Sheep Eye Dissection Analysis

In this lab we dissected a sheep's eye. A sheep's eye is very similar to our own, except they need to see in low light environments, meaning that they have a tapetum lucidum on the choroid coat that allows light to reflect more onto the retina. 

Eye before the dissection 

The cloudy part seen here is the cornea. While the animal is living, the cornea is not cloudy and is only cloudy now because of the non living tissue. Compared to the sclera, the cornea is relatively thin but serves to protect the eye from debris.

Eye after all the extrinsic muscle and fatty tissue is removed

The schelera of the eye is shown above, the white part of the eye. The sclera is tough, and helps protect the eye and inside because of its toughness. The extrinsic muscles and fatty tissue attach the to sclera of the eye as well. The muscles help facilitate eye movement, and can move the eye depending on which muscles are pulled. The fatty tissue serves as a cushion for the eye and ensures that it fits snugly in the eye socket. The fatty tissue is more yellow that then the brown muscles.

Choroid coat and tapetum lucidum 

The choroid is used to nourish the back of the eye, and has several blood vessels running to and through it. The tapetum lucidum is used to reflect light onto the retina and is part of the choroid layer ( the shiny blue seen above). It is used in mostly nocturnal animals or animals that need to see in low light conditions. When we take a flash picture of an animal at night, the reason that its eyes glow is because of the tapetum lucidum and the light being reflected back. Humans don't have this structure since we aren't nocturnal and have no need to see in low light conditions to survive. The retina contains the photoreceptors for our vision and allows us to see. These signals are transmitted through the optic nerve to the brain where they are interpreted. Because of the way that the optic nerve is connected, humans have a blind spot at that point. However, this spot is barely noticeable because of the way that our right and left eyes work together to create a complete image of whatever we see.

Photo of the Lens

The lens is the structure of the eye that changes shape to focus light on the retina. It is relatively hard to compress, but is still rather squishy. Ciliary bodies and sensory ligaments surrounding the lens help shape it and focus light on the back of the retina. The lens can also become damaged or cloudy and impair the animal's vision. A cataract, for example, is a cloudy lens which prevents or reduces the amount of light that can reach the retina. Another way the eye can be damaged is glaucoma, a condition where the fluid pressure of the eye is too high and causes eye damage.

Lens, vitreous and aqueous humors removed so pupil is visible

The pupil is the opening in the iris through which light passes. The sheep's pupil is rectangular (see above) while a human's is circular.

Labeling of all the parts!

20 TIME - What's Next?

For my next coloring book page I was thinking of doing something that would follow the lines of what a traditional coloring book has so I could have a new and trusted way of trying out some new patterns. I'm not sure how to go about it; I talked to some people on what they looked for on a coloring page and I got very different responses. Some said that they preferred detailed pages so they could create more intricate patterns. Others said they liked large patterns where they wouldn't have to change color pencils often and they can make broad strokes.
I haven't had a chance to draw the pattern yet, but I found some patterns/videos that seem to be really interesting and cool to do.

https://www.youtube.com/watch?v=Nw9z6fXpuFk

I wouldn't do something this large, but it's interesting to see how he was able to incorporate so many different patterns into a single mandala.

The Clay Brain

In this lab, we reinforced the different sections of the brain by creating a clay model. We used different colors to show different areas of the brain in both the left and right hemisphere. It really helped show the different areas of the brain and how specialized each section is and how they're different enough to be classified as different structures inside of the brain. 

Missing Pieces

This article talks about the adaptability of the brain. One woman was discovered to be missing her entire cerebellum, the part of the brain that represents only 10% of the brain's volume but 50% of its neurons. Located below the two hemispheres, the cerebellum main job is to control voluntary movements and balance, and helps in our learning of those as well. When looking at the woman’s history, it’s clear that she has the signs of missing her cerebellum; she started walking until she was 7 and had trouble communicating clearly until she was 6. However, the fact that she can communicate at all demonstrates the great adaptability of the brain to compensate for missing pieces and how even people who are missing parts of their brain can still live a relatively normal life.

What if...?
You were missing the "pons" part of your brain. The pons contains nuclei that relay signals from the forebrain to the cerebellum. It also works with sleep, respiration, swallowing, bladder control, hearing, taste and other functions. Without the pons, it would be unlikely that the brain could function properly because of the lack of a signal relay to pass along the messages from one area of the brain to another. One disease associated with the pons area is central pontine myelinolysis (CPM) that causes damage to the myelin sheaths of the neurons of the pons. It can cause acute paralysis, difficulty swallowing, balancing, walking, and other activities that many of us take for granted. If left undiagnosed, it can lead to "locked-in" syndrome, where the patient is aware but cannot move or communicate because of paralysis of all voluntary muscles except the eyes. These diseases/dysfunctions help show the importance of the pons and its necessity in the brain. 

