Compare Thyroxine & Adrenaline

THYROXINE: 1) Produced by thyroid gland, stimulates basal metabolic rate 2) controls the speed at which oxygen and food products react to release energy for the body to use 3) Controlled by negative feedback: Low thyroxine - hypothalamus releases TRH, this causes the pituitary to release TSH - blood levels return to normal. Normal thyroxine - inhibits hypothalamus to release TRH, this inhibits the pituitary to release TSH - blood levels remain to normal. ADRENALINE: 1) Not controlled by negative feedback 2) Its effects allow to prepare for quick response (where it may be essential)