Urea and Uric Acid Excretion/

Urine Composition

DaYea, Christina

Urea

Urea: By-product of amino acids catabolism Plasma concentration reflects the amount of

protein Urea enters the renal tubule by filtration 50% of urea is reabsorbed

Remainder is excreted in urine

Uric Acid

Uric Acid: Product of the metabolism of certain organic bases in nucleic acids Active transport reabsorbs the uric acid in

glomerular filtrate Small amount is secreted into the renal tubule

and is excreted in urine

Urine Composition Reflects the amounts of water and solutes

that the kidneys eliminate from the body

Retains in the internal environment to maintain homeostasis

Due to variations in dietary intake and physical activity, the composition may differ form time to time Water (95%), urea and uric acid Electrolytes, amino acids

Urine Composition Volume of urine

produced is usually between 0.6 and 2.5 liters per day Depends on fluid

intake, environmental temperature, relative humidity, emotional condition, respiratory rate, body temperature

Normal output is 50~60 milliliters per hour Less than 30 ml per

hour may indicate kidney failure

Review The urea enters the ______________ by filtration

___________ is a by-product of amino acid catabolism

____________ is a product of the metabolism of certain organic bases in nucleic acids

Urine is about 95% __________, and usually contains _______ and ___________ acid

Urine composition reflects the amounts of _____ and solutes that the _________ must eliminate from the body or retain in the _________ ___________ to maintain ________________.

renal tubule Urea

Uric Acid

wateruricurea

kidneys

water

internal environment homeostasis