Owl Pellet Lab

Summary:
We started this lab by weighing the owl pellet sample and taking the measurements of the length and width. Then we started to pull apart the pellet and separating the bones from the mass of fur. Once we had the majority of the bones separated, we located the skull in order to identify the type of animal we had.

CER:
From our skull findings, my partner and I concluded that our animal was a vole. The skull length of 20mm and the mandible length of 20mm as well fell perfectly within the range of that of a vole. In addition, the teeth also helped use to identify the animal as a vole.

Similarities and Differences:

Similarities: One similarity between the skeleton of the vole and that of a human is that they have all the same leg bones as a human, fibula, tibia, and femur. Another similarity is that both humans and voles have 24 ribs and 12 pairs of ribs. Lastly, human and vole skeleton's both have distinct vertebrates. 

Differences: One difference between the human skeleton and the vole skeleton is the skull. The skull of the vole appeared to be more pointed while the human skull is a rounded shape. Another difference between the two is the teeth. Voles have large front teeth that point out from their skull, in order for them to be able to dig for food in the ground. The last difference between the two is eye socket location. Since the skull of a vole had a very small width, the location of the eyes is on the sides of the head, while human eyes are placed in the center of the face. 

                                                               

Unit 6 Reflection

What was this unit about?
We began this unit by learning about the brain. In the "Brain Vodcast", we learned about the basic anatomy and physiology of the brain. Specifically, we talked about parts such as the frontal lobe, which is the executive function or the "boss" of the brain, and the occipital lobe, which is responsible for vision. In our first lecture, we talked more about the brain and how it a specialized and adaptable organ. The brain divides the labor as the left side is controlled by the right side of the brain and the right side is controlled by the left. In order to better understand the anatomy and physiology of the brain, we did a brain dissection lab where we were able to dissect and identify the different parts of the brain. http://hayleysanatomyblog.blogspot.com/2017/03/brain-dissection.html
Next, we talked about the different senses we have. We talked about sensation and perception. While the two are related, they are not the same. Sensation is the process by which the brain interprets and organizes the sensory information while perception is the process by which the central nervous system receives input from the environment via sensory neurons. Next, in the lecture, we talked about the receptors that are involved in all the different senses. Thermoreceptors for temperature, photoreceptors for vision, and so on. Finally, we talked about some of the sensory organs and how they function. These included the eyes, ear, nose, and mouth. Additionally, we also did a dissection of a sheep eye to better understand the complicated anatomy and physiology of the eye. I found this dissection, in particular, to be very beneficial in understanding the path of light and all the different structures of the eye. http://hayleysanatomyblog.blogspot.com/2017/03/sheep-eye-dissection-analysis.html The next lecture we had was all about neurons. We discussed the difference between the central and peripheral nervous system. The central nervous system is made up of the brain and the spinal cord and acts as a command center to interpret sensory information, as well as to provide "instructions". The peripheral nervous system, on the other hand, has two parts. The sensory division, which carries nerve impulses from the body to the brain or spinal cord, and the motor division, which carries nerve impulses from the brain or spinal cord to the muscles and glands. We then talked about the different types of neurons, such as the proprioceptors which send messages to your muscles and tendons. Finally, we discussed reflexes and some of the different ones that we have. To see each of our reflexes, we did a lab testing a multitude of different reflexes.
http://hayleysanatomyblog.blogspot.com/2017/03/reflex-lab.html
Finally, we finished off this unit by talking about disorders that can occur in our Central or Peripheral Nervous Systems. One CNS disorder that we talked about was epilepsy, which is a condition of the brain that causes seizures. This disorder can be brought about by a serious infection or stroke, although you can also be born with this disorder as it depends on genetics as well. One PNS disorder that we talked about was shingles. Shingles is often seen in adults who had the chicken pox when they were young as it is a reactivation of the virus. This virus attacks your dematotomes and causes a painful rash.
 

