Unit 7 Reflection

For this unit, we focused mainly on the skeletal system, and more specifically, what the bones in our body do, how they work, and what certain ones look like. As with many other units that we have learned in Anatomy and Physiology thus far, the purpose of this unit was been to correlate the functions and dysfunctions of the bones in our system in order to understand how they help our body work the most efficiently and healthily as possible. Essential understandings include the classification of bones, the gross and microscopic anatomy of bones, the function and dysfunctions of the skeletal system, how lifestyle choices affect bone health, the relationship between the structure and function of bones, tissues, and cells, and how the skeletal system works to help maintain homeostasis.

First off, we went over the general functions and dysfunctions of the skeletal system. Bones are divided into being either axial(integral to framing the body) or appendicular(on the appendages of the body), and mainly work to support the body, protect soft organs, move in accordance to skeletal muscles, store minerals, and form blood cells. Bones are also responsible for constantly regenerating and discarding bone tissue throughout one's lifetime, in a process called bone remodeling, which we would cover more in depth later on. When one of these functions of the body are compromised, it is often due to a certain disorder associated to the dysfunction of the skeletal system; for example, osteoporosis, which is more common amongst women, causes bones to lose the stored minerals that they have and create brittle bones the to break more easily and often create mini-fractures that compress the appearance of the skeleton. Other disorders include scoliosis, which is when the structure of the spine is irregularly curved(a dysfunction in supporting the body) and arthritis, which is the inflammation of joints(inhibiting the function of movement).

Carter, Henry Vandyke, and Henry Gray. Osteoblasts and osteoclasts on
trabecula of lower jaw of calf embryo. Digital image. Wikimedia Commons. N.p.,
16 May 2006. Web. 17 Apr. 2017.

Next, we went over the biological composition of bones, and their purpose in bone density. Bone remodeling, as mentioned before, is a process that all bones in the body undergo, and osteocytes, osteoblasts, and osteoclasts assist in, and each type of bones cell has its own role. Osteocytes can be considered the older generation of osteoblasts and osteoclasts(those young 'uns), as they are firmly embedded firmly in the bone itself and send signals for the other two types of cells to do their jobs. Osteoclasts are the bone destroying cells(much like the angry teenager stereotype) that get rid of bone tissue to maintain and repair injured bone. Osteoblasts, on the other hand, "blast" new bone material on the bone in order to replace that injured bone. Alongside cells, there are also a few notable
hormones and minerals involved with bone remodeling as well, which helps emphasize why a healthy diet is important for all the systems of the body. The parathyroid hormone(PTH) is secreted when the osteoclasts are more active and there are lower Ca2+ ions in the blood in order to indue those ions and phosphate from the bone into the blood, and calcitonin is used to bring Ca2+ ions back into bones and at a normal level(as well as keep osteoclasts in check). Proper nutrition is thus extremely important in bone remodeling, because the vitamin D(which helps absorb calcium into the body), vitamin K(assorted vitamins that go straight to the bone), and vitamin C(which helps produce collagen secreted by osteoblasts) that we ingest all are necessary to feed the process of bone remodeling.

We then went more into specifics on how the body repairs bone fractures(serious ones that cannot get fixed only through bone remodeling). Primarily, one must know the difference between certain types of fractures of bone, which include complete/incomplete(whether or not it breaks straight through the bone)or closed/compound(whether or not the skin is pierced by the bone). Other types of fractures are a comminuted fracture(broken into 3+pieces)and an oblique fracture(where the break occurs at an angle)but regardless of the type of break, all bones are repaired (once the ends of the bone meet) through the creation of a blood clot that turns into a procallus(mass of protein fibers). Fibroblasts then arrive at the scene to establish connections of dense connective tissue, followed by chondroblasts and osteoblasts, until finally time becomes the final instigator in creating cartilage and bone into a bone mass called osseous callous.

