Wednesday, March 11, 2009

Wednesday’s class covered the material that will be on our next quiz—information over the endocrine system and autonomic nervous systems. We discussed the Adrenal glands, the medulla and cortex, as well as the hormones each releases and the location from which they’re released. We also covered the thyroid glands and how follicular, parafollicular, and colloid cells come into play. The follicular cells produce T3 and T4 (Thyroxine) from molecules of “DIT” and “MIT.” Thyroxine affects our BMR, or, basal metabolic rate. We also discussed the different tracts that luteinizing hormone takes in males versus females, starting from the hypothalamus. Our discussion also covered the parasympathetic and sympathetic nervous systems. We talked about the cranial nerves that have parasympathetic fibers and also discussed the pre/post-ganglionic fibers of the sympathetic nervous system and the different neurotransmitters that can be released. Lastly, we discussed the pathway of the cAMP/PKA secondary messenger system pathway.

Thyroxine, which is released by the thyroid gland, plays a major role in the regulation of your metabolism. Too much thyroxine (hyperthyroidism) can result in weight loss, nervousness, and/or anxiety and too little thyroxine (hypothyroidism) can result in sluggishness and weight gain. In order to treat both disorders doctors use prescribed medication. In the case of hyperthyroidism, too much T3/T4 is being produced, thus, a medication called an anti-thyroid drug is taken, which blocks the release of some thyroxine. Smaller amounts of thyroxine are still produced, but in much smaller quantities than before. In hypothyroidism, individuals are prescribed synthetic, man-made thyroxine, which mimics the effects of the natural hormone. In both cases it is common for the individual to be on these medications for life (in some hypothyroidism cases, however, individuals can regain thyroid function).