Excretory system

Urinary, urinary system includes upper and lower urinary tract. Bodies belonging to the excretory system: kidneys, ureters, bladder, urethra.

Basic functions urinary system

  • Excretion – urine production and elimination of waste products, including products of nitrogen metabolism.
  • Osmoregulation – control the volume of water, salt to maintain a balance in the internal environment and blood pressure.
  • Maintaining acid-base balance – pH stability

Dates associated with urination

  • The formation and excretion of urine – diuresis runs continuously.
  • Pledge of urine – anuréza.
  • Increased production and excretion of urine – polyuria.
  • Reduced production and excretion of urine – oliguria.
  • Urinary frequency – micturition.


Urine is happening in the upper urinary tract, the functional unit of the kidney – the nephron, composed of glomerular and tubular ball, canals.

It happens when urine production

Glomerular filtration (ultrafiltration), which occurs approximately 150 liters per day, containing e and substances needed by the body, amino acids, sugars, vitamins.

Tubular resorption – absorption of substances in the renal tubules of the primary urine absorbed water, salts, glucose, NaCl, vitamin C, amino acids, concentrated wastes, urine is concentrated, is formed about 1.5 l final urine per day.

On the production of urine affect

  • Blood pressure
  • composition of plasma
  • Vasopressin – a hormone that reduces urine output increases the reabsorption of water and its shortage causes žíznivku, diabetes insipidus.
  • Aldosterone – acts on electrolytes in urine, increases the reabsorption of sodium and water, increasing the secretion of potassium.
  • nerve effects

composition of urine

95% water, urea, NaCl, inorganic ions, waste substances, the body absent

The urine may be sugar, blood, pathogens, proteins