Role Of The Kidneys In The Regulation Of Intra
Seriki A Samue1*, Adebayo O Francis1 and Odetola O Anthony2
1Department of Human Physiology, College of Medicine, Bingham University, Karu, Nigeria2Department of Human Physiology, Faculty of Medicine, Nnamdi Azikiwe University, Awka, Nigeria
*Address for Correspondence: Seriki A. Samuel, Department of Human Physiology, College of Medicine, Bingham University, Karu, Nigeria, Tel: +2348036041121 Email: [email protected]
Dates:Submitted: 05 July 2018 Approved: 16 July 2018 17 July 2018
How to cite this article: Samuel SA, Francis AO, Anthony OO. Role of the Kidneys in the Regulation of Intra- and Extra-Renal Blood Pressure. Ann Clin Hypertens. 2018 2: 048-058. DOI: 10.29328/journal.ach.1001011
Copyright:© 2018 Samuel SA, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Keywords: Hypertension Renin Angiotensin System Natriuresis Sodium balance homeostasis
Secretion Of Active Compounds
The kidneys release a number of important compounds, including:
- Erythropoietin: This controls erythropoiesis, or the production of red blood cells. The liver also produces erythropoietin, but the kidneys are its main producers in adults.
- Renin: This helps manage the expansion of arteries and the volume of blood plasma, lymph, and interstitial fluid. Lymph is a fluid that contains white blood cells, which support immune activity, and interstitial fluid is the main component of extracellular fluid.
- Calcitriol: This is the hormonally active metabolite of vitamin D. It increases both the amount of calcium that the intestines can absorb and the reabsorption of phosphate in the kidney.
Function Of The Kidney
The primary function of the kidney is to continuously remove nitrogenous wastes from the body. This, however, is not its only function. It performs a number of other crucial functions, making it one of the most versatile organs of the body.
In this article, we outline eight key functions performed by the kidneys.
1. Primary Function: Removing Wastes Products from the Blood
Filtering blood is the primary function of the kidney. This process is handled by the urinary excretory system, of which the kidneys are the main organs. Every day the kidneys process about 200 quarts of blood and filters out about 2 quarts of waste products and extra water.
Waste is any substance that is not useful to the body. This could be any substance or chemical that the body cannot use at all, or even if the body can use it, if it is present in excess of what the body needs then the excess is classified as waste. If wastes are allowed to accumulate in the body, the results can be deadly. It is, therefore, crucial for wastes to be eliminated from the body, relatively quickly.
2. Urine Formation – Another Vital Function of the Kidney
Once the kidneys have filtered the blood and removed the waste products from it, the next step is to get rid of the wastes from the body. Urine formation is the process by which the kidneys prepare waste products, filtered from the blood, for elimination from the body.
3. Regulating the body’s water volume
4. The Kidneys Regulate The Body’s Salt Content
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Bowmans Capsule To Proximal Tubule
The first part of the nephron is the Bowmans capsule into which a group of blood capillaries sits. These blood vessels are called a glomerulus. Some substances in the blood are able to pass through the thin walls of the glomerulus and enter the capsule.
These substances then also filter through the special thin-walled cells of the Bowmans capsule where they pass into the first tubule, the proximal convoluted tubule of the nephron. Sugars, ions, and water are filtered through cells of the capsule that are known as podocytes.
The proximal convoluted tubule is where a lot of the glucose is reabsorbed and returned to the bloodstream. In addition, some ions of sodium along with amino acids are transported out of the tubule.
Some urea and uric acid, both metabolic wastes, are also secreted into the filtrate in the tubule at this stage. A certain amount of water is also reabsorbed here.
Hypertension And Kidney Health
Hypertension which is another name for high blood pressure is the No. 2 cause of chronic kidney disease in the United States. In fact, 80 percent to 85 percent of people with chronic kidney disease have hypertension.
Chronic kidney disease can cause hypertension likewise, hypertension can cause chronic kidney disease. Regardless of which came first, its vital to have blood pressure well-controlled and to take medications that help off-load pressure on the kidney.
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What Else Do Kidneys Do
Kidneys are always busy. Besides filtering the blood and balancing fluids every second during the day, the kidneys constantly react to hormones that the brain sends them. Kidneys even make some of their own hormones. For example, the kidneys produce a hormone that tells the body to make red blood cells.
Now you know what the kidneys do and how important they are. Maybe next Valentine’s Day, instead of the same old heart, you can give your parents a special card featuring the kidneys!
Microscopic Anatomy Of Kidney
Nephrons are the structural and functional unit of renal system. Each human adult kidney contains around 1 million nephrons. The microscopic structure of kidney consist of two main parts: Nephrons and Collecting ducts. Nephron is divided into two parts renal corpuscles and tubules (Proximal convoluted tubules, Loop of Henle and Distal convoluted tubules.
