Anatomy Week Nine

Furthering what we learned about the endocrine systems and hormones, we learned that there are chemical classes of these hormones.  The hormones can be further divided into two main classes which are those that are soluble in lipids, and those which are soluble in water.  These two categories of hormones exert their effects on their target cells differently.  

Lipid soluble hormones include steroid hormones, thyroid hormones, and nitric oxide.  The steroid hormones are derived from cholesterol, and the two thyroid hormones are synthesized by attaching iodine to an amino acid called tyrosine.  Nitric oxide, which is a gas, is both a hormone and a neurotransmitter.  

The majority of the water soluble hormones are amine, peptide, and protein hormones.  Amine hormones are synthesized by modifying certain amino acids, and they are called this because they retain an amino group.  Peptide hormones consist of amino acids in chains of three to forty-nine.  The protein hormones are much larger and include fifty to two hundred amino acids.  

So we learned that there are several different types of hormones that all work together to maintain homeostasis in the body.  They are made from different sources, however, and thus are synthesized and processed differently from one another.  Each hormone has a different action on the body and has different effector cells that it activates.  Some people have deficiencies in hormone levels, and because of this different functions in the body are effected depending on the hormone deficiency.  An example of this would be hypothyroidism, which is an under-functioning of the hormones produced by the thyroid gland.