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Carnivorous Plants - Plants That Eat Form and Function in Birds, edited by A. The human chest is separated from the abdomen by a powerful muscular partition, the diaphragm see Diaphragm. Their digestive system consists of a pancreas along with a liver and gall bladder. Most of these species lay eggs in water with the larva being aquatic. The "tail" is only possessed by the male and is an extension of the cloaca and used to inseminate the female. Members of the three extant orders differ markedly in their structural appearance.
Evolution of Amphibians
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Skip to secondary content. Take this fun science quiz for kids about the Human Excretory System! This fun interactive quiz is all about the human excretory system! Let's see how well you know about the basics of the human excretory system and its functions.
Click here to learn about Human Excretory System Basics What happens to the blood after it passes through the kidneys? When we breathe When we poop When we sweat When we vomit. The blood is cleaned The poop is stored The food is digested The blood if pumped. It is a machine that helps process the waste if there is a kidney malfunction It is a machine used to clean the intestine It is a method of eliminating poop It is a method of eliminating gaseous waste. Yes, water helps our heart work well No, we can drink any liquid Yes, water helps our body organs function well and replenishes our lost liquids No, we only need to drink water once a month.
Spit Feces Mucous Urine. A person's heart stops A person becomes very tired A person will have his leg removed A person can get sick because toxins and waste are not removed from the body.
Lung Rectum Bladder Kidney. Eventually, the tubules usually lose their internal openings to the body cavity. The most anterior tubules of the archinephros pronephros usually degenerate in the adult. These ducts and tubules also subserve the reproductive function, and for this reason they are also called the urogenital system. The extent to which the ducts and tubules are shared is greater in the male than in the female. In the male the spermatic tubules of the testis connect with the kidney tubules in the middle region of the archinephros mesonephros , and in some vertebrates e.
In the reptiles, birds, and mammals there is greater separation of function, the mesonephros being exclusively genital and the metanephros being exclusively urinary. In the female, even in the lower vertebrates, the two systems are confluent only at the posterior end. It has been held that the oviduct is a derivative of the archinephric duct, but the evidence for this is not compelling.
In primitive marine animals the blood is almost identical with seawater in composition; in typical freshwater animals the concentration of the blood is about half that of seawater. The earliest fossil vertebrates are found in marine deposits, but the fossil record shows clearly that the early evolution of fishes took place in fresh water.
It is assumed that the blood of early freshwater fishes, like that of other freshwater animals, was osmotically equivalent to half-strength seawater. The sharks and rays returned to the sea during the Carboniferous Period , and no doubt at that time they evolved the device of urea retention. The bony fishes returned to the sea later, in the Mesozoic Era , and solved their problem by swallowing seawater and rejecting excess salt at the gills.
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Our editors will review what you've submitted, and if it meets our criteria, we'll add it to the article. Please note that our editors may make some formatting changes or correct spelling or grammatical errors, and may also contact you if any clarifications are needed. Evolution of the vertebrate excretory system Studies of the embryonic development of primitive vertebrates, such as the dogfish shark, clearly show that the excretory system arises from a series of tubules, one pair in every segment of the body between the heart and the tail.
Page 11 of Learn More in these related Britannica articles: The biosphere is a global ecosystem composed of living organisms biota and the abiotic nonliving factors from which they derive energy and nutrients.
An organism can minimize the potential damage of absorbed toxins by excreting the chemical or by changing the chemical into a different chemical biotransformation , or by both methods. The body can excrete exogenous chemicals in the urine, bile, sweat, or milk; the lungs can…. The blood carries the waste products of cellular metabolism to the excretory organs. The removal of carbon dioxide via the lungs has been described above. Water produced by the oxidation of foods or available from other sources in excess of needs is excreted by….
The main route of drug excretion is through the kidneys; however, volatile and gaseous agents are excreted by the lungs. Small quantities of drugs may pass into sweat, saliva, and breast milk, the latter being potentially important in breast-feeding mothers.