Villarreal, Mariana Ruiz. Human skeleton.
Digital image. Wikipedia. N.p.,
 3 Jan. 2007. Web. 17 Apr. 2017

General anatomy paired with a little bit of physiology was learnt in the last few lessons on the skeletal system, about both joints and the bones of our body. Joints work mainly due to their creation of either a first, second, or third class lever that help us move our bodies with ease, and are classified base on functional and structural qualities. On the functional side, synarthrosis names immovable joints, amphiarthroses contains slightly movable joints, and the group diarthroses has freely movable joints.  Structurally, joints are divided into fibrous(ligament joining), cartilaginous(cartilage joining) and synovial(without anything in between). Add the two classifications together, and specific joints within the body come to mind, like the synovial diarthrotic joint of our wrist, elbow, hip, and shoulder. With the mentioning of specific joints within the body, it is impossible not to mention the individual bones of the body that are the most important in supporting and transporting ourselves. In a bone lab that we conducted in class, we were assigned to learning about and memorizing a choice number of bones
, a notable few including the femur(the largest bone in the body), the mandible(lower jaw), and the false and floating ribs under the 7 true ribs that are not fully connected to the rest of the ribcage.

After learning all about the skeletal system, there is still some areas that I have questions on, including whether flexibility has anything to do with bones, why being double jointed is a thing, and why creaky joints/old injuries are sometimes affected by the weather(or so say old people).

As a student during this unit, I felt that I did keep up with paying attention in class and properly absorbing the material that we learned in class and at home by keeping up with homework and class work. The only lab that I posted during this unit, the Owl Pellet Lab, was truly quite fascinating to me (while I did do a similar lab in 4th grade, the specimens were rather skimpy in bones and not nearly as big as the ones we had this semester), and I felt that I was able to work well with my partner in order to figure out what kind of animal we had. Participation in class was, I think, rather normal for me, and if there is anything that I felt this unit I could have improved one, it might have been starting to study for the test a bit sooner and keeping a steady progress on the 20 Time Project. From my New Years Goals post, you can see how one of my weak points is procrastination, and although I feel much more solid on the material we learned this unit than, say, the past unit, I still could have started studying sooner to clear up my schedule for other classes. From my last 20 Time update as well, my struggles with procrastination have definitely peeked through a bit during this unit, so I will endeavor to put more persistence into my goals going into the next unit. However, I do think that I should be proud of the progress that I have made this unit in learning new material, and I am looking forward to taking what I have learned with me going forward.

It's "Bin" Great So Far

Now that the time to write our 3rd blog post has come around, I am happy to report many new developments in my project. I now have created the basic frame of my compost bin out of a black, 31 gallon garbage can (pictured below). My dad helped me drill 6 rows of 8 holes, each approximately 1 cm in diameter and every row 5 inches apart from each other. The lid of the garbage can has 21 holes, and the bottom of the can was drilled as well in order to promote ventilation and the drainage of unwanted water.

Originally, I had actually not intended to use a garbage can for creating compost; I thought that this sort of container would not be big enough, since it did not fit the requirements of having a 3x3x3 ft^3 volume that one of my other resources had indicated. However, a brief venture into Home Depot left me without a concrete plan for the materials that I had wished to use, considering that I could not find adequate chicken wire, wooden snow fences, or even wood that I wished to use to make the compost bin. Hopefully this design(which was also on the plan I provided in my last post) will work out, and insulate the compost inside enough to hold heat.

After constructing the base for the compost, it was time to start actually putting things in it. To assist with this, I used a separate bin in the kitchen to hold the compostable feedstock(food scraps). 

This was crucial, as i didn't want any meat or dairy products(or god forbid, plastic) to find their way into the compost; however, I still had to fish out a couple pieces of bone here and there. 

As I mentioned in my previous post, I would have to start collecting dry and wet materials to put into my compost, and luckily enough, my house is located near quite a few oak trees with ample supplies of dry leaves, so I started off with a sizable layer of those leaves at the bottom of the compost.

