Excretory system Flashcards
functions of the excretory system
- removal of waste
- balance blood pH (7.3)
- maintensnce of water balance
components of the excretory system
renal artery, renal veins, kidneys, ureters, bladder, urethra
renal artery
delivers blood to the kidneys
renal veins
returns filtered blood to the heart
kidney
filters blood to remove waste products
- weighs 0.5kg
- hold 25% of the bodies blood at one time
located beneath the digestive organs
- made up of three layers: cortex (outer), Medulla(inner), and renal pelvis (central mass where all veins and tubes connect)
ureters
transport waste from the kidneys to the bladder
bladder
stores waste(urine) and u lose control once it hits 600ml
urethra
removes waste product
waste products
- urea (2%)
- uric acid
- creatinine
(make up 5% of waste)
urea
- Amino acids are broken down by liver (deamination) producing ammonia
- Ammonia is extremely toxic (0.005 mg can kill a human)
- Ammonia binds with carbon dioxide and forms urea
uric acid
formed bt the breakdown of nucleic acids
creatinine
by product of muscle metabolism
PH balance
- During cellular respiration excess acids (e.g. citric and lactic acid) build up in the body
- These acids are ionized to produce H+ ions
- The build up of H+ ions lowers the pH of blood
H+ ions can removed from blood and combined with filtrate urine
water balance
- The average adult loses 2 liters of water a day (how much you should consume a day)
By urine, perspiration and exhalation - ADH (antidiuretic hormone) helps regulate water by causing the kidneys to increase water reabsorption(out of urine and back into the blood)
- When ADH is released more concentrated urine is produced, conserving body water
different stages of dehyrdation
A drop in fluid intake by 1% causes thirst, 5% causes u to collapse or feel dizzy/faint, 10% causes death