Search results
Results from the WOW.Com Content Network
The kidneys are seen as two elongated, red organs in this image. The opisthonephros is the functional adult kidney in lampreys (cyclostomes), most fishes, and amphibians. [1] It is formed from the extended mesonephros along with tubules from the posterior nephric ridge. [2] The functional embryonic kidney in anamniotes is the pronephros.
The amphibian bladder is usually highly distensible; among some land-dwelling species of frogs and salamanders, it may account for 20%–50% of total body weight. [44] Urine flows from the kidneys through the ureters into the bladder and is periodically released from the bladder to the cloaca. [45]
Frogs have no tail, except as larvae, and most have long hind legs, elongated ankle bones, webbed toes, no claws, large eyes, and a smooth or warty skin. They have short vertebral columns, with no more than 10 free vertebrae and fused tailbones (urostyle or coccyx). [ 47 ]
These amazing frogs can survive these conditions because their body produces a kind of natural anti-freeze. It is a combination of glucose (produced by the liver) and the chemicals found in urine.
Bladder stones may occur whenever the kidneys, bladder, or ureters become inflamed, which may occur when the urine becomes too concentrated or when the body becomes dehydrated. Minerals such as calcium and magnesium crystallize into the stones, which then can cause such symptoms as lower back or abdominal pain or difficulty with urination.
secretion – the remaining fluid becomes urine, which travels down collecting ducts to the medullary region of the kidney. excretion – the urine (in mammals) is stored in the urinary bladder and exits via the urethra; in other vertebrates, the urine mixes with other wastes in the cloaca before leaving the body (frogs also have a urinary ...
Paleontologists have discovered a previously unknown ancient species: Kermitops — an amphibian that predates the dinosaurs and reveals the complexity of frog evolution. Researchers found a tiny ...
The shape of the kidneys varies between reptiles due to variations of their body form. [8] The kidneys of snakes are elongated, cylindrical [53] [50] and lobulated. [52] Turtles and some lizards have urinary bladder [50] that opens into the cloaca [54] but snakes and crocodiles do not have it. [50]