"Mirroring People" - Marco Iacoboni : Power Hour Reading

For my power hour reading, I chose Mirroring People, by Marco Iacoboni. The chapter I read is called "Monkey See, Monkey Do" and deals with the mirroring neurons in the brain and how our actions and other people's actions are perceived. When we see someone picking up an object - for example a tennis ball - our own neurons fire in response to that to mirror that action, even though we are not performing that action ourselves. This response differs from species to species, in macaque monkeys, these neurons don't fire when a pantomime of an action is being performed, but in humans they do. This is likely because monkeys don't pantomime actions to teach them, but in humans, imitation is key.
One of the experiments mentioned in the book had to do with a 41 minute old baby. Every second of the baby's life was documented to ensure that it had never seen the actions before. A researcher then performed specific actions to the newborn, and the newborn imitated them perfectly even though it had never seen them before. This suggested that newborns don't learn to imitate, they actually learn by imitating, disproving old theories about human imitation and learning. In fact, it's been shown that babies LOVE imitation games. Imitating a baby's movements automatically make you that baby's favorite, and the same is true for all humans of all ages as well. Having someone imitate you in a casual conversation also helps you connect with the other person better, and helps facilitate a better short-term relationship.
The reading seems to be really credible, it specifies many experiments around the globe, and takes into account all of the respective scientists's personal stories and how it could have affected their thought process and methods. The author comments on other experiments and either agrees with their results or hypothesizes a new experiment to test the results further and maybe get different ones. It was nice how he decided to do that since it showed that he was really engaging with the experiments instead of parroting someone else's work.

Coloring Book Page - Almost There

This week I tried to stick with a single pattern when creating my coloring book page. I decided to make it in the outline of the SHS Falcon because I wanted to create something that was a little bit closer to my home and community. I still have to decide how I want the pattern to look like, I tried doing some smaller scale ones on scratch paper but it ended up looking too cluttered. The first pattern I tried was a wave pattern, but it's really easy to mess up the pattern by accidentally shifting it over a little bit, so I decided not to try that one on a larger scale. A pattern that I did really like was this circular pattern that I had seen from a youtube video, and it didn't look too cluttered when I did in on a small scale, but when I made it bigger on the 18x24 paper it looked really messy, so I threw it out and started over.

Because of the series of mistakes and trial and error fails that I did while trying to get the correct design, I didn't get a chance to complete a final coloring page - but I have one thats halfway there right now so hopefully by this weekend I'll be able to update this post with pictures of the completed page :)


UPDATE:
Here's the second coloring book page:

Unit 7 Reflection

In this unit we learned about the different parts of the muscular system and how they worked together to allow the body to move and function. We learned about the different movements of synovial joints, and in order to understand the movements and functions better we created dances to go along with them, using the vocab words like supination, pronation, rotation, and circumduction. It was fun and challenging to try and imitate popular dances like the "macarena" using only anatomy terms.

We got to further explore the different muscle groups in a chicken dissection where we labeled all of the major muscles. The chicken dissection and of the major labeled muscles can be seen at this blog post. Here's a photo that didn't make it onto the blog post, it was interesting and weird to see how there was a hole in the bottom of the chicken where all of the "giblets" were stored.

Next we got into the more molecular based part of how the muscles move, and learned about the different types of fibers that make up our muscles like actin and myosin, and how the two work to make our muscles contract and elongate. The process itself is composed of a variety of steps, and to help us understand the process better, we created a stop-motion muscle contraction video. 

From there, we learned about the individual muscles themselves and the groups that they were a part of, as well as the types of motions that they facilitated and the location of each muscle group. One of the ways that I was able to learn all of the different types of muscles was by creating a concept map that listed the location and motion of each major muscle.

One thing that I would want to learn more about is the structural differences (if any) between voluntary and involuntary muscle groups, and the diseases that affect muscles. Many problems arise because of muscle atrophy, and it would be interesting to see how the atrophy first began and what was causing it. 

As the year starts to come to a close, and finals and AP tests are seen right around the corner, it often feels like I'm sacrificing sleep to keep up with the workload rather than maintaining a balance between the two. I've started to figure out new ways to study so that I'm studying smarter instead of harder, and so far it seems to be working, so hopefully I'll be able to make up for lost hours of sleep. It's at this time that I'm really happy that I chose classes that I'm interested in, like this class and AP Bio, because the homework and studying doesn't really feel like work, it feels more like a project where I get to deepen my knowledge in topics that I already wanted to learn about.