Kidneys and Kidney Functions

Essential function of removing waste products from the blood and regulating the water fluid levels. The diagram below shows the basic structure of the kidney.

 

 The kidneys receive blood through the renal artery. The blood is passed through the structure of the kidneys called nephrons, where waste products and excess water pass out of the blood stream, as shown in the diagram below. 

 

When the venom induces clotting, the fibrin is deposited in the tubules. As the tubules are blocked, the kidneys are not able to remove the same amount of waste products from the blood, and urea and cretinine begin to accumulate in the blood. If these chemicals are not removed, the concentrations become lethal.

When the kidneys are not functional, dialysis becomes necessary to save the victim. In dialysis, the blood passes through an external membrane which allows waste products from the blood to pass out of the blood and into the dialysis fluid. Because of the rate of buildup of the waste products, it may be necessary to perform dialysis as many as 3 times per week.

What do the kidneys do?

 

The kidneys regulate the body's fluid volume, mineral composition and acidity. They do this by regulating excretion and reabsorption of water and inorganic electrolytes. This works to balance these substances throughout the body and keep their normal concentrations in the extracellular fluid. Ions regulated in this way include sodium, potassium, chloride, calcium, magnesium, sulfate, phosphate and hydrogen. The kidneys regulate body fluid volumes, which are related to blood volume and the blood pressure in your arteries. The kidneys also regulate some organic nutrients and excrete metabolic waste products and some foreign chemicals.

 

How does the kidney help regulate blood pressure?

 

Regulating blood pressure is intimately linked to the kidneys' ability to excrete enough sodium chloride to maintain normal sodium balance, extracellular fluid volume and blood volume. Kidney disease is the most common cause of secondary hypertension (high blood pressure). Even subtle disruptions in kidney function play a role in most (if not all) cases of high blood pressure and increased injury to the kidneys. This injury can eventually cause malignant hypertension, stroke or even death.

 

In normal people, when there's a higher intake of sodium chloride (salt), the body adjusts. It excretes more sodium without raising arterial pressure. However, many outside influences and kidney problems can lead to reduced capability to excrete sodium. If the kidneys are less able to excrete salt with normal or higher salt intake, chronic increases in extracellular fluid volume and blood volume result. This leads to high blood pressure. When higher levels of hormones and neurotransmitters that directly cause blood vessels to narrow are also present, even small increases in blood volume are compounded. (This is due to the smaller area through which the blood is forced to flow.) Although the increases in arterial pressure lead the kidneys to excrete more sodium, which restores the sodium balance, higher pressure in the arteries may persist. This shows the important link between kidney disease and high blood pressure.