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Top 5 Jobs Kidneys Do
In a popular 1970 song, singer-songwriter Joni Mitchell asked, Dont it always seem to go that you dont know what youve got till its gonea question that could have been aimed at people with kidney disease. The kidneys play a crucial role in maintaining overall health, but are rarely appreciated until they become damaged and can no longer do their jobs.
Do you know what your kidneys do every day to keep you healthy? The answer is quite a lot. The kidneys play an important role in keeping your body functioning properly. Here are the 5 top jobs healthy kidneys perform.
1. Remove wastes and extra fluid
Your kidneys act like a filter to remove wastes and extra fluid from your body. Your kidneys filter about 200 quarts of blood each day to make about 1 to 2 quarts of urine. The urine contains wastes and extra fluid. This prevents buildup of wastes and fluid to keep your body healthy.
2. Control blood pressure
Your kidneys need pressure to work properly. Kidneys can ask for higher pressure if it seems too low, or try to lower pressure if it seems too high by controlling fluid levels and making the hormone that causes blood vessels to constrict.
3. Make red blood cells
Your kidneys make a hormone called erythropoietin. Erythropoietin tells bone marrow to make red blood cells. Red blood cells carry oxygen from your lungs to supply all your body’s needs. Red blood cells give you the energy you need for daily activities.
4. Keep bones healthy
5. Control pH Levels
The 7 Functions Of The Kidneys
Most people know that the primary function of the kidneys is to eliminate waste products from the body by flushing them out with urine. However, did you know that there are at least 6 other fabulous functions you should thank your kidneys for?
Shaheen Motiwala, MD is one of our nephrologist at Florida Kidney Physicians who loves to educate patients. Here is a brief overview of the 7 primary functions of the kidneys to help patients become more familiar with how these amazing organs work.
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How Does Blood Flow Through My Kidneys
Blood flows into your kidney through the renalartery. This large blood vessel branches into smaller and smaller blood vessels until the blood reaches the nephrons. In the nephron, your blood is filtered by the tiny blood vessels of the glomeruli and then flows out of your kidney through the renal vein.
Your blood circulates through your kidneys many times a day. In a single day, your kidneys filter about 150 quarts of blood. Most of the water and other substances that filter through your glomeruli are returned to your blood by the tubules. Only 1 to 2 quarts become urine.
What Are The 3 Main Functions Of The Kidneys
The kidneys perform many crucial functions, including:
- maintaining overall fluid balance.
- regulating and filtering minerals from blood.
- filtering waste materials from food, medications, and toxic substances.
- creating hormones that help produce red blood cells, promote bone health, and regulate blood pressure.
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Which Of The Following Is Not A Function Of The Kidneys
B.Regulating urine volume and composition.
C.Regulation of water, electrolyte, and pH balance.
D.Long-term control over blood pressure.
E.None of the above.
The correct answer is B. Regulating urine volume and composition.
The excretory organ of vertebrate animals is the kidney. This organ is crucial for survival and has many important functions in the human body.
It is not only how we rid the body of metabolic waste products but also helps us to control the water balance of the body. Blood pressure, electrolyte levels and the pH of the body are all carefully regulated by the action of the kidney.
In humans, we have two kidneys, one on either side of the body. Each of these kidneys contains millions of microscopic structures known as nephrons.
Each nephron is surrounded by blood capillaries and consists of a capsule and several tubules. The first region is the Bowmans capsule which has a clump of blood capillaries that sit inside it.
This capsule then leads into the proximal convoluted tubule. Much of the glucose is reabsorbed here and some urea is secreted into the filtrate.
Salt is reclaimed along with water in the region known as the loop of Henle. The next part of the nephron is the distal convoluted tubule which is also where pH is regulated by the secretion or absorption of protons or bicarbonate ions.
What Do Kidneys Do
One of the main jobs of the kidneys is to filter the waste out of the blood. How does the waste get in your blood? Well, your blood delivers nutrients to your body. Chemical reactions in the cells of your body break down the nutrients. Some of the waste is the result of these chemical reactions. Some is just stuff your body doesn’t need because it already has enough. The waste has to go somewhere this is where the kidneys come in.
First, blood is carried into the kidneys by the renal artery . The average person has 1 to 1½ gallons of blood circulating through his or her body. The kidneys filter that blood about 40 times a day! More than 1 million tiny filters inside the kidneys remove the waste. These filters, called nephrons , are so small you can see them only with a high-powered microscope.
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How Do Kidneys Work:
As blood flows through the body it picks up waste and carries this to the kidneys using the kidney arteries. The waste in your blood comes from the normal breakdown of active tissues and from the food you eat. Your body uses food for energy and selfrepair. After the body has taken what it needs, from the food, the waste is sent to the blood. The kidneys filter out the waste products and excess fluids from the body and dispose of them in the form of urine, via the bladder. The clean blood flows back to the other parts of the body. If your kidneys did not remove this waste, it would build up in the blood and cause damage to your body.
