Disorders Of The Excretory System
Animals by metabolic activities collect ammonia, urea, uric acid, carbon dioxide, water and ions such as Na+, K+, Cl–, phosphate, sulphate, etc. These substances need to be removed. Nitrogenous wastes such as ammonia, urea, and uric acid are excreted by the animals. Ammonia is more destructive than uric acid. Hence, ammonia needs a large amount of water and uric acid needs less amount of water for its elimination. Ammonotelism is the procedure of excreting ammonia. Numerous bony fishes, aquatic amphibians, and aquatic insects are ammonotelic in nature. Ammonia is normally excreted by diffusion across body surfaces or through gill surfaces (in fishes) as ammonium ions because ammonia is willingly soluble. For its removal, kidneys do not play any remarkable role. Terrestrial conversation required the manufacturing of lesser destructive nitrogenous wastes such as urea and uric acid in order of conserving water. Mammals, numerous terrestrial amphibians, and marine fishes mostly excrete urea and are called Ureotelic animals. Ammonia manufactured by metabolism is changed into urea in the liver of these animals and free into the blood, which is purified and excreted out by the kidneys. Some quantity of urea possibly continued in the kidney matrix of some of these animals to keep a wanted osmolarity. Reptiles, birds, land snails, and insects excrete nitrogenous wastes as uric acid in the shape of pellets or paste with a minimal loss of water and are called uricotelic animals.
For the removal of waste products from the human body to keep homeostasis, an excretory system is necessary. Through metabolism, these products are formed and removed in the form of sweat, urine, and feces. In the process of excretion, some excretory organs include kidneys, sweat glands, liver, and large intestine. When one or more excretory organs stop working properly. It causes excretory disorders.
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 H+ ammonium 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
- Little treatment time and least interruptions of lifestyle between treatments.
- Patients can guide to a greater extent or smaller normal life.
- It can too help in the recovery of reversible kidney injury.
- No part of the apparatus is the shaped interior of the body.
- Bacteria and viruses are unable to go through it.
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 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 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.
FAQ on Excretory Disorders
Question 1: What is acute renal failure?
Acute renal failure is normally adjustable and usual renal functioning can be brought back and the patient has to go through systematic dialysis.
Question 2: Which disease is most commonly associated with renal acute failure?
Uraemia is most commonly associated with renal acute failure.
Question 3: Define haemodialysis.
Haemodialysis utilize the procedure of diffusion over a semipermeable membrane to detach undesirable, poisonous material from the blood while attaching desirable elements.
Question 4: What is an artificial kidney?
A dialysis machine or artificial kidney is attached to the patient’s body. It is worked in the case of uraemia ( blood with excess urea ). In this, blood from an artery of the patient is redirected by dialysing membrane afterwards it to 0° C and intermixing with an anticoagulant ( heparin ).
Question 5: What are calculi?
Renal calculus also called a 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.
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