Owl Pellet Lab

procedure 

We began out dissection by getting the owl pellet to our table. We opened the tin foil and began picking away at the brown mess. We began removing all the brown fur trying to find some bones. The first thing we found was actually the lower jaw of our organism. We carefully removed more brown fur from the pile and cleaned out to brown fur from the bones we found. It was really difficult to clean up some bones like the skull since they had many holes and caves that required us to be very delicate. At the end, we made a pile of all the bones we found and left a pile of the shredded owl pellet.


organism

After we collected all the bones from the owl pellet, we had to identify what organism the skull we found belonged to. We started off measuring the skull that was less damaged and came to the measurements of a length of 17 millimeters and a width of 13 millimeters. Looking at the Owl Pellet Dissection Guidebook, our measurement identified the organism to be a mouse. According to the guidebook, a mouse skull is less than 25 millimeters and the mandible is 9-16 millimeters which fits our measurements. Also observing the comparisons of the skull of a mouse, shrew, vole, rat, and pocket gopher, the mouse skull in the guidebook was the most like our skull from the owl pellet. The skull in the guidebook had two hooks coming from the side of the face and a long hole through the front top part of the face.

comparison

Similarities: One of the things that I found similar between the mouse skeleton and a human was they have similar femurs. Both femurs and the large relative to their body size. Another thing I found similar between the mouse and human skeletons are the vertebrae. Both vertebrates have the cervical vertebrae that's smaller and in the neck, the thoracic vertebrae that's in the bulk of the back, and the lumbar vertebrae that's in the lower back. The structure of the mouse phalanges also struck me to be pretty similar in the struct of our phalanges.

Differences: One big obvious difference between the mouse and human skeletons are the skulls. The mouse skull differs greatly in proportional size and small details in the structure of the skull. Another difference I noticed was that the human pelvis was different from the mouse pelvis. The mouse pelvis was a simple long bone hole at one end. The human pelvis is a much larger flatter bone and has more ridges and indents for more muscle. One final difference was the scapula. The mouse scapula was a lot larger in size and proportion to its body than the human scapula. The mouse scapula was also shaped in much more of a large long bone compared to the human scapula that was shaped in more of a flat bone.

Reflex Lab

Analysis

In this lab, we went over some of the body's natural reflexes to environmental stimuli. The first lab reflex we went over was the photopupillary reflex. We had one partner close their eyes for about a minute, then when they open their eyes, the other person quickly shines a flashlight in their eye. What happens is that pupil contracts to decrease the amount of light getting into the eye.

The second lab is the knee jerk reflex or the Patellar Reflex. One student sat with one leg dangling, and the other student hits the leg just below the knee with a reflex hammer. The leg that was hit with the hammer immediately kicks up. This reflex could have been developed after more medicine and doctor exams were taking place in human society for an easy way for doctors to check if environmental stimuli and reflexes were properly working.

In the Blink reflex, one student held up a see-through plastic wrap in front of their face while the other student threw a cotton ball at the person. The person would blink anytime the brain sees something is coming toward the face in fear that something would hit the eye or get into the eye and damaging it since it's very fragile.

In the Plantar Reflex, one student drags the cap of a pen firmly on their foot from the heel to the base of the big toe. The student who receives the dragging should clench and flex their toes, moving them closer together.

Our last lab is the Reaction Time Reflex. One student puts his hand at the bottom of the ruler and the other student that's holding the ruler up will randomly drop the ruler. The person that's not holding the ruler tries to catch the ruler as quickly as possible. Wherever they catch it, convert the inches or centimeters to time. Afterward, we repeat the same experiment, but now, the person catching the ruler is also texting. This was to simulate texting and driving and how texting slows our reflexes and reactions of important actions. The times were again recorded for the second part of the lab.
When I participated in the second part of the lab, my reaction time actually got faster by an average of 0.02 seconds when I was texting. This unusual occurrence likely could've happened, because the I wasn't very distracted by texting and I got better at catching the ruler as I got more and more practice.

20 Time Second Blog Post

Sweden Wannabe

What have you learned about your topic so far?

For my topic, I've learned that Sweden has a great program on how they are able to recycle a lot of their waste. They are able to convert 99% of their wastes into reusable energy. Sweden's success in recycling their wastes comes from 2 reasons. The first reason Sweden is able to so successfully recycle their waste is due to their citizens. The citizens of Sweden play a large role by disposing their trash in an organized manner. Sweden's citizens separate their wastes into metals, plastics, compost, and other materials. This way, it is much easier for the WTE plants to organize the waste into its proper method of recycling. The WTE plants, or waste-to-energy plants, are the second reason behind Sweden's success in recycling. These giant plants burn some of its wastes and convert it into usable energy that is able to provide heat to 810,000 households. 

What have you learned about yourself?

I found myself being very interested in recycling and our efforts in it. I discovered that recycling can have a massive positive impact on our environment and it is very easy for our citizens to follow through with. However, despite the effortlessness of recycling, many people end up not recycling mostly because they don't know how to. They don't know what materials should be thrown where, and it has made my passionate about giving society a little help in educating the public and provide more a wider diversity of trash cans to encourage and increase recycling. 

Have you had any setbacks? How do you plan to handle them, or how did you already handle them?

One of the things that I have learned that set me back was that Sweden's waste to energy system has its fair share of criticism around the world. Other people also say that Sweden doesn't actually recycle 99% of their waste because the term "recycle" means to reuse whereas they alter the purpose of some materials. Others are concerned about the plants ejecting an immense amount of carbon dioxide into the atmosphere. 
A setback closer to my goal is that it is very expensive to build a waste-to-energy plant and I should just focus on increasing recycling. 

What are the next steps in your process?