The actual filtering occurs in tiny units inside your kidneys called nephrons. Each kidney contains about a million nephrons. In the nephron, a glomerulus intertwines with a urine collecting tube called tubules. A complicated chemical exchange takes place, as waste materials and water in your blood enter your urinary system.
In addition to removing waste, the kidneys have other important functions. These are carried outwith the help of three hormones, which are released in the kidneys.
What Matters Most To You
Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.
Reasons to choose hemodialysis at a dialysis centre
Reasons to choose peritoneal dialysis
I feel more comfortable having professionals handle the procedure.
I am confident that I can do the procedure myself.
I don’t want to have dialysis every day.
I don’t mind having dialysis every day.
I live near a dialysis centre or am able to get to a dialysis centre.
I live far from a dialysis centre or have trouble getting around.
I prefer to be around others who are also getting dialysis.
I like the independence of doing the dialysis myself.
I don’t mind people sticking needles in me.
I hate having needles stuck in me.
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What Is The Function Of Our Kidneys
The kidneys are a very important organ in the body. They are two bean-shaped organs, each about the size of a fist, located just below the rib cage, one on each side of your spine. The kidneys are responsible for getting rid of waste products, drugs, and toxins through our urine.
Your kidneys also:
- Regulate amount of fluid within the body
- Help regulate blood pressure
- Produce hormones that affect blood and bones
- A kidney is composed of tiny units called nephrons
- Nephrons consist of glomeruli and tubules
- Glomeruli are small blood vessels that filter wastes and excess fluids
- Tubules collect the waste to form urine
What Are The Types Of Dialysis
Dialysis is a process that does the work of healthy kidneys when you have kidney failure. Dialysis filters wastes, removes extra fluid, and restores the proper balance of chemicals in the blood.
There are two basic types of dialysis: hemodialysis and peritoneal dialysis.
- Hemodialysis uses a man-made membrane called a dialyse to clean your blood. You are connected to the dialyse by tubes attached to your blood vessels. Before hemodialysis treatments can begin, your doctor will need to create a site where blood can flow in and out of your body. This is called the dialysis access. In some cases, hemodialysis can be done at home. You will need to be trained, and you will need to make room for the dialysis machine. You may have choices for how often and how long you need dialysis.
- Peritoneal dialysis uses the lining of your belly, which is called the peritoneal membrane, to filter your blood. Before you can begin peritoneal dialysis, your doctor will need to place a catheter in your belly for the dialysis access.
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The Urinary System Is One Of The Bodys Systems Which Helps Us To Dispose Of The Waste Products Naturally Produced Within The Body The Main Structures In This System Are:
- Two kidneys which lie behind the other major organs in the lower back area. They are bean-shaped organs and measure about 11cm long, 6cm wide and 3cm deep. They have 5 main functions, which will be discussed at a later stage.
- Two ureters which run from the kidneys to the bladder carrying urine.
- One bladder which collects urine from the kidneys, via the ureters, and stores it temporarily.
- One urethra through which the urine is excreted out of the body, allowing the bladder to empty and dispose of the waste.
The Collecting Duct Blood Pressure And Electrolyte Regulation
In the collecting duct, additional water is reclaimed from the fluid and other substances are secreted into the tubule. This duct is where substances can be reabsorbed and secreted so as to ensure electrolytes are in the correct balance.
Cells in this area respond to antidiuretic hormone and the hormone aldosterone. Sodium is taken up and potassium secreted by means of sodium-potassium pumps in the membrane of the duct.
These pumps are influenced by the concentration of aldosterone in the blood, with more sodium taken up if there is more of the hormone present.
The reabsorption of salt then leads to reabsorption of water along an osmotic gradient. It is important to remember that increased solute means decreased water molecules.
Thus, if there is more salt outside of a tubule than inside, water will tend to move out of the tubule into the surrounding cells where the salt concentration is high.
This then helps to increase your blood pressure if needed since more water can be reclaimed and returned to the blood circulation. The result of this is that your blood pressure can be regulated over the long term by the action of the kidney responding to hormones.
Increased levels of antidiuretic hormone lead to increased water reabsorption. This is important in ensuring that we do not lose too much water, especially when we are dehydrated.
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Keeping Your Kidneys Healthy
Well-functioning kidneys are essential to your overall health. Early detection of kidney disease can be life-saving. Medication and changes to lifestyle, along with an early referral to a kidney specialist, can prevent or delay kidney failure.
If you are at increased risk of chronic kidney disease, talk to your doctor about having a regular kidney health check.
Nerve Supply Of Kidney
- Kidney and nervous system communicates via renal plexus .
- Renal nerve arise from superior mesenteric ganglion and enter the hilum of each kidney and follow branches of renal artery to reach individual nephrons.
- These nerves consist mostly of sympathetic fibers that trigger vasoconstriction in kidney.
- Sensory input from the kidney travels to the T10 -11 levels of spinal cord and is sensed in the corresponding dermatome. thus, pain in the flank region may be referred from corresponding kidney.
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