Hormones

Kidneys remove waste material from body and carry out osmoregulation

• blood passes through RENAL ARTERY into kidney
• liquid and dissolved substances are filtered out by CORTEX
• water and other substances are reabsorbed by the MEDULLA
• remaining water and dissolved substances pass to URINE to be collected in the RENAL PELVIS
• urine passes into URETER
• urine  stored in BLADDER
• urine leaves through URETHRA

ADH is the hormone released by the brain which controls the amount of water reabsorbed by the kidneys 

• when water levels are LOWER than normal then ADH is produced 
• the ADH causes the MEDULLA to reabsorb MORE water from the urine, back into the blood
• PRODUCES A LOWER VOLUME OF MORE CONCENTRATED URINE, which returns water levels to normal

• when brain detects HIGHER than normal then opposite happens
• LESS OR NO ADH is produced, medulla absorbs less water from urine to blood which PRODUCES A LARGER VOLUME OF LESS CONCENTRATED URINE

Insulin is a hormone that LOWERS blood glucose concentration. Special cells in PANCREAS releases it in response to high glucose.

• the target for insulin is the LIVER
• it creates an INCREASED absorption of the glucose from the blood
• it converts the EXCESS glucose into GLYCOGEN 
• this glycogen is MAINLY STORED in the liver and partially in muscle cells
• there is INCREASED respiration
• NEGATIVE FEEDBACK: a mechanism to ensure the concentration or level of something doesn't deviate too far from the normal value.. INCREASING THE HORMONE HAS THE OPPOSITE (NEGATIVE) EFFECT ON WHAT IS BEING MONITORED