GENERAL HISTOLOGY

Detailed explanation-1: -The kidneys, in mammals, are a pair of bean-shaped structures that are located just below and posterior to the liver in the peritoneal cavity. The adrenal glands sit on top of each kidney and are also called the suprarenal glands. Kidneys filter blood and purify it.

Detailed explanation-2: -Evolutionary anthropologists guess that we have two limbs, two lungs and two kidneys because these dual organs gave our ancestral organisms some kind of advantage, not because they’re spare parts We can see with one eye (and one-eyed organisms evolved first), but two eyes offer the advantage of depth perception.

Detailed explanation-3: -And some animals still only have one kidney. Around 500 million years ago, our long-lost relatives that were living in the ocean (some of whom probably only had one kidney) decided to leave the water to walk and live on land.

Detailed explanation-4: -There are two kidneys, each about the size of a fist, located on either side of the spine at the lowest level of the rib cage. Each kidney contains up to a million functioning units called nephrons.

Detailed explanation-5: -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.