It's my last post on this blog! This is a bittersweet moment. For my final post, I will be reflecting on the 20 Time TED Talk that Hayley and I delivered in class.
You can watch the actual TED Talk here...
Overall, I thought the TED Talk went really well. I thought Hayley and I were well prepared, and I attribute that to the numerous times we practiced beforehand. Public speaking is relatively easy for both of us, so we weren't concerned too much about stage fright or nervousness. I was instead just excited to share our progress with the class. I thought did a good job explaining our thinking process and how our project evolved throughout the time we had, and we acknowledged all of our setbacks and stated how we learned from them. I wish we could have included the video we took at our event, however, that would have made our presentation much longer than 5 minutes, and we had more important information we had to include. I would grade us relatively well, as we included all the necessary information while delivering it without any complications. We were well-practiced and well-prepared, and we took it very seriously. We wanted to present first so we wouldn't compare ourselves to other presentations before us, but it actually helped to watch some other presentations as they helped us calm down and prepare also. Overall, the preparation for the TED Talk as well as the 20 Time project itself have helped me become a more organized and mature person.
Hayley and I did a costume collecting fundraiser at the local dance studio where I teach. We chose to focus on donating dance costumes because it’s a shared experience for both of us, as we were both in cheer and saw firsthand the costs of doing an activity you love. I grew up doing dance and have easily spent thousands of dollars on costumes alone. Some of my dance friends had to give up their dreams of becoming professional dancers because the cost is so astronomical. Dance is so important and beautiful, it would be a tragedy if any kid weren’t able to pursue this art because of rising costs.
Our goal was to promote awareness for the cause, collect costumes to donate so we could make a concrete contribution, and also work on our event planning skills as well as organizational skills. Initially, we did not have a set plan, but through a lot of careful thinking, we decided a fundraiser would be the most effective way to get the community involved while also making a difference.
We had trouble with planning the event at first. We are both pretty busy people, so planning a date that worked was very tough. We thought we had a day that worked, but we realized a couple days before that we planned it on Easter Sunday, so we had to change that. Eventually, we had a successful event. We played games, planned fun little activities, and taught a dance combo. We had around 25 girls show up and we collected a TON of costumes, which we donated to Traveling Tutus, an organization based in Florida that provides costumes to low-income communities around the world.
We learned a lot about planning, especially paying close attention to detail. We also learned about how to advertise an event, utilizing flyers and also electronic means of communication to get our voices out there. It’s not always easy to keep control of a large group of young girls. We had to seriously plan our activities so there was no downtime, as well as find fun and engaging games, clean music, and choreograph and teach a dance. If we could do this again, we would want to make the event bigger and more successful. With more time, we could have planned something in the public park and accessed more communities, such as coordinating with local elementary schools. I also would have broadened past just dance, including theater costumes or even sports uniforms for low-income communities.
Next, I plan to continue teaching dance and collecting used costumes from my students. I will make regular donations to Traveling Tutus, as they will be able to put the costumes to better use than we can.
I would give myself an A, as I am very satisfied with the way the event turned out as well as our yield in costumes. We were focused on our goals, and we pushed through any hardships we faced. I learned a lot about event-planning and the importance of organization. In our final blog post, we included pictures and a video of a few dancers from our event. You can access those here.
Ted Talk Outline:
Describe our idea and why it’s important to give back to this cause.
Talk about our process of planning.
Describe the actual event and how it went. Our takeaway and what we learned.
In this lab, we dissected a standard frozen chicken. One thing to keep in mind is that these are meat chickens, bred specifically to be fat in certain places to be nice and plump for human consumption. The goal of this lab was to understand how muscles, tendons, and bones work in collaboration to exhibit movement in the body. Muscles cause movement through contraction and relaxation, and connect to our bones with tendons. While a human and a chicken are very clearly different, there are a lot of similarities to be found, especially in the chicken wing versus the human arm. The two main muscles of the wing are the biceps brachii and the triceps humeralis. When the biceps brachii contracts. the triceps humeralis relaxes, and vice versa. The biceps brachii has its origin site on the humerus. The point of origin remained fixed as an anchor even when we manipulated the rest of the muscle, as we learned previously while we studied muscles. This is just like the human arm, for when our bicep flexes and our triceps relax, our arm bends.
Pectoralis Major and Minor
Also, the trapezius and latissimus dorsi muscles worked similarly in humans. These control the motions of the shoulders. However, there are some differences between humans and chickens. Most notably, there is a difference in the pectoralis muscles. This is what we eat when we eat chicken breast. Yum. These were absolutely humongous on the chicken, and on humans, except for maybe Dwayne "The Rock" Johnson, these are proportional to the rest of our body. The pectoralis major in chickens pulls the wing ventrally and the pectoralis minor pulls the wing dorsally. These functions are different from the human body because we use our arms to do more than just fly.
