Pattern of hormone secretion in animals
Fluctuations of frequency and amplitude of hormone secretion is described as hormone peaks, pulses, spikes or bursts these are called Pattern of hormone secretion in animals.
The rhythm of hormone secretion may be one the following-
Ultradian-
Ultradian pattern of hormone secretion have many short pulses occurring every few minutes to few hours each day (Adrenaline and noradrenaline).
Circadian-
In circadian, peaks occur approximately once in 24 h (cortisol peaks in early morning)
Infradian-
In Infradian, pulses take more than a day but less than a year to occur (preovulatory surge of LH in dogs once in 6 months)