Katelyn+N.

=__** WIKI POST #3 **__=

Functions of Neurons:
First off there are sensory neurons, motor neurons, and interneurons. sensory neurons tell the brain what you feel when you touch something. They basically are your touch senses! Most of us think that the majority of our mental life is the nervous system and the brain but there's more, Neurons are just a fragment. DID YOU KNOW THERE ARE AN ESTIMATED AMOUNT OF 100 BILLION NEURONS IN OUR NERVOUS SYSTEM?!? ....holy moly.


 * ~** A typical **neuron** (like in the picture) has all the same parts that any other cell would have (the cell membrane, riboses, etc..) also a few extra specialized structures that are apart from the cell body. The **cell body** is the main part of the neuron, it contains the nucleus which has the chromosomes inside of it. Neurons have a large number of branch looking extensions called **dendrites**. They stick out on the cell body, Dendrites receive chemical messages from other neurons. Below of the cell body we have the **axon**, the main purpose of the axon is to transmit an **electro-chemial signal to other neurons**. In neurons that make up nerves running from the spinal cord to your toes, the axon can be up to 3 feet long!! The axon is covered with **myelin sheath**, which is a fatty cell that is wrapped around the axon many many times. They act like then insulation around an electrical wire. At the very end of the axon are **axon terminals**. The axon terminals are there at the end of the axon to send the electo-chemical signal to other neurons.


 * ~** Between the axon terminals and the dendrite of another neuron is a very small gap called the **synapse** (in the picture above). When the electro-chemical reaches the axon terminals, it causes tiny pieces of the chemical called vesicles to release their contents into the synapes. These chemicals are called **neurotransmitters** which travel across the synapes gap to the next neuron where they find a specific place on the cell membrane called **receptor sites.** When the neurotransmitter reaches the receptor sites its acts as a key to it and unlocks it for **ions** on the outside and on the inside on the next neuron.

==__ Sensory neurons- __ There are sensory neurons in the skin, muscles, joints, and organs that indicate pressure, temperature, and pain. There are more specialized neurons in the nose and tongue that are sensitive to the molecular shapes we perceive as tastes and smells. Neurons in the inner ear are sensitive to vibration, and provide us with information about sound. ==

==__** Motor neurons- **__ able to stimulate muscle cells throughout the body, including the muscles of the heart, diaphragm, intestines, bladder, and glands. ==

==__**Interneurons-**__ the neurons that provide connections between sensory and motor neurons, as well as between themselves. The neurons of the central nervous system, including the brain, are all interneurons. ==



__**video:**__
media type="youtube" key="c5cab4hgmoE" width="560" height="315" I seriously find neurons very interesting!!!

__** Sources: **__

[|https://www.google.ca/search?q=neuron&espv=210&es_sm=93&source=lnms&tbm=isch&sa=X&ei=s2jhUvzVFOeTyQHbyoAg&ved=0CAkQ_AUoAQ&biw=1680&bih=948#q=interneurons&tbm=isch&imgdii=_] (where i got most of my images)

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__** Further readings: **__

[] (very interesting facts about neurons!!)

[] (facts about the brain & neurons)

[] (simplifies what neurons do)

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= MARFAN SYNDROME =
 * WIKI POST #1: GENETICS**

=
Ever wonder why some people have really long limbs and a really short torso or maybe even why theres that one boy or girl at a public swimming pool with an indented chest? well Marfan sydrome could be the cause of that. Marfan syndrome is a genetic disorder that affects the bodies connective tissue which helps hold the bodies cells, organs, and tissue together and also controls how the body grows and develops. There are multiple signs of marfan syndrome but you may not notice them until after in life, This genetic syndrome could lead to death. Studies show that 1 in 5,000 people have marfan syndrome.======

media type="youtube" key="1YNzQXQFO_c" width="560" height="315"

The connective tissue is made up of proteins, The protein that people with Marfan syndrome have is called fibrillin-1. Marfan syndrome is caused by a defect in the gene that tells the body how to make fibrillin-1. The mutation of the body that occurs is caused by a protein called transforming growth factor beta or TGF-B. What causes the connective tissue to decrease is by there being an increase in TGF-B which creates the problems that people with marfan syndrome have .  This picture shows what the transforming growth factor beta (TGF-B) would most likely look like.

__**Most of the signs for Marfan syndrome are easily seen.**__
 * long arms, legs, and fingers
 * tall and thin body
 * curved spine
 * chest sinks in or sticks out
 * abnormal flexible joints
 * flat feet
 * stretch marks on the skin not related to weight gain

Not everyone with Marfan syndrome experience the same thing. Harder to notice signs are heart problems, troubles with <span style="font-family: proxima-nova-n4,proxima-nova,Arial,Helvetica,sans-serif; font-size: 14px; line-height: 1.5;"> the large blood vessel that carries blood away from the heart to the rest of the body. Other signs can include sudden lung collapse and eye problems, including severe nearsightedness, dislocated lens, detached retina, early glaucoma, and early cataracts. Special tests are often needed to detect these signs.

__ **<span style="font-family: proxima-nova-n4,proxima-nova,Arial,Helvetica,sans-serif; font-size: 14px; line-height: 1.5;"> what someone with Marfan syndrome would most likely look like: ** __ <span style="font-family: proxima-nova-n4,proxima-nova,Arial,Helvetica,sans-serif; font-size: 14px; vertical-align: baseline;">

<span style="font-family: proxima-nova-n4,proxima-nova,Arial,Helvetica,sans-serif; font-size: 14px; vertical-align: baseline;">By marfan syndrome being a genetic disorder, it must me passed down through one of the parents by one of them being a carrier of the syndrome in their DNA. This shows there is a 50/50 chance a child could end up with marfan syndrome. <span style="font-family: proxima-nova-n4,proxima-nova,Arial,Helvetica,sans-serif; font-size: 14px; vertical-align: baseline;">

further information
@https://sites.google.com/site/marfansyndrome302/home/10-interesting-facts This site explains 10 different facts about marfan syndrome, their very shocking.

@http://www.medicinenet.com/marfan_syndrome/article.htm This site here is a more advanced version of facts about marfan syndrome.

@https://sites.google.com/site/marfansyndromeseventhgrade/what-is-it Here's a more clear and easily understandable video and description of marfan syndrome.

@http://www.jrmarfan58.com/ A site where a man discrbes how it is to live with marfan syndrome. (click Jon Living with Marfan on the side bar)

** FACT: The first amphibians appeared approximately 370 million years ago during the Devonian Period. **
There has been a lot of research done on the //Tiktaalik// because of its fish and amphibian features. Tiktaalik has a flat head and a neck like tetrapods but fins and scales like a fish. This fish/tetrapod must have been the closest finding with both fish and amphibian features. It had lungs and gills scales, fins, fin skeleton, and ear notches!!



** Further readings: **
[] **Goes into much more detail on how fish evolved into amphibians** [] **Has an interesting image showing the 150 million years of fish evolution**

** resources: **
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