Endocrine

Just like other hormones, steroid hormones are produced by an endocrine gland. They are fat-soluble and can diffuse through the cell membrane. Once they are in the reach of the nucleus of a cell, they bind onto a particular receptor in the substance chromatin. When the chromatin and the hormone are bound together, they initiate replication of mRNA. This effect on genes leads to production of some reproductive hormones such as estrogen through translation. The genes do this through the process of coding (Burnstein 65).

An Antagonistic hormone pair refers to two hormones each with an effect contrary to the other hormone. One example of these pairs is glucagon and insulin. Insulin is produced in the pancreas and decreases the blood sugar level. The hormone induces the liver to covert glucose into glycogen. On the other hand, the pancreas produces glucagon. It acts on the liver and makes it to convert glycogen into glucose when blood sugar level is too low. Another antagonistic hormone pair is the calcitonin and parathyroid (PTH). Calcitonin is produced by the thyroid gland, and lowers blood calcium level. This is achieved through the action on bones, kidneys and intestines. The parathyroid is produced by parathyroid glands. It acts on kidneys, intestines and the bone tissue. The parathyroid gland raises the blood calcium level (Pandit 236).

Synergetic hormones interact with each other to produce either an amplifying effect or a neutralizing effect. The parathyroid and growth hormone are synergetic. When both hormones are released into the bloodstream, they enhance the mechanical properties of the human body. These hormones primarily act on the bone structure (Parker 120).

Testosterone and estrogen is another example of synergetic hormones. These hormones neutralize the effect of each other. A person with more estrogen than testosterone will exhibit female characteristic while one with more testosterone will exhibit male characteristics. These hormones have an effect on all reproductive organs and other parts of the human body (Parker 89).