Afterwards, I put in a layer of food scraps(from plant sources) to supply the "wet" aspect of compost, resulting in it looking a little something like this:

At this point in time, there is still some way to go before the bin gets to a large enough size to produce heat in the middle, so for the following weeks I will be documenting my progress in trying to do just that. With all the rain lately, it has been hard finding dry brown feedstock for the compost, so I might look for a way to stockpile oak leaves while they're still dry and available. Turning, which helps increase airflow and shorten the amount of time compost is created, is also a method that I will start using once the compost gets bigger, and I will keep this blog updated once I start doing it and see how(or if) it improves the way that the compost gets along. Also, it still remains to see whether this bin will work; if it fails to decompose the way that it should, then I might have to try and create another way to get rid of extra food scraps. Until next time, however, I'll keep working with this model and see how it goes. I will also try to look for nearby facilities to reach out and ask questions as well, and maybe even attend a few classes if y schedule clears up.

Mainly, what I have learned about myself is that I find it really hard to adhere to my goals or long-time projects when there are other things that are there to distract me in my schoolwork. I've struggled on the past with procrastination and other problems, but for this project especially I feel that I should work more towards breaking this habit of mine and putting this project in a higher priority. Our culture in school especially prevents us from focusing on the "big picture" at times, especially when it comes to doing well in school; I think that this project, in the long run, will help me stay focused in what I hope to accomplish, not just for 20 time. 

Owl Pellet Lab

In our Owl Pellet Lab, we were given an owl pellet to pick apart and needed to identify exactly what kind of animal(s) were part of this particular owl's diet. In my lab group, we found multiple bones and even skulls within the owl pellet, as documented by the pictures on the bottom, and even were able to identify a few of the bones that we as humans shared with these organisms.

We were able to find an assortment of animal bones

An animal's femur, pelvis, lower jaws, and other assorted bones

Upon uncovering all of the bones in the owl pellet, I hypothesized that one of our animals was a pocket gopher, due to certain characteristics of the skull that we observed. From the owl pellet that we got(which was 6.35 g, 45 mm long, and 33 mm wide), we had dug out a skull which was 36 mm long and 21 mm wide, with accompanying mandibles 16.5 mm in length and 3.7 mm in width. This fit in with the typical characteristics of pocket gophers(which have skull lengths of 30-42 millimeters), and although there were some discrepancies in the supposed mandible length(the ones that we found were significantly smaller), that can be attributed to the gopher being eaten prematurely. Additionally, the teeth of the skull were observed to be sharp and pointy, and have separate roots, which is one other characteristics that pocket gophers and voles share. Lastly, the shape of the skull did resemble that of a typical pocket gopher(as seen from the packet), which further solidified my suspicions that the animal we were dealing with was a pocket gopher.

The teeth of the skull were sharp and had individual roots

The skull looked almost exactly like the picture in the packet

As for ways that the animals were similar and different to our own human anatomy, the animals that we discovered had similar femurs, vertebrae, and scapulas as humans. The bones were surprisingly identifiable due to their similarity to human features in our own anatomy. In the scapula specifically, both shoulder blades in rodents and in humans have a fan-like shape, which made it easy to find. Things that differed from human anatomy were definitely the skull(and the teeth as accessories), the pelvis, and the mandible. The differences in the mandibles was most prominent, as humans only have one large lower jaw, while rodents seem to have 2.

The scapula looked a lot like humans' due to its similar shape

Rodents tend to have separated mandibles, not like humans

Learning the Framework

So far, I have been researching more and more about the topic of composting, and gathered numerous sources detailing exactly what types of compost there are and the characteristics of different compost bins. Although composting may seem self-explanatory on the surface, there are actually a lot of layers(no pun intended) involved with creating a successful system of decomposition. Just by researching about the different ways to construct holding units, a new world of information was opened up to me about which types of compost bins were most efficient(worm composting and turning units), how to choose a compost bin most suited to your abode, and whether or not turning the compost would make a difference. From this plethora of information I settled upon a plan of building a holding unit, the one which my resources hinted would require the least amount of work and delicacy, as long as I was able to provide at least an open, flat space of 3 ft x 3 ft x 3ft(which is able to fit in my back yard). I managed to find a plan as well for the construction of various types of holding units, which you can see for yourself here.