Supplemental Readings
The first reading that we were assigned in the unit was "How to Become a 'Superager'". This reading talked about people older than 65 who were able to remain mentally sharp and were mentally on par with healthy 25 year olds. Essentially, these people were able to become like this due to frequent use of their brain and by working hard at something, whether is was physical or mental. In summary, "All brain tissue gets thinner from disuse. If you don't use it, you lose it". This can be related back to our lectures talking about the brain. It shows how physical and mental exercise is what keeps the anatomy and physiology working right in our brain. The next article that we read was "Fit Body, Fit Brain and Other Fitness Trends". This article was very similar to the superager article in that it stressed the importance of mental and physical exercise and how that all can help the brain to function properly. One quote that really stood out to me from this article was "... the aerobically fit older men's brains used fewer resources during thinking than the brains of out-of-shapte men of the same age, much as a fit body ca use less energy to perform the same physical task as one that is less fit". This reading can be related back to the same idea as the superager article, taking proper care of your brain is key to getting it to function properly. The last reading that we did was on "How We Get Addicted". This article talked all about addiction and how chemically, some people are more likely to become addicted than others. This entire reading can be related back to the last lecture we did on CNS and PNS disorders. At the end of that lecture, we talked all about the addiction cycle and how essentially an addiciton is a disease and should be treated as such.

Strengths and Weaknesses
I believe that this unit had gone very well for me. If I had to choose one strenth from this unit, it would be the eye dissection. Since it was a partner dissection, I was really able to be hands on in the dissection which, although was a little gross at first, helped me to better under the different structures and functions of the eye. One weakness of mine was learning about the different neurons. Upon first watching the vodcast and taking notes, I was slightly confused as their were many concepts to grasp, but after reading over my notes and having an in class disscussion, I was able to better understand what was going on.

An Update on My New Years Goals
It is now the middle of March and believe that I am still working hard towards my New Year's resolutions. I am constantly focusing on living a healthy lifestyle, both mentally and physically. As my time in high school is coming to an end, things have gotten less stressful and I have been able to get more sleep, which is definetly a bonus. Additionally, I do feel like I have been keeping focused on my school work and not slacking off too much, despite the senioritis that I and all my classmates have seem to have been getting.

Reflex Lab

Relate and Review:
In this lab, we tested all our different reflexes. We started with our photo pupillary reflex and tested this by covering our eye for an extended period of time and then revealing it to the light. When we did this the pupil expanded to allow more light to enter the eye. This reflex most likely evolved because early humans used to live in caves and when they had to go outside, they needed to be able to adjust from total darkness to light very quickly in order to be alert in case of danger. Next, we tested our patellar reflex by using a reflex hammer and lightly hitting the person under the knee. Their leg would immediately kick out when this was done correctly. This reflex most likely occurs to help people maintain their balance and catch themselves if they begin to fall. Then, we tested the same reflex, but after the person had done 30 air squats. When we did our experiment, we found that the reflex was more vigorous. We hypothesized that this was most likely because the squats simulated the body being off balance so the reaction was more intense. Next, we tested the plantar reflex by running a pen cap up the care bottom of a foot. When I did this, my partner's toes curled and got closer together. This was a normal response. Lastly, we did an experiment to test our response time. One person stood with their hand out and the other stood next to them and held the ruler above their hand. When the person was not expecting it, the person holding the ruler would drop it and the other person would catch it. Each distance correlated to specific time and we were able to calculate our average reaction time. Then, we did the same experiment, but this time, the person who was supposed to catch the ruler was texting. When we calculated the average time for this experiment, we found that the reaction time was significantly slower.
Claims, Evidence, Reasoning:
I. The reflex tested in part one was the photo pupillary reflex. This is the reflex that allows the pupil to increase or decrease in diameter depending on the amount of light entering the eye at the time. In our experiment, you see clear evidence that this reflex is functioning as we watched the pupil expand as the eye was revealed to light after time in the dark. We believed that this reflex was developed as a way of quickly adapting from dark to light or vice versa.
II. The reflex that we tested in this section of the lab was the patellar reflex. This is the reflex that causes your leg to kick when your knee is hit below the kneecap. My partner and I's patellar reflexes are working well as we both kicked our legs out when we were tapped. We believe that this reflex occurs as a way of keeping oneself balanced or to help us catch ourselves if we begin to fall.
III. The next reflex was the blink reflex. This is reflex is a result of our natural reaction to blink when something gets too close to our eyes. We saw that this reflex is very active as the person blinked almost immediately as the cotton ball was thrown. People have the blink reflex in order to protect their eyes from any debris or objects that get too close.
IV. In this section of the lab, we tested the plantar reflex. The plantar reflex is an important test to determine neurological health. When your toes flex and move close together, that is an indication of a healthy nervous system and is also the typical response for people. But, if your toes spread apart and point upward, that could be an indication of a more serious condition called Babinski's sign. In our experiment, my partner's reflex was perfectly normal as her toes flexed, moved close together, and pointed downward. This all occurred due to the healthy condition of the myelinated fibers.
V. The last reflex that we tested was our reaction time. This specific reflex measures how fast it takes the visual information to travel to your brain and then for your brain to send a motor command to the muscles in your arm and hand to grab the ruler. My experiment showed that every trial, my reflexes improved. However, when I did the same experiment while texting, the results were completely different. It took a much longer time for me to react while texting. This reveals how immense the danger of texting and driving can be. This specific reflex occurs as a prevention method. For example, when you are driving and the car in front of you suddenly breaks, you will break your car in response in order to avoid a car accident.
                                           

Brain Dissection

Questions

1. 

