the remainder is excreted through the Nephridia, or to be more specific, Metanephridia (the type of Nephrida).

Frog

The organs in the frogs execratory system are the: Kidneys Ureters Bladder Cloaca

Along with all of these organs, frogs also exchange substances just like mammals through their skin. An example of this would be water.

The Frogs excretory system starts by liquid wastes traveling from the kidneys to the ureters then to the urinary bladder. The solid wastes however pass into the cloaca from the large intestine. Both of these waste materials leave the body through the cloaca and the cloacal vent.

Human

Wastes that are removed in the human excretory system are; carbon dioxide, water, urea, and uric acid. All these wastes that are excreted travel through the blood stream at some time.

Organs of the human Excretory System and their function are: Lungs – remove excess carbon dioxide. Liver – produces urea and uric acid as a by-product of the

breakdown of proteins. Skin – Removes excess water, salt, urea, and uric acid

through sweating. Aorta – Starts on the left side of the heart and sends blood to

main parts of the body. Including the kidneys. Urinary System (bladder, kidneys, ureters) – The kidneys filter

the blood to form urine containing excess water, salt, urea, and uric acid.

Sources:

http://qldscienceteachers.tripod.com/junior/biology/excretory.html

http://answers.yahoo.com/question/index?qid=20090401225022AAEDvYJ

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20102/bio%20102%20lectures/animal%20diversity/lower%20invertebrates/sponges.htm

http://www.lookd.com/frogs/anatomy.html http://www.scienceray.com/Biology/Human-Biology/Human-

Body-The-Excretory-System.116217 http://www.angelfire.com/de2/atoy/dex.htm http://www.emc.maricopa.edu/faculty/farabee/BIOBK/

BioBookEXCRET.html