The structure of the kidney in the human body

The human body is a work of biological art and the kidneys are a big part of that. Two bean shaped organs. They filter blood and remove waste, balance blood chemistry and produce hormones. Whether you’re a medical student trying to learn human anatomy or a health enthusiast looking to learn more, you need to know the structure and function of the right and left kidney.

This article will cover the anatomy, function and importance of the kidneys and blood pressure and also their role in overall health.

Kidney Anatomy and kidney location

The bean shaped organs—situated on either side of the spine just below the ribcage—normal organ weights are roughly the size of a fist and weigh about 4-5 ounces each. Despite their small size their impact on the body is huge. To understand kidney position and how kidneys work and regulate blood pressure you need to first understand their structure and kidney diagram and renal function.

External Features

Renal Capsule: The renal capsule is a thin fibrous layer that surrounds and protects the kidneys. It acts as a barrier against trauma and infection and provides structural support to the delicate kidney structures.

Hilum: The renal hilum of kidney is the indented area on the concave side of each kidney. It is the entry and exit point for vital structures such as the renal arteries which supply blood to the kidneys, the renal veins which carry filtered blood away from the kidneys and the ureters which transport urine from the kidneys to the bladder.

Internal Features

Renal Cortex

The renal cortex is the outer part of the kidney and contains millions of nephrons, the functional units of renal cortex that filter blood and produce urine.Renal cortex is involved in the initial stages of urine formation by filtering waste products, excess water and electrolytes from the blood.

Renal Medulla

Located beneath the renal cortex, the renal medulla has several renal pyramids. These cone shaped structures have tubules that concentrate urine and transport it to the renal pelvis, the area where urine collects before it goes to the ureters for elimination. The renal medulla regulates the concentration of urine and maintains water balance in the body to prevent kidney failure.

Renal Pelvis

This is where the urine collects before it goes to the ureter, blood vessels which carries it to the bladder for excretion to tiny blood vessels.

Nephron Structure: The Smallest Unit of the Kidney

What is a Nephron, nephron diagram?

A nephron is the smallest unit of the kidney, each left and right kidney has about one million nephrons. Each nephron filters waste and excess substances from the blood.

Nephron Components

Renal Corpuscle

• renal corpuscle is located in the renal cortex which has renal fascia this structure has:
• Glomerulus: A glomerulus is a system of capillaries that filters blood.
• Bowman’s Capsule: surrounds the glomerulus, collecting the filtrate.

Bowman’s capsule is also part of the nephron, encloses the glomerulus, filters blood to form primary urine from two kidneys.

Renal Tubule

A renal tubule is a winding tube where filtrate undergoes reabsorption and secretion to form urine. It has three parts:

• Proximal Tubule for reabsorption of substances like glucose and amino acids.
• Loop of Henle, for water and salt balance.
• Distal Tubule, fine tunes the salt and water composition in urine.

1. Capillary Network

Surrounding the renal tubules, this network allows exchange of substances between blood and the filtrate.

How Nephron works

A nephron works through three processes:

• Filtration at the glomerulus to remove waste and excess substances.
• Reabsorption in the tubules and glomerulus to return essential nutrients like glucose and water to the bloodstream by renal veins.
• Secretion to release more waste and toxins into the filtrate.

Blood Supply to the Kidneys

Blood is the life source of the kidneys’ filtration process.The blood flows also does blood pressure regulation.Blood is the life source of the kidneys’ filtration process. The right kidney along with the left kidney plays a role in the process through a network of tiny blood vessels, for efficient waste removal and blood pressure regulation.

Kidney circulation involves:

Renal Artery

Blood loaded with waste enters the kidney through the renal artery. This blood flows through the nephrons for filtration.The renal artery brings oxygen rich blood to the kidneys for efficient filtration and waste removal.The renal artery supplies blood to the kidneys. The left kidney is covered by the renal fascia, a protective layer that keeps it stable and functioning.

Renal Vein

After filtration, the blood exits the kidney through the renal vein and back to the circulation.

The kidneys get 20% of the heart’s output, hence their importance in overall health.

renal pyramid

The renal pyramid in the kidney’s medulla has nephron’s tubules and collecting ducts. Renal pyramid concentrates the urine and carries it to the calyces and then to the renal veins which drains into the renal pelvis.

Kidney Problems

Knowing the human kidney structure is important in diagnosing and managing many common conditions:

Kidney health is important for overall well being and knowing common kidney problems is important for early diagnosis and management.

Chronic Kidney Disease (CKD):

Chronic Kidney Disease is a progressive condition where the kidney function declines gradually. It is often associated with underlying health conditions like hypertension and diabetes. As the kidneys fail to filter waste and excess fluids from the blood, toxins will accumulate and can cause kidney transplant complications and kidney infection. Early detection and management of chronic kidney disease is important to slow down its progression and minimize further damage.