My next steps are as following Sweden's lead, to set up more trash cans in different areas, and also to increase the variety of what trash is disposable. I hope to talk to city and ask to set up more trash cans and recycling bins around residential areas where the number of trashcans seems lackluster. I hope to put more trash cans and recycling bins next to crosswalks. 

How can you apply anything you have learned to yourself, your school, your community, etc.? 

Throughout learning about this project and discovering new interests about me, some ways I can apply what I have learned to my school and community by picking up trash that didn't make it to the garbage can. I can also help my school and community by properly disposing wastes into the garbage cans and recyclable material into the recycling bins. Organizing waste and properly disposing them to where they should go makes a big impact on how much less waste ends up in landfills. 

Brain Dissection Analysis

Relate and Review

After scooping out the brain of a bucket, I carried the specimen from to our lab table. From the outside, I was able to see the cerebrum, the cerebellum, and the brainstem from the outside. The brain, especially the cerebrum, was covered in an oily sheen. My lab group places pins on the anterior, the cerebrum, the posterior, the cerebellum and the brain stem, and drew the sketch from my perspective.

In the picture below, the there is a perspective of the brain from my partner's view. It has a white pin to mark the anterior side of the brain, a yellow pin to mark the cerebrum, a black pin for the posterior, blue for the cerebellum, and a red pin for the brainstem. It was really easy to differentiate between the cerebrum, the cerebellum, and the brainstem since they all have specific obvious locations and look pretty different from each other.

After observing the outside of the brain, cut the brain along the middle of the brain, splitting it into left and rights sides. We noticed that from the inside of the brain, the cerebrum or outer section of the brain looked gray. The center part of the brain, the thalamus and corpus callosum for examples, was a white color. The outside was known as gray matter and the inner section was white matter. We found the medulla oblongata, the pons, the midbrain, and the corpus callosum, but our table had some trouble identifying where the thalamus and hypothalamus was. We originally thought the hypothalamus was where the thalamus was, and the thalamus was where another part of the corpus callosum was. But with help from Dr. Orre, we were able to locate the thalamus and hypothalamus safely and soundly. We marked the above sections of the brain with the pins, took the picture, and made our detailed artistic sketches.

This picture shows the inside of a halfway cut cerebrum. The red pin (upper) represents the medulla oblongata, the blue pin (right) marks the pons, the blue pin (left) marks the midbrain, the black for the hypothalamus, the yellow for the thalamus, the red pin (lower) represents the corpus callosum, and the green for the optic nerve. It was pretty hard to distinguish the different sections of the brain since everything is pretty much the same color. But with lines and shadows between the sections, we were able to identify most of the parts before help.

After making our sketches of the inner view of the brain, we cut a half of the cerebrum in half hotdog style. This way, we were easily able to identify the gray matter between the white matter and see another view of inside the cerebrum.

This picture shows the inside of half of the cerebrum cut hamburger style. The white matter looked like a tree branching into the section of the gray matter.

After finishing the lab, disposing the specimen, throwing away garbage, and cleaning the table. We got down to the questions from the lab. The questions along with the table and functions are in the pictures below.

Sheep Eye Dissection Analysis

The Anatomy and Physiology of the Eye

The function of the eye is to observe our surrounding by taking in and transforming light into electric signals which can be decoded into images and interpreted by the brain.

The eye is surrounded in a tough covering called the sclera, also known as "the white of the eye". The sclera protects the eye and is transparent to allow light to pass through it. Humans have 6 extrinsic muscles around the eye to move the eye by some of the muscles contracting and other expanding. The eye is surrounded in fatty tissue to cushion the protect the eye from impact or damage.

Light first enters the eye through the cornea, a transparent cover that protects the pupil, the iris, and the anterior chamber. The aqueous is found behind the cornea and helps give the eye its spherical shape. The cornea roughly focuses the light, and then the light enters through the pupil, which is a dark circle in the center of the eye that allows light to pass through. The pupil is not technically a structure but instead is a hole to allow light into the eye. Surrounding the pupil is the iris, the colorful part of the eye. The 2 muscle layers of the iris constrict and expand to change the size of the pupil to control the amount of light entering the eye. Staying in a dark room causes the iris to constrict enlarging the pupil to allow more light in. But if you walk outside into the sunlight, the iris will quickly expand shrinking the pupil to prevent too much light entering the eye and damaging it.

After passing the pupil, the lens focuses the light by bending and altering the shape and angles of light rays to focus them properly. A condition where the lens turns cloudy is called cataract. Cataracts reduce the amount of light reaching the retina, but can be treated by removing the lens and replacing it with an artificial one. The lens is held in place by the suspensory ligaments that join with the smooth muscle containing ciliary body. The light passes through the vitreous humor that fills the center cavity of the eye which also helps the eye keep its shape as does the aqueous humor. Glaucoma is the condition where there is too much fluid pressure from the aqueous and vitreous humor in the eye, causing eye damage. The retina lines the back of the eye. The retina lies on top of the choroid layer, which is a network of blood that is used to bring oxygen and nourishments to the back of the eye. The tapetum lucidum is not found in the human eye but it helps animals in night vision since it can reflect light at very low intensity onto the retina. The retina is lined with photoreceptors that sense different types of wavelengths of light that is converted into electric signals and sent through the optic nerve to the brain.

Other dysfunctions of the eye are myopia (nearsightedness) or hyperopia (farsightedness). In myopia, the eyeballs are too long and the cornea is too curved; the image lands in front of the retina and allows the person to see near images but not far ones. In hyperopia, the opposite occurs. The eyeballs are too short and the cornea is not curved enough. The image lands behind the retina and the person won't be able to see things clearly when they are close, but can see objects clearly when they are further away.