The Iliotibialis or IT band
The Deltoid
The Brachioradialis and the Flexor Carpi Ulnaris
Blue pin: Gastrocnemius Yellow pin: Peroneus Longus Black pin: Tibialis Anterior
We ended last unit, the skeletal system, talking about joints. We had a nice transition to this unit, the muscular system, by beginning with synovial joints and their different movements, including gliding, angular, rotation, and special movements. In addition to different types of movement, there are also different types of synovial joints. These are planar, hinge, pivot, condyloid, saddle, and ball and socket joints. Examples of those would be the carpals in the wrist, the knee, the neck, the fingertips, the thumb, and the hip, respectively.
We then transitioned into learning about muscles, beginning with their basic characteristics. Muscles have many different purposes, such as maintaining posture, moving bones, stabilizing joints, and generating heat. As we learned earlier in the year (It feels like just yesterday), muscles can be classified as smooth, skeletal, or cardiac. Smooth movement generally controls involuntary movement, while skeletal controls voluntary movement. Cardiac muscle is located in the heart. Muscles must have one or a combination of these characteristics: contractibility, extensibility, elasticity, and excitability. Fascia holds the muscle together by wrapping around each muscle fiber as well as bundles of fibers, and finally surrounding the entire muscle. A muscle is anchored at its origin site. It stays still and while the rest of the muscle moves so that the insertion side can contract towards the origin site. Muscles work conversely: when one muscle contracts, another must relax. The contracting muscle is called the prime mover, and the relaxing muscle is the antagonist. The English Major in me likes that name. In addition to these two muscles, a synergist muscle works to prevent unnecessary movements, while fixator muscles anchor and stabilize the site of origin of the prime mover. Muscles are characterized and classified according to their location and their function.
In order to understand how muscles worked, we needed to examine them on a microscopic level. This is the most remarkable part about muscles. Let us go in order from larger to smaller. The whole muscle is made up of muscle fibers, also known as myofibrils, which are comprised of sarcomeres. Within each sarcomere, there are two protein filaments, actin and myosin, that are arranged to overlap. These sarcomeres contract as individual units, causing the entire muscle to contract also. The process of muscle contraction is as follows: a motor neuron sends an action potential to the muscle, which stimulates the release of Acetylcholine, which then binds to the receptors located on the muscle membrane. This activates a second action potential, which triggers the release of Ca2+, which attaches to troponin on a TT complex, changing its shape. By changing the shape, the TT complex can pull away from the myosin-binding site on the actin, and ATP attaches to the head of the myosin. When the ATP splits into ADP and P, which energizes the head and makes it swing forward in an energized state. The P detaches so that the head can reattach to the myosin-binding site on the actin. When the ADP detaches, the head returns to a resting state and swings backward. This continues until the action potential stops and CA2+ is no longer being released.
When we exercise, our muscles utilize different types of twitch fibers. These are the slow twitch, fast twitch a, and fast twitch b. The slow twitch is dependent on oxygen and stores little glycogen, and it is red in color. It is the slowest to fatigue, which makes it effective for long exercise. Fast twitch a fibers are also oxygen dependant, but they store a lot of glycogen and are pink in color. Fast twitch b fibers require no oxygen and therefore need no blood vessels, which is why they are white in color. These are helpful for short, intense bursts of exercise. Examine the effects of stretching on muscles in this analysis of an article that I did previously, here.
My personal favorite of this unit was learning about muscles on a microscopic level. I had no idea that these sarcomeres even existed. It was pretty mindblowing to learn about. Our bodies are like little factories! In other personal news, 20 Time is coming to a close, which is a bittersweet ending to a very enjoyable project. Hayley and I had a lot of fun despite our rocky start. We are in contact with a non-profit who would be delighted to receive our donation. My heart is happy that we are raising awareness and providing help to a cause very dear to me. My New Years Goals have been going okay in regards to school, however, I am still missing the Chicken Dissection Lab, but I plan on making that up with Hayley soon. Works Cited https://upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Sarcomere.svg/500px-Sarcomere.svg.png https://en.wikipedia.org/wiki/Muscle_contraction
Relate & Review:
As we learned previously through our notes and a video, muscles are comprised of segments called sarcomeres. These can contract and elongate according to whether the muscle is relaxed or engaged. When we stretch, our sarcomeres elongate until each one is fully stretched and the muscle fiber is completely relaxed, then collagen fibers in connective tissue "pick up the slack" and pull in the same direction as the stretch. The main nerve endings in muscles are proprioceptors (mechanoreceptors). Like Mr. Orre said, these tell your where you are in space. Basically, if you close your eyes and lift your arm, the proprioceptors tell you how high your arm is raised. They are present in all nerve endings of joints, muscles, and tendons. Muscle spindles are the most prevalent proprioceptors in the muscles. The muscle spindle stretches when a muscle is stretched and triggers an action called the stretch reflex, which contracts the previously stretched muscle. However, this reflex can be reduced through prolonged and frequent stretching. This article mentions dancers as some of the few humans that possess very little to no stretch reflex, as they stretch like crazy.