                                      

My personal drawing and picture of our brain, showing the cerebrum, cerebellum, and the brainstem. 

2. Cerebrum: Responsible for sensory and neural functions, also the initiation and coordination of voluntary actions

Cerebellum: Functions to coordinate and regulate the activity of the muscles

Brainstem: Consists of the medulla oblongata, pons, and midbrain. It continues downwards to form the spinal cord

3. The function of the myelin in a neuron is to act as a fatty covering on the dendrites of the neuron in order to speed up processing of the information. It occurs in places such as the eyes, where information needs to be processed quickly.

4. 

                                                 

A drawing of the cross-section and a photo. The pins in the brain represent the thalamus, optic nerve, medulla oblongata, pons, midbrain, corpus callosum, and hypothalamus. 

5. Thalamus (yellow pin): relays sensory info and acts as "center" for pain perception

Optic nerve (white pin): transmits impulse from the retina to the brain

Medulla oblongata (red pin): the lowest part of the brainstem, it contains the control center for the heart and lungs

Pons (blue pin): the area of the brainstem that connects the medulla oblongata and the thalamus

Midbrain (black pin): a part of the central nervous system that is associated with vision, hearing, and motor control

Corpus callosum (green): allows for communication between the two hemispheres of the brain

Hypothalamus (white pin): regulates the nervous system and connects it to the endocrine system via the pituitary gland

6.

                                       

A sketch and a photo to show the difference between white and gray matter. 

Relate and Review 

We started this lab my examining the outside of the brain. We located the meninges, the shiny covering on the outside of the brain. Next, we identified the cerebrum, cerebellum, and brainstem (as seen in pictures above). Then, we cut the brain in half longitudinally. From there we were able to locate the thalamus, optic nerve, medulla oblongata, pons, midbrain, corpus callosum, and the hypothalamus. Lastly, we made a cross sectional cut of the cerebrum and identified the gray matter and white matter. This related to what we have done so far as it helped to give us an actual visual of the parts of the brain we are learning about. It also helped us to see how all of the parts of the brain are connected and reinforced our understanding about each of the part's functions. 

Sheep Eye Dissection Analysis

In this lab, my partner and I dissected a sheep eye and were able to identify all internal and external structures of the eye. On the outside, we were able to identify the cornea, which appeared cloudy and is the first structure that light passes through. It is also the protective layer of the eye. We also identified the sclera, the very hard exterior of the eye, this is also the white of the eye. Next, we located the optic nerve, which is the second to last step in the path of light as it sends the information to the brain and the brain is able to process it into vision. Then we found the external eye muscle that allows our eye to move up, down, left, and right. Finally, we identified the fatty tissue. This was white and yellow in color and gives the eye cushioning.

For the second part of the lab, we cut into the eye to identify the interior anatomy of the eye. Cutting through the sclera was difficult, as it was quite tough. When we finally cut all around the eye, we identified the vitreous humor that resembled a jelly like substance. There is also the aqueous humor, which is located behind the cornea. Both the vitreous humor and aqueous humor help to maintain the shape of the eye. When we removed the retina, it revealed the choroid layer which was a thin black layer found in-between the sclera and the retina. In one place, the retina is firmly attached to the choroid. This part is known as the blind spot. Next, we removed the choroid which revealed the tapetum lucidum, that helps animals with their night vision as it functions to reflect light onto the retina.

Finally, we removed the vitreous humor and the lens to reveal the ciliary body. The ciliary body appears ridged. We then identified the lens. When the lens appears cloudy, that means it has a condition called a cataract. A cataract prevents or reduces the amount of light that reaches the retina. Then, we identified the pupil which is the opening in the center of the iris. Pupil size increases with decreased light intensity and decreases with increased light intensity. Lastly, we removed the cornea from the front of the eye and made small cuts in it. We noted that it was very thick, mostly likely to act as protection for the eye.