The human endocrine system

We can think of the endocrine system as a group of messengers (hormones) that tell our bodies what to do, such as to grow, to take up sugar or release it, when to sleep, or, for example, when to channel blood to specific organs to aid in the fight or flight response which is orchestrated by the adrenal medulla when it produces epinephrine.

The major endocrine glands, their main hormones and main functions (working from the top down):

1. The Hypothalamus – hunger, moods, body temperature, sex drive, sleep, thirst [AFH (Anti-diuretic hormone), OT (Oxytocin)]
2. The Pituitary (anterior lobe and posterior lobe) – growth and reproduction, controls other endocrine glands [Vasopressin (antidiuretic hormone), Corticotropin (ACTH), Growth Hormone (GH), lutenizing hormone and follicle stimulating hormone, Oxytocin, Prolactin, Thyroid stimulating hormone]
3. The Pineal – sleep patterns, onset of puberty [Melatonin, Adrenoglomerulotropin]
4. The Thyroid –growth patterns, metabolism, energy levels [Thyroid hormone, Calcitonin]
5. The Parathyroid – controls calcium levels in the body [Parathyroid hormone]
6. The Thymus – influences production of T-lymphocytes [TF (Thymic factor), Thymosin, THF (thymic humoral factor), Thymopoietin]
7. The Pancreas – orders the take up, or release of glucose [Glucagon and Insulin]
8. The Adrenals (cortex and medulla), speed up or slow down the body, response to stress, regulate metabolism [Aldosterone, Cortisol, DHEA, Epinephrine and Norephinephrine]
9. The Male (testis) and Female (ovary) Gonads – production of male and female sex hormones [Testosterone (men, Estrogen and Progesterone (women)]

The glands of the endocrine system secrete hormones directly into the bloodstream where they travel around the body affecting other cells and systems. Hormones are much smaller than cells, and can’t be seen as easily as blood cells can be, for example. (Reference: The Discovery Channel) The word, hormone means to ‘spur on’. These chemical messengers help to maintain homeostasis by influencing chemical changes in the body.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s