Amazing revelations from study

The first one is from neuro, take this test out.

http://blindspottest.com/

I know the blind spot is a very common and well known optical illusion but the brain's power to compensate astounds me. The brain's cortical areas just fill in the gaps with the external environment. Then again, it should also be noted that the eye is always in motion. These movements help to fill in the spots you don't see on either eye as well by creating a sort of residual imprint in your brain. The vision is very complicated, processing starts through parallel processing through the optic nerve located right behind your eyes, and continually gets processed up till the point in the brain that makes sense of everything you see. The arrangements of the brain and how it processes images is absolutely fascinating but I will not go into that at this point.

The second thing that was fascinating was how we localise sound in 3D space. It was my little pet project this semester but I'll go into that closer to my neuro exam when I need to summarise things.

The last thing I'll talk about is aging and cancer. There's a genetic theory floating around that aging and cancer are two competitive processes. You see, you have DNA in all your cells, except your red blood cells of course. You also know that your body is constantly replenishing lost cells that may have occurred through physiological cell or just because the cell is damaged in some way. Whenever this happens, DNA replication occurs to give another copy to the new daughter cells. DNA is arranged in two strands, in the double-helical structure we are all familiar with.

This DNA is replicated on both strands, in a 5' to 3' manner, but for the opposite strand which is in 3' to 5', replication is broken up in little 5' to 3' fragments. The problem with this is that the end of the 3' to 5' strand cannot be replicated. The way it has dealt with this is a non-coding repetitive region called the telomerase which gets shorter every time replication occurs. Now, there are enzymes that can sustain the telomerase but then that leads us to two problems.

First problem is, when there is a mutation in this enzyme, the cell may be able to escape cell senescence. Senescence is like, the cell's life cycle, escaping from this life cycle leads to immortalisation. The cell can divide as many times as it likes, in whatever rate it feels like. This is the pathway to cancer. If cells can't divide as many times, it has a certain limit to the amount it can divide, eventually the telomerase enzyme isn't sufficient to replicate the DNA to the point that it division causes a breakdown of the coding region of the DNA. This leads to aging.

I don't know if people without a biological background were able to understand that, but I found it absolutely fascinating. Anyway, back to studying.