Sheep's Eye Dissection

In this lab, we got to dissect a sheep's eye in order to examine its anatomy and physiology. One major difference I noticed as our group started opening up the eye was that the iris was oval-shaped and the pupil was lying on its side horizontally, while human eyes have round iris's and round pupils.

On the outside of the eye, extrinsic muscle bundles are found side by side with yellowish fat which helps protect the eye. The cornea is the cloudy, black-looking centerpiece of the eye, though it's clear and cloudy (not black) outside of the picture. Inside the eye, the eye's anatomy is arranged so that the cornea is the first thing that light hits as it enters the eye. Next, it is the pupil which is in the middle of the iris, then the lens is behind the pupil while the sclera surrounds the rest of the eye. The vitreous humor fills the inside of the eye so that everything is held in place. The retina is the yellow film-like layer (shown in the third picture below) that's located at the back of the eye. Behind this object, in order, there's the tapetum lucid, the choroid coat, and the optic nerve.

The physiology of the eye eye allows us to have our sense of vision, and our perception of light and dark. The cornea helps protect the eye from things such as dirt which is why it is located at the front of the eye instead of inside it or at the back of it. Behind the cornea, the pupil is the one opening in the eye which allows light to enter this item, and the lens behind the pupil helps bend the light to focus on objects that we can see. The Ciliary body holds the lens in place and the suspensory ligaments adjust it's size and therefore, focus. In between the lens and the retina is the vitreous humor which provides nutrients for the inside of the eye and maintains the eye's pressure. The images from the lens are then projected onto the retina, which converts them into signals that it sends to the brain via the optic nerve. The dark choroid coat behind the retina helps with this process by absorbing light so that it will not scatter around the eye.



(outside look at the sheep's eye)


Inside of the eye left, and the back of the
inside of the eye right showing the retina
on top, then the tapetum lucid, the choroid
coat, and behind that, the optic nerve.


(image of the lens, small white circle, and
the choroid coat (black) inside the eye)


(assembly of all the dissected parts of the eye,
excluding the fat)

Microbeads and the Great Pacific Garbage Patch

In the past couple of weeks I have been concentrating my research on the main products causing plastic pollution and solutions to fix them. In particular I was struck when I realized that the Great Pacific Garbage Patch was really a big swamp-like area of floating garbage instead of a solid land mass of trash as many people are led to believe. The main problem with plastic, as I mentioned before, is that as it photodegrades in the ocean, it only breaks down into smaller and smaller pieces leading to millions of tiny plastic particles floating around instead of one digger piece of plastic. These tiny particles of plastic can be found outnumbering zooplankton 6:1 in some parts of the Pacific Ocean around the Garbage Patch. Furthermore, more tiny particles of plastic called microbes, can be found pre-made in girls beauty products such as face wash. Once microbeads end up in the ocean they are eaten first by zooplankton and small fish due to their resemblance to fish eggs. As smaller fish are continuously eaten by larger fish, the plastic and toxins in the microbeads continue to bioaccumulate instead of disappearing. They can affect the entire food chain- including us when we eat seafood. Fortunately, President Barack Obama signed the Microbead Free Waters Act of 2015 to phase out the production of microbeads in beauty products by 2020.

In order to learn about the other items that were poluting our oceans and our beaches, I volunteered in a beach cleanup over the weekend to help the community. When I reached the beach, I was pleasantly surprised to note that there was an abundance of trash and recycling cans dotting the beach so that people had the opportunity to get rid of their waste in a sustainable and non-polluting way. While I did find some trash buried in the sand, overall, there was much less garbage than I expected.

I also took a trip down to the Monterey Bay Aquarium over the weekend in order to earn more about sustainable methods that help save energy and marine life along the coast. Examples of coastal life shown below.









As I walked through the exhibits, I realized that they had a section on plastic and the North Pacific Gyre.




(Plastic taken from the Gyre)

What I took from the exhibit was while plastic could be deadly and very harmful to marine life, it could also be very beautiful as well. If people take the time to recycle plastic, they can turn it into art like the jellyfish made out of bottles below.





Through this process so far I've learned to see the silver lining in every cloud because if society allows us to only focus on the cloud and the negatives, then we'll never be looking for the solutions. My greatest setback is time right now as I am putting together my final project. My research is as complete as it can be at this point and I just need to put it all together.

The Clay Brain

In this activity, our team assembled a brain out of different colors of play dough in order to illustrate the different parts of the brain. In our models, we tried to show not only the lobes, but the different glands, gyrus's, and sulcus's as well. For example, the lateral cerebral sulcus is located in between the frontal and temporal lobes, and the pineal gland (shown in pink in the first picture) is located in between the cerebellum, brainstem, thalamus, and cerebrum. The different parts of the brain are labeled on the cardboard next to their corresponding structure.



Left Hemisphere of the brain (view
along the Sagittal plane)


Right Cerebral Hemisphere (lateral
view)

Living Without Pieces of our Brain

A woman who had been having trouble with speech and balance throughout her life was discovered to be missing a cerebellum in her brain. So far only 9 people have been able to live without a cerebellum as most people without this part of the brain die in childhood. This woman discovered that she was missing a cerebellum at age 24. 

The cerebellum is an important part of our brain located underneath the right and left hemisphere. It contains about 50% of the brain's neurons even though it only makes up about 10% of the brain's total volume. The cerebellum is also in charge of controlling voluntary movements, balance, and is involved in speech. According to researchers, it appears that the woman's brain has worked to compensate for her missing cerebellum and she is experiencing less movement and speech impairment than they expected.

If the parietal lobe was missing in a person's brain the same way that the cerebellum in missing in this woman's brain, then that person would have trouble processing pressure, visualizing spaces, and understanding the spoken word. The right side of the parietal lobe integrates sensory information such as touch (mainly processed in the somatosensory cortex part of the lobe), spatial sense and navigation. A person may have trouble finding their way around, even in places that are familiar to them. They may also have trouble feeling temperature and pressure so it is important for people with damaged or missing parietal lobes to stay away from hot stoves since they may be damaging themselves without even knowing it. Several parts of the parietal lobe process language, so a person missing a parietal lobe may have trouble understanding what they and other people are saying. Other parts of the brain could take over the spacial sense, language, and feeling pressure, but while missing the parietal lobe a person will most likely to have a varying amounts of disabilities in these areas.