Quotes:
"While this type of control provides the opportunity for the greatest gains in flexibility, it also provides the greatest risk of injury if used improperly." (2) - This quote was interesting to me as it shows the potential risks for pushing your body to the max in order to reduce your stretch reflex. I think this shows the lengths dancers are willing to go to in order to further their careers. It is sad that so much is expected of people so that they can stand out and be better. "Just as the total strength of a contracting muscle is a result of the number of fibers contracting, the total length of a stretched muscle is a result of the number of fibers stretched -- the more fibers stretched, the more length developed by the muscle for a given stretch." (1) - Strength and flexibility are inversely related based on sarcomere length. This unit is still blowing my mind as I never even knew sarcomeres existed beforehad, I just thought the muscle as a unit would move like pulling taffy at a candy shop. Now it makes more logical sense. "Another reason for holding a stretch for a prolonged period of time is to allow this lengthening reaction to occur, thus helping the stretched muscles to relax. It is easier to stretch, or lengthen, a muscle when it is not trying to contract." (3) - I have witnessed this firsthand! It's the coolest phenomonon. I remember sitting in the splits hating life as I couldn't get all the way down, and I was clenching all my muscles, then all of a sudden, my hamstrings just relaxed and it was way easier.
A common problem for athletes, especially athletes like dancers and gymnasts who place major stress on their hip joints, is Snapping Hip Syndrome, or the snapping movement of a muscle or tendon across a bone. I propose a solution in order to reduce this condition: laterally running tendons connected to these muscles and tendons that help alleviate the stiff movement and support them as they move across the bone as well as bigger bursa to reduce friction.
Main Body:
The Hip Joint:
The hip joint is arguably one of the most important joints in the body. Without it, humans would be confined to sedentary lifestyles, as we would be unable run, walk, jump, or bend the knees. It is an extremely movable and flexible joint, which is especially evident when dancers perform kicks such as battements. The hip is a ball-and-socket synovial joint. The two bones connected in the joint are the hip bone, also known as the pelvis or the scientific name os coxa, and the thighbone, or femur. On the ischium, or lower bone of the pelvis, there is a cup-shaped socket known as the acetabulum. The femur’s rounded epiphysis is the ball part of the joint. The joint is lined by hyaline cartilage, which covers both the acetabulum and the epiphysis of the femur. The hyaline cartilage is vital in providing a smooth surface for the bones and also in absorbing shock. The hip joint also has another layer of protection in the bursa, a sac filled with synovial fluid and lined by a synovial membrane to further lubricate the joint. The hip joint is surrounded by dense ligaments to prevent dislocation, such as the iliofemoral ligament and the pubofemoral ligament. The iliotibial band, or IT band, runs on the outside of the hip joint all the way down to the knee. The iliopsoas tendon connects to the inner thigh. Near the ball of the femur is the femoris tendon. The hip joint allows for an extraordinary amount of movement, allowing for 360 degree circumduction and an almost 90 degree lateral axis. It is also extremely tough, as it endures multiplied force during activities such as running.
The Problem:
A common condition that occurs with athletes such as dancers and gymnasts who put repeated intense stresses on their hips is Snapping Hip Syndrome, also known as Dancer’s Hip. This is a medical condition in which a muscle or tendon incorrectly and rapidly moves across a part of the hip bone or the top of the femur, causing a popping or snapping sound and sensation. This is what you hear when a ballerina lifts her leg, and commonly sounds like a “crack.” This condition is difficult to prevent, as it occurs in most athletes that must keep up the demand on their bodies. While usually painless, prolonged cases of Snapping Hip Syndrome can lead to bursitis, or inflammation of the bursa.
The Redesign:
The main problem with snapping hip syndrome is that the movement across the bone by the muscle or tendon is too sudden and uncontrolled. To combat this, I propose the addition of two tendons that run horizontally across the muscles and tendons. This way, the moving muscles and tendons will have extra support running in the direction of their movement that will prevent the erratic snapping. These new tendons will share the blood and nutrient supply of the muscles and tendons they support, although the number of capillaries may need to be increased to keep up with increased blood demand. I also believe the size of the bursa should be increased in order to prevent friction.
