What are the primary structures and functions of the human excretory system?

Answer 1

You have two bean shaped stuctures placed in postrior abdominal wall. They are retroperitoneal. Right kidney is slightly lower than left due to liver on right side. It is 3*2*1 inches in dimentions. On cross section you can see the cortex and medula. You have minor and major calices. Microscopically, you have one million of nephrons in each kidney. There you have glomerulus, descending and ascending loops of henley and collecting ducts. From cortex to medula, you have higher concentration of salt. for this lot of energy is spent. Brain is the organ, which is most vulnerable to excess of toxic products of metabolism. That is serum urea. To excreate urea, kidney filters out 180 liters of fluid each day and more than 178 liters are reabsorbed. That is the main function of kidney. It also regulates the water balance of body. It maintains the pH balance of body. It maintains the salt balance of the body as well. It has endocrines functions as well. By secreating 'Renin' hormone, it activates the renin angiotensin aldesteron mechanism to increase the blood pressure if challenged. It also secretes hormone erythropoitin to stimulate the production of red blood cells. It also converts the 25 hydroxy cholecalciferol to 1,25 cholecalciferol or calcitriol.

Answer 2

The Excretory system is responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process, such as sweat glands, the liver, the lungs and the kidney system. Every human has two kidneys.