Mollie+M.

January 17th 2016 __ The Endocrine system: the Thyroid gland __

The endocrine system is the collection of glands that produce hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things. In general, a gland selects and removes materials from the blood, processes them and secretes the finished chemical product for use somewhere in the body. The endocrine system affects almost every organ and cell in the body.

__ How does the thyroid gland work? __ The thyroid is part of the endocrine system, which is made up of glands that produce, store, and release hormones into the bloodstream so the hormones can reach the body's cells. The thyroid gland uses iodine from the foods you eat to make two main hormones: It is important that T3 and T4 levels are neither too high nor too low. Two glands in the brain—the hypothalamus and the pituitary communicate to maintain T3 and T4 balance. The hypothalamus produces a releasing hormone that signals the pitu itary to tell the thyroid gland to produce more or less of T3 and T4 by either increasing or decreasing the release of a hormone called thyroid stimulating hormone. __ Thyroid diseases __
 * Triiodothyronine (T3) [[image:smithlhhsb122/8966.jpg width="175" height="141" align="left" caption="The placement of the Thyroid gland"]]
 * Thyroxine (T4)

Cells in the thyroid sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous, or benign, conditions such as hypothyroidism, hyperthyroidism, thyroiditis and thyroid nodules.

There are several different disorders that can arise when the thyroid produces too much hormone (hyperthyroidism) or not enough (hypothyroidism). In some cases, changes to different types of thyroid cells can cause thyroid cancer. The most common type of thyroid cancer is called papillary thyroid cancer, which makes up about 70% of all thyroid cancers. Thyroid cancer begins in the thyroid gland and starts when the cells in the thyroid begin to change, grow uncontrollably and eventually form a tumor. [[image:smithlhhsb122/Capture.JPG width="295" height="24" align="left" caption="The difference between a healthy vs inflamed thyroid "]]

__ Treatments __ Thyroid diseases are very curable. In situations that involve cancer, they can be easily treated with surgery and the success rate is very high. There are many medications and various other treatments that can be done for various issues.

media type="youtube" key="Dc75xtuEzXw" width="560" height="315" References: [] []d[][][] Articles: __ http://www.cancer.ca/en/cancer-information/cancer-type/thyroid/thyroid-cancer/?region=on __ [|http://www.cancer.ca/en/cancer-information/cancer-type/thyroid/thyroid-cancer/?region=on#ixzz3xXEW2r1j] [] [] __ [] __ November 11, 2015 __** Human Tails? **__

Jean-Baptiste Lamark proposed a theory in the early 1800’s about evolution and how he believed that traits amongst living organisms were created or gotten rid of (use and disuse). Although his theory was wrong, the evolution of traits adapting or changing over time is very true.

Humans have lots of unused functions, or vestigial traits, nowadays. For example, the wisdom teeth. One of these is known as the tailbone or coccyx. The tailbone is now just a remnant of what was once a tail. All mammals have a tail at one point in their development, and for humans it’s during the first 14-22 weeks in the uterus. The tailbone has lost its original use in assisting in balance and mobility, though it still serves some secondary functions such as being an attachment point for muscles.

In rare cases, the tail we begin to grow in those early stages as a fetus can continue to develop. Thirty three cases of human babies born with this defect have been reported since 1884. These babies were born with tail-like growths around twelve centimeters long and were surgically removed. These tails are sometimes able to move and contract and it happens twice as much in males as it does in females. It’s made up of blood vessels, nerves, connective tissue, central bundles, and is covered in skin. Although bone, cartilage, notochord, and spinal cord are missing. In other words, if humans have a bony tail, it's not a "true tail", it's a "pseudo-tail" because of other abnormalities, but if it's a "true tail", it contains bone, cartilage, notochord, or spinal cord. And no human tail contains vertebrae.

Even though Lamarks theory wasn't correct, and these growths may not be considered real tails, they are an evolution of what may have been something like a tail to our ancestors.

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__References __ - [] - [] - [] - []

__Articles __ - http://www.gennet.org/index.php?option=com_content&view=article&id=56:the-human-tail-and-other-tales-of-evolution&catid=8:mac-speakers - http://www.evolutionnews.org/2014/05/are_humans_ever085411.html - http://www.discovery.org/a/23041

- http://www.researchgate.net/publication/223980442_A_Gelatinous_Human_Tail_With_Lipomyelocele_Case_Report

October 20th, 2015 **__ The Evolution of Blue Eyes __** Eyes are beautiful things. Each person has a unique color of either brown, blue, hazel or green eyes. Nowadays, no one questions these colors, they seem completely normal. However, some colors have developed from genetic mutations over our history and were not always thought of as normal.

Originally everyone was believed to have had brown eyes. Blue eyes only started popping up everywhere around 10,000 years ago and are believed to all have come from one single ancestor. Only an estima ted 8% of the world has blue eyes and between 20% - 40% of Europeans have blue eyes.

__ How the genes work __

Eye color is determined by the amount of pigment in your iris, and the pigment is determined from genetics. If you have a lot of pigment, you probably have brown eyes, less pigment means green or hazel, and little to no pigment means that you have blue eyes. There are up to 16 genes responsible but there are two main genes that are in charge of your eye color, HERC2 and OCA2. The HERC2 gene acts as a switch to activate the OCA2 gene, and the OCA2 activates the proteins that create the melanin pigments. If the mutation occurs, it will stop the OCA2 from being able to create the proteins necessary for pigmentation. (Visual representation of the gene functions) (HERC2 activating the OCA2 to start pigmentation. Mothers dominant OCA2 gene will cause brown eyes. If the mother carried a broken OCA2 and the child received both broken, it would result in blue eyes)

The genes are recessive, meaning one gene each come from your parents. Because each of your parents have two genes from their parents as well, it means one broken OCA2 gene could be hidden and passed on unknowingly through generations. This is why sometimes brown eyed parents can have blue eyed children. If your parents both have one working and one mutated OCA2 gene, the working one is dominant, but it can be a 25% chance of passing on both mutated genes, resulting in baby blues. 99.9% of all blue eyes are the result of the mutation.

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(Video from the SciSHow hosted by Hank Green) Although blue eyes seem to be a fairly new human trait, everyone usually begins with blue eyes. As an infant, the melanin in your eyes usually is not fully developed and can take anywhere up to one year after birth to reveal its full color. So blue eyes were then thought to be a trait only infants had and it was q uite a shock when the color stuck.

Thankfully, no matter the color and amount of pigment, that will not change the abilities of our eyes or the beauty.

__ Sources: __
 * https://youtu.be/qfSfNIzN7q8
 * http://www.abc.net.au/science/articles/2015/09/04/4294967.htm
 * http://genetics.thetech.org/ask-a-geneticist/origin-blue-eyes
 * http://udel.edu/~mcdonald/mytheyecolor.html
 * https://occupycorporatism.com/blue-eyes-originated-10000-years-ago-in-the-black-sea-region/