Discussion:
Growing up as a dancer, I am all too familiar with Snapping Hip Syndrome. Almost every class during plies, at least three girls’ hips would loudly “pop,” sending the rest of us into a fit of giggles. Dance places a lot of pressure on your hips, as you’re expected to be able to lift your leg past your head and turn out your feet past a natural level. While at the time the condition seems harmless, more annoying than anything else, after time it can cause pain and inflammation that may not go away for a while. I know two people already who have needed hip surgery before the age of 20 from dance. This is worrisome as they will have to deal with repercussions from this condition for the rest of their lives. My proposed design was intended to help make the movement across the bone more natural. Because the snapping movement is erratic and rapid, the two tendons that run laterally will help smooth the movement out and control its speed. A problem may be how those tendons get nutrients from the body. While right now I believe that these tendons could share entry points and capillaries with the existing muscles as they could just be very small in comparison, this may not be enough to nourish the tendons. This assignment was semi-difficult to make plausible. The human body is complex already, so trying to make a complex joint even more specialized was a challenge. While there currently is no way to prevent Snapping Hip Syndrome other than not participating in certain sports, there are some ways to prevent further damage. Some ways include reducing the intensity of activity, icing the affected areas, or taking pain relievers to reduce inflammation.
Works Cited:
Biel, Andrew. Trail Guide to the Body: How to Locate Muscles, Bones and More. Boulder, Colo: of Discovery, 2008. Print.
This unit, we dragged the skeleton out of the (supply) closet and learned all about bones! The skeleton is actually an organ system called the skeletal system, and while at first, it may seem like bones are relatively inanimate, bones are actually constantly undergoing change and vital processes.
The different types of bone cells. Image courtesy of Wikipedia Commons.
Let us first examine the anatomy of a bone on a microscopic level. Within the bone, there are osteogenic cells, and conveniently, "Osteo" means "Bone" in Greek. Obviously, our bones don't stay the same size throughout our entire life, otherwise, we would remain baby-sized forever. We actually undergo a process called ossification, or osteogenesis, in order to remodel and grow our bones. This process takes place from fetal development to around 25 years old, when our bones are completely ossified. This utilizes two types of cells: the osteoblasts and osteoclasts. Osteoblasts are the bone-building cells, and osteoclasts are the bone-destroying cells. Together, they work in harmony to remodel the bone in a constant state of flux. As old bone is destroyed, new bone is formed, keeping our bones nice and fresh. In fact, we create an entirely new skeleton approximately every 7 years! Mature bone cells are called osteocytes, and they conduct the daily processes of bones to maintain homeostasis. Bones have a compact bone exterior that is hard and dense, and a spongy bone interior that is more porous and filled with bone marrow/blood vessels. Through the Haversian Systems, osteons, or cylindrical canals, contain the bone's blood supplies. They are surrounded by lamellae which run perpendicularly to the osteons in order to provide more sturdiness. The lacunae are small spaces in the bone that contain the previously mentioned osteocytes.
Now we will look at bones on a macroscopic level, as well as discuss the different types of classification of bones. Bones can be classified into 4 different groups: long, short, flat, or irregular. Long bones are longer than they are wide, like the femur. Short bones are cuboidal shaped, like the carpals in your hand. Flat bones are, well, flat, like the ribs or the sternum. Lastly, irregular bones are the bones that don't fit into any other category, like the odd-shaped pelvis. In the skeleton, there are also joints that allow for movement in our bodies. Fibrous joints are surrounded by dense connective tissue and are synarthrosis, or immovable. An example would be the sutures of your skull. Cartilaginous joints are surrounded by cartilage and are amphiarthrosis, or allow for little movement. Synovial joints are the joints we typically think of, and they are surrounded by a joint capsule containing synovial fluid. They are diarthrosis, or fully moveable, and include joints like your elbows. To see a fun activity where we examined and classified bones on our own of rodents, refer to the Owl Pellet Lab.
In this lab, Michelle and I analyzed an owl pellet, which is the regurgitated remains of a barn owl's meal (a yummy rodent or bird) that could not be digested. When we first unwrapped the pellet, it looked like a lump of fur. It felt like I was petting my old pet hamster. After we began examining the inside and carefully crumbling away the dark fur parts to expose the bone, it was evident that we had multiple rodents in our pellet, as shown by the 11 humerus and femur bones we found. We believed we had vole bones in our pellet. Our reasoning for this was: the shape of the humerus bones, which were long but thin and had the defining triangle spike on the side; the shape of the tibias and fibulas, which were fused in our case; and most notably the shape of the skull pieces, which had the large sharp front teeth and the tiny back teeth, as well as the deeper eye socket. These characteristics clearly point to a vole, as the other rodents ehad differently shaped humerus bones (the shrew's lacked the spike on the side and the mole's was vaguely circular), fibulas and tibias, or skulls (the shrew had an indiscernible eye socket, and the mole's was also more shallow).
