Wellness Day Presentation: Stretching

Because we are both athletes involved in multiple sports throughout the year, Maxine and I chose to explore Warm Up and Cool Down Stretches for our wellness day presentation. I'm on the Varsity tennis team for SHS and as the season continued, we became lazy and stopped warming up and stretching before practicing. As a result, many people on the team started getting injured - spraining their ankles and getting tennis elbow. I wanted to explore why this was and how not stretching played a role in the injuries. Maxine had some similar experiences with her softball team, which is why we chose this topic. We began our project by asking classmates to post a couple sentences on the canvas discussion board about why certain stretches/exercises are used to warm up for one sport while different ones are used for another sport? We also asked classmates to write about how the stretches used to warm up for a particular sport help to warm up for that sport. 

Most people posted that stretching prepares the muscles that are used in the activity, so people who play upper body intensive sports tend to stretch out the arms and shoulders more, while those who play lower body intensive sports tend to stretch out the legs. For example, basketball players stretch out their legs and arms before playing, gymnasts do toe touches to improve their flexibility, and runners warm up with a light jog so not to run with cold muscles and get injured. Warming up before a sport is extremely important because it increases a body's internal temperature and stretches out the muscles around joints, making one less prone to injury. This increase in body temperature is crucial as it makes it easier for the lungs to gather oxygen, lowers the rate of metabolic reactions, increases the blood flow to muscles, reduces muscle viscosity, and increases nerve impulses. 

There are four main kinds of stretching: ballistic, static, dynamic, and proprioceptive neuromuscular facilitation. Ballistic movements involve repetitive bouncing movements, static movements stretch the muscles to the point of slight discomfort and is held for long periods of time. Dynamic movements challenge the muscles but in a comfortable range. Lastly, proprioceptive neuromuscular facilitation uses alternating contractions of the muscles. The stretches in each of these categories are separated even further into passive stretches, both of which are equally beneficial to the warm up process. 

From this project, I learned the importance of stretching and especially, how that warms up one's body temperature before doing strenuous physical activity. This topic is extremely important for health and wellness because without stretching, athletes would be more likely to get injured if they play a sport when their muscles are cold. On a scale of 1 to 10 for this project, I would definitely give myself a 9.5-10. Maxine and I put a lot of thought and effort into this project and tried our best to make it personal by reflecting on our own experiences. Maxine and I worked really well together as a team; we worked on the presentation together, had a video chat to go over the details of the presentation, and really thought through what information we wanted to go over with the class. I'm really proud of the presentation we made and will start thinking twice before I play tennis or go running without stretching and warming up.

For more details about this topic, see the powerpoint presentation we used here.

Unit 4 Reflection

This unit focused on the integumentary system. We explored the various layers of the skin (which are shown and labelled in the diagram below) and the purposes that the skin serves, for example, maintaining homeostasis and protecting the body. We also discussed how accessory organs like cutaneous glands, hair, and nails are formed and how they all work together with the skin to protect our bodies. 

We also touched on the Immune System, which consists of many different factors varying from nonspecific to specific that work together to defend the body against pathogens. The human body's first line of defense against invaders is non-specific resistance, which mainly involves the skin and mucous membranes, but also includes the epiglottis, urine flow, defecation and vomiting, tears, and saliva. Various chemical methods of nonspecific resistance like sebum, perspiration, lysozyme, and gastric juice work alongside the skin and mucous membranes to protect the body. If the pathogens somehow evade this first line of defense, eosinophils, basophils, neutrophils, and macrophages, which make up the second line of defense, work to inhibit the pathogens. Both the first and second lines of defenses are non-specific and will attack all pathogens. If the pathogen still manages to get by these two lines, the third line of defense - the specific response - will take place with the help of lymphocytes that differentiate into B cells and T cells and react to a particular antigen (a part of a pathogen). B cells and the antibodies they produce go on to neutralize pathogens or trigger complement proteins to cause cell lysis or attract phagocytes that take in the pathogen. T cells, on the other hand, release toxic substances that directly trigger apoptosis (programmed cell death). A comparison of how B cells and T cells work to defend the body against pathogens is depicted in the image below. We also discussed how benign and malignant cancers come about and can result from genetic and environmental factors. 

I almost fully understood most of this unit as it was a reinforcement of the most recent unit in AP Biology. I'm still a little bit confused as to how tumors arise and how they manage to evade the three lines of defense in our immune response. I still wonder as to how the glands in the integumentary system work and how nerve fibers get signals to the brain when we touch something and what, if any, role does the tactile corpuscle play in this process.