Next on my list was actually learning about what I should and should not compost, and how exactly to make the best possible environment for nature to do its work. Compost(at least in a holding unit that I plan to build) should be at least 3x3x3 feet in volume in order to properly hold in heat to speed up decomposition and keep pathogens away from the pile. The order of placing biodegradables should be first a layer of "browns"(dry, carbon ingredients) right above the ground, followed by a layer of "greens"(wet, nitrogen ingredients), alternating back and forth until a height of 3 feet is reached. Brown materials include any sort of dry yard waste like leaves and branches, which my house has plenty of due to our abundance of oak trees around, and green materials are things like food waste(but NOT including animal products of any sort) and yard clippings. At this point, I realized that I should plan to create a separate kitchen container for the green items that I wish to compost and separate out the things that need to be thrown away, so I included that in the general plan that I wished to follow. For some really interesting and important information concerning how to compost properly, you can refer to this resource for help.

Over the time that I have started working on my 20 Time project, I learned a number of things about myself, one of which was that it was hard to convince myself to stick to goals I had for a certain week when more pressing schoolwork was to be done. I had set a goal in my first 20 Time post to start building a compost bin by my next update, and I have not yet been able to accomplish this. Additionally, things that I struggled with during these first couple of weeks has been being out of town for a number of days, restricting my ability to get any work done on a project that is mostly material in nature. There was also the difficulty in doing much work during the allotted time in class besides research, because the majority of my project involves actually building a compost unit and composting at home, which I clearly cannot do at school. To overcome these obstacles, I will try to work more on my project at home through better planning of when to divide the work amongst my other homework, and trying to catch up over the upcoming break.

As for the next steps in my project, I am hoping to accomplish all of the steps I have listed previously and really start composting by the time of my next post, and detailing my findings through the audience on my blog to encourage others to join me in trying to reduce organic waste.

Reflexes Lab

In this lab, we learned about the various reflexes that we have in the body. As we know from learning about neurons, a reflex is the shorter pathway of certain reactions so that instead of firing signals all the way to the brain and back to the mentioned area, it first straight from a sensory neuron to the spinal cord, where it then bounces back to immediately signal mortar neurons to enact a certain response, oftentimes without us knowing it. Therefore, we sent out to find these reflexes and test them out for ourselves, with the photo pupillary, knee jerk, blink, and plantar reflexes, along with the general test of reaction time. All of these tests showed certain behaviors that occurred without our control, relating to the entire purpose of having reflexes which protect us by not sending signals all the way to the brain.

My eye in normal light

My eye once the flashlight was shown in my eye.

The first reflex we tested was the photopupillary reflex, which is supposed to make the pupil smaller in response to intense light. We tested this by closing both of my eyes and shining a flashlight into one, while the other while the other remained in the dark, and found that this reflex did happen(as seen from the photo evidence). This reflex worked because the sensory neurons detecting light(photoreceptors) only had to send a message up to the spinal cord, where it then bounced back to stimulate the ciliary body of the iris to contract in response.

The second reflex was the patellar, or knee jerk, reflex. Our knee is supposed to flinch or jerk outwards in response to a hard hit at the knee, and sure enough, after a test of this reflex, my knee did move without my intention. This reflex worked because the motor sensors in my knee were routed only to the spinal cord, after which the message to kick the leg was sent immediately through the motor neurons without my intention. Afterwards, we tested the reflex after doing 30 squats, and the reflex was less observed, due to the fatigue in  my muscles preventing the reflex from occurring super quickly.

The blink reflex was the next to come(in which we are supposed to blink in response to an oncoming object), and the test in this lab involving it included throwing a cotton ball at my eye with plastic wrap in front of my face. The sudden missile aimed at my face induced me to blink(uncontrolled by me whatsoever), showing that when unexpected things happen our reflexes really do help avoid disaster. Like all of the other reflexes, the blink reflex was induced by the quick timing of sensory neurons, the spinal cord, and motor neurons contracting the eye.

