Disorders of Excretory System – Class 11 | Chapter – 19 | Biology Short Notes Series PDF

Disorders of Excretory System: The excretory system is responsible for removing wastes from the body. Disorders of the excretory system can include problems with the kidneys, bladder, or bowels. Symptoms of a disorder of the excretory system can include fatigue, nausea, vomiting, and changes in urine or bowel habits. Treatment for a disorder of the excretory system may include medications, dietary changes, or surgery.

Disorders of Excretory System


Haemodialysis utilizes the procedure of diffusion over a semipermeable membrane to detach undesirable, poisonous material from the blood while attaching desirable elements.  A continuous flow of blood on one side of the semipermeable membrane and a cleaning solution (dialysate) also permit the moving of waste products from the blood. 

In this method, a dialysis machine or artificial kidney is attached to the patient’s body. It is worked in the case of uremia (blood with an excess of urea). In this, blood from an artery of the patient is redirected by dialysing a membrane after refrigerating it to 0°C and intermixing it with an anti-coagulant (heparin). Dialysing membrane has openings identical to those of glomerular capillaries and functions as a superfine strainer. This cellophane membrane is impermeable to macromolecules such as plasma proteins but is permeable to micromolecules such as urea, uric acid, creatinine, and mineral ions. This tune is submerged in a solution called dialysate. Dialysate is isotonic to blood plasma except for the nitrogenous wastes, for which it is hypotonic to blood plasma. In consequence, the wastes such as urea, uric acid, creatinine, excess Hammonium salts, etc. from blood spread over the membrane into the dialysate. The dialysate is swapped as and when needed. Blood from the dialyser goes back to the body by a vein after warming it to the body temperature and combining it with an antiheparin.

Advantage of Haemodialysis 

  1. Little treatment time and least interruptions of lifestyle between treatments.
  2. Patients can guide to a greater extent or smaller normal life.
  3. It can too help in the recovery of reversible kidney injury.
  4. No part of the apparatus is the shaped interior of the body. 
  5. Bacteria and viruses are unable to go through it. 

Renal Failure

Renal failure is distinguished by the worsening of the working of the kidneys which consequences in the collection of dangerous nitrogenous wastes such as urea major to uremia, and distinct depletion in urine product. It is of two types:

  • Acute renal failure is normally adjustable and usual renal functioning can be brought back, and the patient has to go through systematic dialysis 
  • Chronic renal failure is distinguished by irreversible defective kidneys, and the patient may need to go through renal transplantation.

Renal transplantation includes shifting of kidney from one person to another. The transplant is normally removed from a dead person or from siblings or close relatives to expand the possibilities of successful transplantation. It also includes ABO (blood group) compatibility; HLA (Human Leucocyte antigen) compatibility and the use of immunosuppressants. Immunosuppressants are chemicals such as antimetabolites, alkylating agents, cyclosporin, adrenal corticoids, etc. which confront the refusal of a transplant kidney. 

Renal Calculi

Renal calculus also called renal stone includes the development of solid stone-like masses in renal tubules or renal pelvis, mostly because of the collection of insoluble crystals of salts such as sodium oxalates and a few phosphates. These give rise to serious hurting circumstances called renal colic. It is more usual in men than women. It can conduct anuria and haematuria. Renal stones can be detached by the techniques like pyelolithotomy or lithotripsy. 


It is also called Bright’s disease and is distinguished by inflammation of the glomeruli of both kidneys and is normally post-streptococcal, mainly in children. The main indications are haematuria, proteinuria, and salt and water retention. Some may guide to oliguria, distinct hypertension, and pulmonary oedema. Particular suggested actions are: bed rest, increases fluid intake, use of diverters, more intake of carbohydrates, and use of antibiotics.


In uremia, the accumulation of urea is high as compared to a normal person. In this patient, by haemodialysis urea in excess amount is removed. In haemodialysis, the blood is stained carefully from where the artery is suitable and then sent to the dialysing unit. The dialysing unit contains a membrane with pores that permit the movement of molecules on the basis of a concentration gradient.

Nephritis or Bright’s Disease 

It is usually inflammation of the kidney. By inflammation in the glomeruli of the kidney, Glomerulonephritis is identified. In this case, the glomeruli are fully filled in blood. When so many glomeruli stop functioning, then the patients required an artificial kidney.

Hypertension due to Renin Secretion 

Hypertension is caused by the formation of angiotensin as a result of the hypersecretion of renin.

Renal Tabular Acidosis 

In this condition, the patient cannot secrete optimum quantities of hydrogen ions due to this large amount of sodium bicarbonate ions being lost while urination.

Diabetes Insipidus 

Diabetes insipidus is caused by the deficiency of the antidiuretic hormone. These hormones help in the reabsorption of water by different parts of the nephron and prevent diuresis. Non-efficient ADH secretion caused excessive production of dilute urine and intense thirst.


It is an accumulation of excess fluid in the tissues. Excess sodium ions cause an expansion in the interstitial fluid volume without a change in osmolality. 

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By Team Learning Mantras