The bones we found had some similarities and differences to a human skeleton. The human humerus is also in the shape of a long line. Both the vole and the human humerus has two wider epiphyses at each end of it. The skull also has the same basic features, such as an eye socket, the sharp teeth like the canine teeth in humans, and the flat molars near the back of the jaw. However, the vole has the distinct triangle on the side of the humerus, which humans lack. The radius and ulna are also very different in the vole, with the ulna being remarkably thin in comparison to the radius. (Maybe vice versa.) The tibia and fibula were also fused in the vole and not in a human.
This unit covered the sense and the brain, beginning with the overall anatomy of the brain then going more into depth on the function of each part of the brain. We then covered the two hemispheres and lobes of the brain. The right hemisphere focuses on overall context, while the left brain focuses more on specific facts and details. The brain is also very flexible and adaptable and can heal from trauma or in response to new stimulation. We then moved onto our 5 senses and how the brain receives and reacts to sense stimuli, through sight, hearing, touch, taste, and smell. For example, the brain contains proprioceptors to sense pain and thermoreceptors for heat. Neurons send signals from the external stimuli to the brain, through integration in either the Peripheral Nervous System or the Central Nervous System. Each different system represents a section of the overall neural system and plays an important role in integrating messages and responding to the motor neurons to perform a reaction.
This is the analysis of the sheep brain dissection lab we did this unit, and here is the sheep eye dissection lab. Both were engaging and helped me really understand the location of each part of the brain or eye.
We read many interesting articles this unit. The first was "How to become a Superager" by Lisa Barret.This article was about how older people called "superagers" are able to function and have the same brain capacity of that of young people. While they might look old physically, mentally they are still functioning at their peaks. To keep the brain at this level of function, you must engage it through solving challenges, exercising, and doing difficult problem solving beyond simple sudoku. The second was "Fit Body, Fit Brain, and Other Fitness Trends" by Gretchen Reynolds. She explains how exercise also helps to keep our brain fit, most notably through an increase in neurons. She mentions studies that show how weight training can lead to fewer lesions in the brain's white matter. She also discusses how in a set of twins, the twin with more muscle mass has a stronger brain in the future. We already knew exercise is super important to staying healthy, and this just reaffirms that. The last article we read was "How We Get Addicted" by Michael D. Lemonick, a former addict and alcoholic who overcame his addiction. Humans innately want to feel pleasure, which explains why they've turned toward drugs since the beginning of time. Drugs create a salience overdrive, causing an uncontrollable desire that turns into a severe craving. In addicts, the reasoning part of our brain that tells us, "Hey, drugs are bad!" doesn't function correctly, allowing them to continue in a negative cycle of addiction. This unit has been hard, but this time of the year is never easy for me. It's hard because I'm not trying to be the typical senior who flakes on responsibility second semester, but I just feel overwhelmed and emotional all the time. It's not like I want to feel like this or that I'm actively trying to be a bad student, but it's difficult to balance and prioritize things when I feel like I can't focus on anything but the negatives.
In the reflex lab, we tested different reflexes on our lab partners. These reflexes included the photo pupillary reflex, the knee-jerk (patellar) reflex, the blink reflex, the plantar reflex, and our general response time in reaction to a stimulus. In essence, a reflex occurs on an arc, the most simplistic one being monosynaptic. That means the reflex has only two neurons: a sensory neuron and a motor neuron. Most reflexes, however, tend to be polysynaptic, containing multiple relay neurons in between. Most sensory neurons synapse in the spinal cord rather than the brain, allowing for a quick reaction time without the need for transferring information to the brain.
Claims Evidence Reasonings:
The photo pupillary reflex is when the pupil dilates in response to a changing environment. The evidence of this reflex is visible in the video we took of Michelle's eye after shining a flashlight into her eye that had been deprived of light for two minutes prior. Her pupil clearly increases size. This is a response that controls the amount of light entering the eye and adjusts rapidly to quickly adapt to a changing external environment, allowing for humans to see faster to react to any threats.
