Main components of the human endocrine system and the effects of their secretions

Hormone-secreting cells are also present in the glandular epithelia of the stomach, small intestine, liver, heart, kidneys, adipose tissue, skin, placenta, and other organs.Hormone-secreting cells are also present in the glandular epithelia of the stomach, small intestine, liver, heart, kidneys, adipose tissue, skin, placenta, and other organs.

Pineal gland
• Melatonin (affects sleep/wake cycles)
Thyroid gland
• Thyroid hormone (affects development, metabolism)
• Calcitonin (lowers blood calcium level)
Thymus gland
• Thymosins, thymulin
(enhance immune function)
Adrenal glands
Adrenal cortex
• Cortisol (affects metabolism,
immune response)
• Aldosterone (acts in kidneys)
Adrenal medulla
• Epinephrine, norepinephrine (cause
fight–flight response)
Gonads: ovaries or testes (not shown)
• Estrogens, progesterone, testosterone (regulate gamete production
and influence secondary sexual traits)
Pancreas
• Insulin (lowers blood glucose)
• Glucagon (raises blood glucose)
Pituitary gland
Anterior lobe makes and secretes:
• Adrenocortocotropic hormone
(ACTH; stimulates adrenal gland)
• Thyroid-stimulating hormone
(TSH; stimulates thyroid gland)
• Luteinizing hormone (LH;
stimulates ovaries and testes)
• Follicle-stimulating hormone
(FSH; stimulates ovaries,testes)
• Prolactin (stimulates mammary
glands)
• Growth hormone (affects growth)
Posterior lobe secretes:
• Antidiuretic hormone (ADH; acts
on kidney; concentrates urine)
• Oxytocin (makes smooth muscle
of reproductive tract and milk
ducts contract)
Hypothalamus
• Hormones that regulate pituitary’s
anterior lobe
• Antidiuretic hormone (ADH), and
oxytocin (both released by the
posterior Parathyroid glands (not shown, on rear of thyroid) pituitary)
• Parathyroid hormone (raises blood calcium level)