Kidney Stones:

Kidney stones are hardened mineral deposits within the kidneys. They can be small or big and can cause severe pain as they pass through the urinary tract. Dehydration, dietary factors and underlying medical conditions can contribute to the formation of kidney stones. Treatment options range from increasing fluid intake and pain management to extracorporeal shock wave lithotripsy or surgical removal.

Urinary Tract Infections (UTI):

Urinary Tract Infections occur when bacteria enters and compounds in the urinary system. UTI can affect any part of it, including the bladder, when the infection reaches the kidneys it can cause more severe symptoms and can lead to complications and kidney infection. Early detection and treatment with antibiotics is important to prevent the infection from progressing and causing further damage.

Now that we know these common kidney problems, we can recognize the symptoms and seek medical attention. Regular check-ups, good hydration and healthy lifestyle can also contribute to kidney health and overall well being. Remember early intervention is key to better outcome so don’t hesitate to consult a doctor if you have concerns about your kidney health.

Polycystic kidney disease:

Polycystic kidney disease (PKD) is a genetic condition where fluid filled cysts grow in the kidneys. These cysts will impair kidney function over time and can lead to kidney failure. Symptoms are high blood pressure, back pain and urinary problems. PKD can also affect other organs and requires medical management or transplantation.

nephrotic synd:

Nephrotic syndrome, a condition that affects the kidneys, two bean shaped organs, disrupts their ability to filter blood. It impairs blood flow mainly to the right kidney and its renal artery branches. This condition causes protein loss in urine, swelling and requires medical intervention to maintain kidney function. The renal artery enters the kidneys to supply them with blood to keep the kidneys healthy and functioning well. The cortical radiate arteries further distributes blood within the kidneys to maintain healthy kidney function and prevent complications like kidney failure.

Who is most at risk of kidney problems?

People with the following conditions are at higher risk:

• Diabetes or hypertension and high blood pressure
• Family history of kidney disease like kidney cancer
• Overuse of certain medications like NSAIDs

What do the kidneys do?

The kidneys are multi functional organs doing more than just filtering waste. Here’s an overview of measuring kidney function:

1. Blood Filtration

The kidneys filter 180 liters of blood daily, removing waste and excess fluids. Once filtered, waste products are channeled into the ureters, transported to the bladder and excreted through urine.

1. Blood Pressure Control (BP check up)

The kidneys are amazing organs that do more than just filter waste, they also form and excrete urine, regulate blood chemistry and control blood pressure. They maintain the body’s acid base balance, electrolyte levels and fluid balance. Knowing the many roles of the kidneys will make you realize how important they are to overall health and well being and reducing renal failure.

3 . Regulate Blood Chemistry

• Maintain the body’s acid base balance (pH levels).
• Regulate electrolytes (sodium, calcium and potassium).

1. Blood Pressure Control

Also the kidneys help in maintaining fluid balance by regulating the amount of water reabsorbed into the bloodstream. Through a complex mechanism involving hormones like antidiuretic hormone (ADH) and aldosterone, the kidneys make sure the body has enough water to function well and eliminates excess fluids. This delicate balance maintains proper hydration and overall bodily function. Also the kidneys help in bone health by activating vitamin D which is important for calcium absorption and bone formation. In short the kidneys are amazing organs that do many essential functions to support overall health and kidney disease and well being.

1. Hormone Production

• Calcitriol (active Vitamin D): For calcium absorption.
• Erythropoietin (EPO): For red blood cell production.

1. Glucose Production

The adrenal glands situated above each kidney are part of the body’s stress response system. They secrete cortisol and other hormones to help the body manage stress, regulate blood sugar levels, reduce inflammation and promote overall well being. Cortisol is called the “stress hormone” and plays a big role in many bodily functions to support the body’s response to stress and balance.

1. Stress Response

The adrenal glands above each kidney is part of the body’s stress response system. These glands secrete cortisol and other hormones to help the body cope with stress, regulate blood sugar levels, reduce inflammation and promote overall well being. Cortisol is called the “stress hormone” and helps manage stress by influencing many bodily functions and systems.

Can you live without a kidney?

Yes, humans can live with one functioning kidney. When one kidney is removed or fails the other kidney compensates by filtering more blood, showing how amazing the kidney is.

Now that you know the kidney anatomy and function, medical students and health enthusiasts can see how important these organs are to overall health. Take care of your kidneys by drinking regularly, eating healthy and avoiding excessive medications. Be proactive in taking care of your kidney health whether you are preparing for a medical career or simply for your own well being for a healthier and balanced life. Remember your kidneys are keeping your body in balance so take care of them.

Kidney Health and Conclusion

Your kidneys work hard to keep your body in balance and function. Drinking regularly, eating healthy and avoiding excessive medications are simple habits to support kidney health.

Now that you know the kidney anatomy and function, medical students and health enthusiasts can see how important these organs are to overall health. Interested to learn more? Be proactive—whether you are preparing for a medical career or for your own well being, the kidneys are worth it.