The patellar reflex is a contraction of the thigh muscle in response to a light tap below the kneecap. We know that a mechanoreceptor sensory receptor felt the pressure of the tap and in turn, through a monosynaptic reflex to the spinal cord, the thigh muscle contracted to kick the foot forward. We saw this happen after Hayley and I took turns tapping each other below the knee, and each time our feet involuntarily lifted. We found out that this occurs as a way to allow humans to catch their balance: the contraction of the quads puts the torso back upright during a falling motion.
The blink reflex is the closing of the eyelids in response to a rapidly approaching object, whether it touches the eye or not. When I threw the cotton at Hayley, she not only blinked, but she flinched too. Same with when I pretended to punch her. ;) The reasoning for this reflex is so that no foreign objects get in the eye.
The plantar reflex is the clenching of your toes when something drags along the bottom of your foot. When Hayley dragged her pen across the sole of my foot, I not only giggled and squirmed as I am severely ticklish, but my toes also clenched inward. I think the reasoning for this is that when your foot feels the ground while you're running, your toes clench downward to allow for more grip on the ground to propel you forward in your run.
Our response time was the time it took to react to a stimulus, in this case, a falling ruler. Hayley had the faster average response time, at 0.20 seconds. However, after we introduced texting into the experiment, both of our reaction times slowed significantly, with hers slowing to 0.30 seconds. This is because it's extremely difficult to multitask and devote attention to both texting and catching the ruler.
In this lab, we dissected a sheep's brain to observe the different sections of the brain and how they work in relation to each other. As we learned before, the brain is divided into different sections. By simply observing the surface of the brain, we can distinguish a few structures, including the cerebrum, which is the front parts of the brain, the cerebellum or bell-shaped lump near the back of the brain, and the brainstem, which protrudes out of the back and bottom of the cerebellum. The cerebrum controls higher brain function, such as thought and action. The cerebellum receives sensory information and regulates voluntary movement, like posture for example. The brain stem controls the flow of messages between the brain and the rest of the body, while also controlling basic bodily functions like breathing.
After making a longitudinal incision to sever the brain into two halves, the right and left hemispheres, even more structures became apparent. What looked like a mere chicken cutlet at first glance now became a complex and organized network of thoughts, each specialized part of the brain controlling its own important part of the sheep's life. Now we could see myelin layers, which appeared as a paler color than the surrounding brain tissue. You can clearly see a
tree-shaped branching bunch of myelin fibers in the cerebellum. Myelin acts as an insulator on the neurons to speed up the process of interpretation, which is why it concentrates in areas of the brain that require ultra-fast processing, like the cerebellum, which I thought looked a lot like cauliflower. We observed the corpus callosum, which was the only thing connecting the two hemispheres, allowing for communication between the two. This is what was severed in split brain patients. We also saw the midbrain, the collective of multiple structures involved with the central nervous system, vision, hearing, etc. Towards the front of the brain was the optic nerve, which transfers visual information from the retina to the brain. The first lump, going from the posterior to the anterior of the brain, was the pons, which controls breathing, communication, taste, hearing, balance and more. The next bump was the medula oblongata, the regulator of breathing, heart and blood vessel function, digestion, sneezing, and swallowing. In front of that was the thalamus, which correlates consciousness, sleep, and sensory interpretation, and then the hypothalamus, which connects the nervous system to the endocrine system through the pituitary gland and the hormones released from it. After making a cross sectional cut, we could see even more clearly the aforementioned myelin, whose presence created white matter. The darker brain matter is called grey matter.
Did you know that the image formed on our retina of everything we see is actually upside down? You may be thinking, "How do people see normally without constantly doing a handstand, then?" I shall explain this and the wonderful process that is vision now, through the aid of a dissected sheep's eye.
Our sheep had a beautiful blue iris.
The tapetum lucidum reflects the flash off my camera.
When light enters our eye, it passes first through the cornea. This is the tough exterior on the eye, which mainly serves as protection. Next, the image passes through the aqueous humor, which is a clear liquid in between the cornea and the lens. You can see the liquid on the mat of the dissection board, as it leaked out after the cornea was punctured. The image then passes through the pupil, which contrary to what you may think, is not a tangible black dot in the center of your eye. The pupil is actually a hole, an opening in the iris that allows light to pass through. The iris is the colored part of the eye, and it comes in many colors such as brown, blue, green, hazel, and purple if you're Elizabeth Taylor. The image passes through the pupil opening onto the lens, a very interesting structure that can actually change shape! The lens changes shape in order to focus light on the retina. This is what you see when someone's "pupils dilate." Their pupils seem to grow in size, which happens to allow more light in while in a darker environment. In sheep eyes, there is a secondary feature to allow even more light to be reflected into the retina at night called the tapetum lucidum. This is the reflective and iridescent part on the inside of the eye. After passing the lens, the light passes through another clear liquid called the vitreous humor, which is the jelly like substance sliding out of the eye in the attached pictures. The image then hits the retina, which contains the photoreceptors for vision, and is displayed upside down. Now, the brain does some pretty remarkable work to interpret the image. Where the retina and the optic nerve meet is a small divet called the "blind spot." The electrical signals are sent via the optic nerve to the occipital lobe, located in the back of the head. In the occipital lobe, vision is interpreted and flipped through complex tasks in order to match our perception with reality. Some studies say that at birth, babies still see the world upside down until the brain adjusts and corrects itself!
