How can we classify endocrine glands according to their hormone type?

Steroid secreting: (androgens, estrogen) abundant with SER and mitochondria and lipid vacuoles. their lipid type makes them diffuse freely through plasma membrane without exocytosis. THYROID: synthesize thyroglobulins liposoluble hormones (T3 and T4) diffuse freely through plasma membrane Peptides : water soluble hormones (insulin) are released via exocytosis characterized by abundant RER Amino acid derivatives: (serotonin, melatonin) water soluble hormones rejected by exocytosis