The plantar reflex, or the reflex in which your toes contract with the uncomfortable sensation of having a pen dragged up the sole of the foot, was unfortunately not observed in my test. A possible reason for why the reflex didn't occur in me could be that I was already thinking and anticipating the pen to go up my foot, so the surprise factor did not work as well as it should have.

Lastly, the reaction time test that we conducted was about dropping a ruler between my fingers and seeing how long it took for me to catch it. In the data table, below, you can see that my average reaction time was 0.28 seconds, which set the basis for the second test that we did.

This time, we would be testing the same thing but with the distraction of texting in our other hand, and, as expected, my reaction time was slower than it was before, and the average time was 0.33 seconds. This occurred most likely because the brain was so preoccupied with texting that it was unable to see the yardstick as quickly, and the sensory neurons in turn started the reflex to grab later than before.

Unit 6 Reflection

This unit was about the nervous system in its entirety, and some key themes and understandings were that the brain, although specialized to some extent, can be adapted to new environments and situations in order to better serve the body, and communicates within itself to divide up the work that needs to be done; dysfunctions of the brain are able in many ways to teach us how the brain normally works; and lastly, that the brain needs to be able to work with many other parts of our nervous system in order to truly function at its best.

The Clay Brain

We first started off by learning about the main parts and functions of the brain, the center of our nervous system. The brain is structured from bottom to top by the spinal cord, hindbrain, midbrain, and forebrain, and the closer parts are to the spinal cord, the more basic its movements and functions are. Then there are the parts of the brain, which include the brainstem(comprised of the medulla oblongata, pos, and midbrain); the cerebellum, which controls the body; the thalamus, which sorts data and sends it where it needs to go; the hypothalamus, which maintains homeostasis; the posterior pituitary, which sends out hormones; the cerebrum, which is in charge of integration; and the cerebral cortex, divided into 4 lobes and controls higher function thought and action. Those four lobes are the frontal lobe, which is involved in speaking  and is the "executive; the parietal lobe, in charge of sensation; the occipital lobe, in charge of vision; and the temporal lobes, which include auditory areas. As seen from the article "A Woman With a Hole in her Brain", loss of a certain part of the brain can result in a lack of ability to perform functions that that part of the brain does. The Sheep Brain Dissection also documents our journey in learning about the anatomy of the brain, as well as the Clay Brain.

We next learned how the brain works together to communicate and divide up the work amongst its various different parts. the whole idea of brain lateralization is that the brain "divides and conquers" when it conducts neural functions and cognitive processes between the right and left hemispheres of "A Woman Perpetually Falling". Other important characteristics of the brain are sensory areas, which contain the homunculus(the perception that your brain has of your body in accordance to the sensitivity of various parts of the body), and motor areas, which control muscle movement(where the right and left hemispheres come into play again).
the brain to make processes more efficient. The two sides(which control opposite halves of the body under a contralateral division of labor)communicate through the corpus callosum that connects the two. Contrary to this school of thought is the idea of brain plasticity, where parts the brain are able to take on functions of their missing or dysfunctional neighbors because the brain adapts and evolves in different environments constantly; this can be evidenced by the examples found in the reading

My Senses graphic organizer

Th mechanics of senses were discussed next, and we learned about special(or organ-specific) and somatic(or body) senses, which are received by receptors of all types. Sensory adaptation is the occurrence where our receptors are exposed to stimulus for so long that you no longer receive the message. The main specific senses were discussed, such as sight/vision, hearing, smell, and taste, and the corresponding organs, receptors, and sensory cells were identified as well. dissected a sheep eye in order to learn more about how light travels through the eye, and the functions of the different parts of the eye. Dysfunctions of sight include myopia(near-sightedness), hyperopia(far-sightedness), glaucoma, and cataracts; for hearing a choclear impact may be required allow sound waves to stimulate the auditory nerve. Taste and smell are lesser known for their dysfunctions, but we discussed how they(and sight and hearing) work as well. For this part of our learning, we