In the excerpt "The Woman Perpetually Falling..." from Norman Doidge's book The Brain that Changes Itself, a woman named Cheryl suffers from a severely debilitating vestibular disequilibrium symptoms, brought upon by a prolonged use of the drug gentamicin. This drug is known to be harmful, but is used anyway because it is cheap and effective. This highlights a dangerous conundrum: use cheap and easily attainable medicine, or ensure the safety of patients even if it sends them into a deep debt? Cheryl only has 2% function of her vestibular system, which is responsible for regulating the sense of balance. It is comprised of 3 semicircular canals that send signals of changing external situations, such as a tilting head, so the body can adjust accordingly. Without this system, Cheryl feels as though she is constantly falling, her body weighed down with the added gravity of her condition. In addition to this seemingly physical weight, her mind is constantly exhausted and overworked. Since she is always focused on not falling, her mental capacity has no room for seemingly mundane tasks such as memory, thinking, etc. However, a doctor presents a remarkable solution: "a construction hat with holes in the side and a device inside it called an accelerometer" (5). This deceivingly simple device changes Cheryl's life, allowing her to finally feel normal for the first time in 5 years. I was moved by her shift in demeanor after she experiences stability, when she "starts clowning and showing off" (9). It is as if she can finally be herself, free of the mental and physical symptoms holding her back. This truly shows the correlation between physical health and mental health. Additionally, I was saddened by her disappointment when the effects wore off, describing herself as "tired, exhausted... depressed" (9). This resonated with me as she reverted back to her pain-ridden self, having experienced normality to only recede into her former shell. Thankfully, Cheryl's use of the accelerometer caused the symptoms to disappear completely, giving her life back.
In this lab, we created two models of different viewpoints of the brain: the right cerebral hemisphere view and the left hemisphere along the sagittal plane. We used different colors of Play-Doh to represent different parts of the brain, creating a colorful visual model of the locations of parts of the brain. For example, we used orange to represent the frontal lobe on the right cerebral hemisphere.
The newscientist.com article, "The Woman With a Hole in Her Brain" by Helen Thomson, describes a Chinese woman's remarkable survival without an entire cerebellum. Her condition led to only motor deficiency and speech problems, and she has surprisingly survived past the age of 24. The cerebellum is responsible for controlling voluntary movement and balance, as well as other motor functions like speech. Most patients with this condition pass away at an early age, which makes this woman's survival even more exceptional. Doctors say other parts of her brain, such as the cortex, are compensating for the absence of the cerebellum by taking over its functions.
What would happen if someone were born without, say, a pons? The pons relays signals from the forebrain to the cerebellum. It also contains nuclei that regulate sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture. Without a pons, the brain could not function even basically, as no information would be transmitted. So no, a person cannot survive without a pons.
The folds in the small intestine, which increase surface area
for better absorption.
This unit was focused on a few major organ systems in the body: the digestive system, the endocrine system, and the lymphatic system. Each system is interestingly interconnected. The digestive system consists of the mouth, pharynx, esophagus, stomach, appendix, small intestine (duodenum, jejunum, to ileum), the large intestine (ascending colon, transverse colon, to descending colon), rectum, and anus, traveling through those organs respectively. This pathway is the alimentary canal. The digestive system consists of digestion and absorption, digestion being the mechanical and physical breakdown of food through various processes. These can include peristalsis, which is the contraction movements of the esophagus, stomach walls contracting, chemical changes in the acidic stomach, and digestive juices/enzymes in the small intestine. Absorption is the absorbing of the broken down nutrients into the blood stream. This occurs due to the many folds in the small and large intestines, which are actually over 28 feet! We explored the surprising length of the intestines in our lab, which I debriefed here.
