Sunday, October 25, 2009

What are the similarities and differences between anterior and posterior pituitary hormones?

You should think of each hormone, whether from the anterioir or posterior pituitary as unique, with it's own unique set of functions and regulatory mechanisms.There are two hormones which come from the posterior pituitary: Vasopressin (also known as antidiuretic hormone) and Oxybutinin. Vasopressin main role is to make sure we have enough water flowing through our blood vessels, permitting normal blood pressures and delivery of the oxygen/nutrients to all our tissues. Oxybutinin is involved in the contraction of the uterus during delivery of a baby. Both of these hormones are actually made in the neurons of the hypothalamus (part of the brain), which is directly/physically connected to the posterior pituitary. They are made in the hypothalamus, but secreted by the posterior pituitary gland. (So the posterior pituitary can be thought of as an extension of the brain!)The anterior pituitary makes many more hormones, including thyroid stimulating hormone (regulates/stimulates the thyroid gland), prolactin (stimulates breast milk production), growth hormone (stimulates cellular growth and metabolism), luteinizing and follicle stimulating hormones (both are involved in the female menstrual cycle and ovulation), and adrenocorticotrophic hormone (stimulates/regulates the adrenal gland). Each of these hormones have unique activaties and regulatory mechanisms...they just happen to be made close to each other within the body (the anterior pituitary).
Each hormone is unique in the body. you cant give more imp to one or less imp to another.
Ant. Pituitary hormones are controlling hormones of other endocrine glands in body. like ACTH regulates hormones of adrenal glands, TSH regulates thyroid hormones, etc.
Post pituitary have 2 hormones- Vasopressin( ADH) is very critical for maintaining urine osmolarity. and other is Oxytocin which is important at the time of labour(child birth) maintaining utrine contractions.
other difference between them is ant pituitary hormones are released by the controll of hypothalamic hormones which are called Releasing hormones, for ACTH it is ACreleasing hormone, for TSH it is TRH. while post pituitary are manufactured in hypothalamus and carried to post pituitary and then released from there.
You can go to and can find out more about this hormones.
Much of What is Written Above is True, my Additions would Be Negative Feedback of The Ant. Hormones and POMC.

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