Neurons, probably the most important part of the nervous system, followed senses, and we learned that the 3 functions of the nervous system are sensation, integration(processing of sensory input), and motor function. The nervous system is divided into the central and peripheral nervous systems, the latter of which is divided into the sensory and motor divisions. The central nervous systems comprised of the brain and spinal cord, while the peripheral nervous system is made up of the surrounding nerves. The sensory division carries nerve impulses from the body to the brain, and the motor division carries nerve impulses from the brain to the muscles and glands. Subdivisions of the motor division are the somatic nervous system which consciously controls skeletal muscles, and the autonomic nervous system, which regulates involuntary or autonomic events. The automatic nervous system is at last divided into sympathetic and parasympathetic, which wither produces a change or the opposite that change. Neurons themselves have 5 main parts: dendrites, axons, axon terminals, the synaptic cleft, and the synapse. They are classified according to function or structure, but all of them conduct electrical signals much the same way. The nerve impulse starts off in the resting state, until something sets it off for depolarization(a switch between positive and negative charges). Depolarization occurs and propagation sends the signal across the neuron until it reaches to axon terminals to release neurotransmitter, and then the neuron is again repolarized to do its job once more.

Lastly, we covered the disorders of the CNS and PNS. Some diseases of the CNS are meningitis, an inflammation of the meninges, and epilepsy, a condition of the brain causing seizures. PNS disorders include the shingles, a reemergence of the chicken pox virus, and neuralgia, the sharp shock of pain that follow the path of a nerve. Addiction, believe it or not, is a disease as well, as it meddle with the brain's structure, pathways, and chemicals to create craving, compassion, loss of control, and continued use despite consequences in addicts.

Readings that we did this unit were "A Woman With a Hole in her Brain", "A Woman Perpetually Falling", both articles that discussed the topic in their title and relate to brain dysfunction, anatomy, and plasticity. Others included "How to Become a Superager" that explained how some elderly people could retain their younger minds through challenging themselves mentally all of the time(again, related to plasticity and evolution of the brain), "Fit Body Fit Brain" that discussed(like the previous one) how exercise can improve one's brain capacity, and "How We Get Addicted" that addressed the numerous ways that addiction can be considered a disease(relating to our nervous system disorders notes).

Definite strengths this unit included keeping up with readings and participating in class, but some weaknesses were seen in putting things off till the last minute and having a lot of work to make up. Studying for the test, too, was definitely not the best I could have done, which relates to my New Years Goals of trying to come up with better studying techniques. I did try to try new things this unit with drawing diagrams to help me study(mostly of the nervous system), but the main problem that occurred was the lack of time I had to prepare. Next time, I'll endeavor to invest more time into properly studying for the test. To end on an inquisitive note, some things that I am curious about are what parts of the brain/how much of the brain can be lost until brain plasticity is no longer able to occur, and how headaches occur.

Sheep Brain Dissection Lab

Question 1:

Labels of the anterior, posterior, cerebrum,
cerebellum, and brain stem

My drawing of the picture above

Question 2:

Question 3:

Myelin helps to insulate our nerves to decrease the time that messages can be processed.

Question 4:

Labeling the thalamus, optic nerve, medulla oblongata,
pons, midbrain, corpus callosum, and hypothalamus

My drawing of the picture above

Question 5:

Question 6:

A cross sectional cut of the cerebrum

My drawing of the picture above

Relate and Review:

For this lab, we dissected the brain of a sheep, and identified the different parts that we were able to uncover while doing it. First, we labeled the anterior and posterior of the brain and the cerebrum, cerebellum, and the brain stem after attempting to remove some of the meninges.  The brain was then cut longitudinally in order to see some of the myelination of white vs. gray matter, and we labeled the thalamus, optic nerve, medulla oblongata, pons, midbrain, corpus callosum, and the hypothalamus, before cutting the cerebrum in half once more to reveal further details on the differentiation of gray and white matter. In this lab, we were also tasked with finding the functions of each of the parts that we labeled on the heart, and in this way, were able to learn both the anatomy and the physiology of the parts of the brain. Like the Sheep Eye Dissection Lab, the association of what everything does while analyzing the physical characteristics of certain parts helped me really understand how the parts of the brain work together to make us the way we are.