We also learned about fuel metabolism, which changes depending on what state your body is in. If you have just eaten, you are in the fed state, and the sugars you absorbed in the digestive system travel to the liver, where they are converted into glycogen. The pancreas releases insulin to stop the release of glucagon. The amino acids, fatty acids, and glucose are sent to body cells to be stored as adipose tissue. If a person consumes and does not expend the energy stored in the form of fat, said fat will accumulate, causing obesity. Obesity can lead to many health complications, one of which is diabetes. Diabetes is a disruption in fuel metabolism. Diabetes can be one of two forms: Type I diabetes or Type II. Type I occurs when insulin is not correctly produced by the body, and those who are diagnosed are dependent on insulin shots. Insulin is a hormone that allows glucose to be absorbed into cells, triggering the migration of Glut4 receptors to the outside of the cell membrane, which allow glucose to enter the cell. This only affects 5-10% of all people with diabetes. The more common form of diabetes is Type II, which occurs when the body is insulin-resistant, meaning that insulin's intended effects do not work in the body. If not correctly managed, diabetes can be deadly. My grandfather had Type II diabetes, and my brother was pre diabetic until he changed his lifestyle.
Insulin's effect on Glut4 receptors in cells. Exercise also triggers the movement of the Glut4 receptors.
The main struggle I had this unit was missing the Fuel Metabolism lecture. The printed handout had run out by the time I went to get one, so I had to write the whole thing by hand, which muddled the information, and also meant I don't have some diagrams in my notebook. I also realized that it was incredibly complex, and I am still slightly confused on exactly what some terms mean. In regards to my New Year goals, I am doing mas o menos. I completely forgot that we had a temp check, and at that point I still had not done my Fuel Metabolism notes, so that went poorly. I wish I had taken initiative and done them earlier. However, I am eating much healthier, and I've eliminated my snacking habit. Now I stick to my 3 wholesome meals a day, with one small snack before I go to work. Having a job and being a second semester senior is a catch 22; now that it is competition season, I have increasing obligations and commitments to my students, (including rhinestoning over 45 costumes...) and I have to continue to do well in school while juggling changing social aspects.
1) In the Digestive System Lab, we made a model to represent the length of our digestive system from mouth to anus. To do so, we used different colored yarn to represent each different organ/part of the system, and measured certain parts of our bodies and heights to calculate the size of each organ. For example, our stomach was the length of our thumb to pinkie finger while making the "hang loose" sign. Our bodies are very specialized, and remarkable in almost unimaginable ways. Many people describe me as "tiny," so it's crazy to think that so much stuff is in my body. We calculated the length of our digestive system, which is staggeringly longer than expected. The "takeaway" from the lab is that organs so long and large can fit into such a small space.
2) I am 5 foot 2 inches tall, fairly short for my age and gender. This is 62 inches. The length of my digestive system is 8.604 meters, or 338.74016 inches. That is actually insane to think about. I think the only way this length of organs is able to fit in my abdomen is through tons and tons of folding and coiling. It is compressed into many micro-folds, increasing surface area while maintaining the small volume.
3) I think it takes 3 1/2 hours for food to move through the digestive system. I shall now look up the answer. It actually takes about 6 to 8 hours. I find this surprising because sometimes when I eat dairy foods, (I am intolerant) it seems to only take 20 minutes to pass through. (TMI) I know that this is the body's mechanism of getting the dairy out of my body as quickly as possible, but it seems surprisingly fast compared to the normal 6 to 8 hours. This may be a factor that influences the time it takes, in addition to things like fiber intake.
4) Digestion is the breaking down of food into smaller particles and molecules, done mostly by the mouth, the stomach, and the small intestine. Absorption is the actual intake of those broken down molecules into the bloodstream for use throughout the body, taking place mainly in the small intestine and large intestine.
5) I want to learn more about dietary intolerances, mostly because of my lactose intolerance, and also because I have friends who have Celiac disease.
1. As a newly minted Second Semester Senior™, I am bound to suffer from the plaguing disease currently crippling the class of 2017: Senioritis. I will not let my diagnosis detract from my academic successes; I will finish the year with no grades lower than a B-. I will do so by maintaining the amount I study for tests, and continuing to attend classes. By allowing myself some Bs, I can regain lost sleep time from 3 1/2 stressful years and relax more before I leave for college.
2. I will fit into my NCL Presents dress by March 4, with no visible fat rolls or reliance on Spanx.
I will do this by consistently going to the gym, at least 3 days a week in addition to being more active while I teach dance classes. This will knock 2 birds out with 1 stone, allowing my students to have a more engaged and fun instructor while I get in shape myself. I will practice my dance solos more, so I can win first overall at competitions and get more confidence about myself. I will eat healthier, and stop taking late night Yogurtland runs. I will enlist others to help me keep my goals and have a selection of gym-buddies to accompany me on my workouts, making it a little more fun. Although weight shouldn't be the driving factor, I want to lose at least 7 pounds, hopefully more.
