Ta'lim innovatsiyasi va integratsiyasi
47-son_1-to’plam_Iyun -2025
175
ISSN:3030-3621
PATHOPHYSIOLOGY AND FUNCTIONS OF THE KIDNEYS: AN
INTEGRATIVE OVERVIEW
Turaev Umar Rahimovich
torayev.umarjon@bsmi.uz
Departments of Pathological Physiology
of Bukhara State Medical Institute
Abstract:
The kidneys are essential for maintaining internal homeostasis
through their roles in filtration, reabsorption, secretion, and hormone production.
Disruption in kidney function leads to a wide range of systemic complications. This
review discusses the primary physiological functions of the kidneys and explores the
underlying pathophysiological mechanisms in common renal diseases such as acute
kidney injury (AKI), chronic kidney disease (CKD), and glomerulonephritis.
Keywords:
kidney, nephrology, renal physiology, renal failure, glomerular
filtration, AKI, CKD
1. Introduction
The kidneys are paired bean-shaped organs located retroperitoneally on either
side of the vertebral column. Each kidney filters approximately 180 liters of plasma
daily, ensuring removal of metabolic waste, regulation of fluid and electrolyte balance,
and endocrine function. The kidneys play a pivotal role in maintaining systemic
homeostasis, and their dysfunction can be life-threatening.
2. Functions of the Kidneys
2.1 Filtration
The nephron, the functional unit of the kidney, filters blood through the
glomerulus. This ultrafiltration process is driven by hydrostatic pressure and
selectively permits water and solutes to pass while retaining proteins and cells.
2.2 Reabsorption and Secretion
After filtration, essential substances like glucose, amino acids, and electrolytes
are reabsorbed in the renal tubules. Waste products such as urea, creatinine, and drugs
are secreted into the tubules for excretion in urine.
2.3 Regulation of Electrolyte and Fluid Balance
The kidneys regulate sodium, potassium, calcium, phosphate, and water levels
in response to hormonal signals (e.g., aldosterone, antidiuretic hormone).
2.4 Acid-Base Balance
Through the reabsorption of bicarbonate and excretion of hydrogen ions, the
kidneys maintain blood pH within the normal range (7.35–7.45).
2.5 Endocrine Functions
Ta'lim innovatsiyasi va integratsiyasi
47-son_1-to’plam_Iyun -2025
176
ISSN:3030-3621
The kidneys produce erythropoietin (stimulates red blood cell production), renin
(regulates blood pressure), and convert vitamin D into its active form (calcitriol), which
is essential for calcium homeostasis.
3. Pathophysiology of Kidney Disorders
3.1 Acute Kidney Injury (AKI)
AKI is characterized by a rapid decline in renal function, often due to ischemia,
toxins, or obstruction. It is marked by elevated serum creatinine and decreased urine
output. Early intervention can lead to full recovery, but severe cases may progress to
chronic kidney disease.
3.2 Chronic Kidney Disease (CKD)
CKD involves progressive and irreversible loss of renal function over months or
years. Common causes include diabetes mellitus and hypertension. CKD leads to
accumulation of toxins, anemia, electrolyte imbalance, and increased cardiovascular
risk.
3.3 Glomerulonephritis
An inflammatory disorder affecting the glomeruli, glomerulonephritis can be
acute or chronic. It is often immune-mediated and presents with proteinuria, hematuria,
and reduced glomerular filtration rate (GFR).
3.4 Nephrotic and Nephritic Syndromes
Nephrotic
syndrome
involves
significant
protein
loss
in
urine,
hypoalbuminemia, and edema. Nephritic syndrome includes hematuria, hypertension,
and variable proteinuria, often secondary to glomerular inflammation.
4. Conclusion
The kidneys are vital organs responsible for a wide array of homeostatic
functions. Pathophysiological alterations in renal function can lead to acute or chronic
diseases with systemic manifestations. Timely diagnosis and management of renal
disorders are critical to prevent irreversible damage and improve patient outcomes.
Advancements in nephrology continue to enhance our understanding of kidney
function and disease.
References
1.
Brenner, B.M., & Rector, F.C. (2020).
Brenner and Rector's The Kidney
. Elsevier.
2.
Taal, M.W., Chertow, G.M., Marsden, P.A., et al. (2021).
Comprehensive Clinical
Nephrology
. Elsevier.
3.
Kellum, J.A., Lameire, N. (2018). Diagnosis, evaluation, and management of acute
kidney injury: a KDIGO summary.
Critical Care
, 22(1), 1–8.
4.
Levin, A., Stevens, P.E., Bilous, R.W., et al. (2017). Kidney disease: improving
global outcomes (KDIGO) guideline update.
Kidney Int Suppl
, 7(1), 1–59.
