Search results
Results From The WOW.Com Content Network
The organs of Bojanus or Bojanus organs are excretory glands that serve the function of kidneys in some of the molluscs. In other words, these are metanephridia that are found in some molluscs, for example in the bivalves. Some other molluscs have another type of organ for excretion called Keber's organ.
(In mollusca, it is known as the Bojanus organ.) A metanephridium typically consists of the nephrostome (a ciliated funnel) opening into the body cavity , connected to a duct which may be variously glandularized, folded or expanded (vesiculate) and which typically opens to the organism 's exterior.
De-oxygenated haemolymph drains into a large venous sinus within the head and foot, which contains the nephridium, an excretory organ with a function similar to that of the vertebrate kidney. From here it passes into vessels within the gill, or into the capillary network of the pulmonate lung, before returning to the heart.
In some mollusks the mantle cavity is a brood chamber, and in cephalopods and some bivalves such as scallops, it is a locomotory organ. The mantle is highly muscular. In cephalopods the contraction of the mantle is used to force water through a tubular siphon, the hyponome , and this propels the animal very rapidly through the water.
A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda (members of these classes include saltwater and freshwater snails, clams, octopus, squid and relatives). Siphons in molluscs are tube-like structures in which water (or, more rarely, air) flows.
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks [a] (/ ˈ m ɒ l ə s k s /). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda . [ 5 ]
It is located between the bladder and the labrum. Inside it is a large blood-facuna. It has two levels in the wall. Its walls have numerous blood vessels which are the outer layer, the inner layer is thin and contains large excretory epithelial cells. The end sac functions similarly to the vertebrate glomerular nephron.
The reniculate kidney is a multilobed kidney found in marine and aquatic mammals such as pinnipeds (seals, sea lions and walruses) and cetaceans (dolphins and whales) but absent in terrestrial mammals except bears. [1] Kidneys of this morphology have increased surface area for removing toxins from the body more efficiently than a non-lobed kidney.