This unit solidified what I've learned about myself and my studying habits all through high school: I most definitely am a visual and verbal learner. As I was reading the textbook and filling out the reading guides for this unit, I found myself constantly drawing and labelling diagrams of the layers of the epidermis, the different types of white blood cells, and how T cells and B cells reacted differently when they encountered a pathogen. I've learned that diagrams really help me understand what we are learning about by making the material more tangible and "real" rather than theoretical. It really helps me to relate concepts we learn in class to everyday life; for example, using a hypothetical scenario of someone getting the flu or cancer and talking through or drawing out what that would potentially look like in the person's body on a cellular level. I think this is one of my major strengths, especially when it comes to science classes like biology and anatomy, as much of what we learn can be drawn or mapped out, making it easier to understand the bigger picture. A major weakness of mine is definitely memorizing specific details and applying them to that big picture, but I think my strength of visualizing and drawing out diagrams really helps me remedy this weakness. 

According to the VARK Questionnaire, I have a multimodal learning preference, meaning using visual aids, diagrams, and writing things down generally helps me learn. My scores from the VARK Questionnaire were visual: 9, aural: 8, read/write: 9, and kinesthetic: 11. I've been experimenting with studying strategies in some of my other classes and I think I agree. When studying for AP Biology, for example, I take notes from the textbook and then add in details from class lectures and try to incorporate diagrams or flowcharts to make sense of what the chapter discussed. The results from the VARK Questionnaire are generally what I thought they would be because I prefer using spatial diagrams and images, words (both written and spoken), and using my body, hands, and sense of touch to help me learn. I will definitely incorporate these techniques when studying for the upcoming Unit 4 Test, by actively studying: drawing out diagrams, taking notes from the textbook by hand, and maybe explaining the unit to a friend or classmate verbally to help me make sense of all the information.

Unit 3 Reflection

For the first half of this Unit we discussed the structure of the human heart (including the layers of the heart wall and the 4 chambers of the heart), the function of valves, the cardiac cycle, the circulatory system and its components, blood pressure, the different types of blood vessels, the different types of blood cells, and heart attacks. For a more detailed discussion of these topics, please click here to view my Mid-Unit Summary. The second half of this unit, we discussed how problems in the circulatory system (as we went over in the Heart Chalk Walk Activity) can lead to various cardiovascular diseases, specifically heart attacks and strokes. As I already detailed how heart attacks occur in my mid-unit summary, in this blog-post I will focus on strokes (shown in the picture below) and the respiratory system. 

A stroke is a brain injury that occurs when the blood supply to part of the brain is interrupted by a blood clot (also known as an thrombus, if it's made in a blood vessel and stays there, or an embolus, if it forms in one part of the body and then travels to another). It is sometimes referred to as a "brain attack," as it is essentially the same as a heart attack, except that it occurs in the brain. There are two main types of strokes: ischemic strokes and hemorrhagic strokes. An ischemic stroke occurs when an artery that supplies blood to the brain is blocked - a condition often caused by atherosclerosis. The picture below shows how in an ischemic stroke, a blood clot (in this case, an embolus) formed in the heart during atrial fibrillation can travel through the aorta, common carotid artery, and internal carotid artery, settle in a branch of the internal carotid artery, and stop blood flow. A hemorrhagic stroke, on the other hand, occurs when an artery taking blood to the brain bursts, which can be caused by high blood pressure or excess cholesterol, and blood leaks out of the blood vessel and into the brain. The brain tissue that had its blood supply cut off by the stroke dies and other parts of the brain must be trained to take over the functions that the dead tissue was responsible for (also shown in the diagram below). A transient ischemic attack (or TIA) is a "warning stroke" that only lasts a couple minutes, but foreshadows that a larger stroke is probably in the near future. When someone is having a stroke, the signs to check if he or she is really having a stroke and to minimize the effects of the stroke are to check the acronym FAST - Face (ask the person to smile), Arms (ask the person to lift up both of their arms), Speech (ask the person a question and see if they can respond properly), and record the Time since their symptoms (this will make it much easier for doctors to determine the proper course of treatment). Often times, doctors use the tissue plasminogen activator (tPA) to bust the clot formed, stent insertion to open up the artery, or MERCI to retrieve the clot via a "corkscrew" method.

Cardiovascular health is extremely important in order for blood to consistently and properly flow throughout your body. Cardiovascular diseases like heart attacks and strokes hinder the flow of blood and are generally caused by atherosclerosis of the coronary arteries. Atherosclerosis is chronic inflammation caused by the excess consumption of sugars, polyunsaturated fats, or Omega-6, and it can severely damage the blood vessels. Other factors that can lead to cardiovascular disease are lack of exercise, being overweight, smoking, diabetes, metabolic syndromes, high blood pressure (caused by atherosclerosis), and high cholesterol. Thus, to promote cardiovascular health and reduce the chances of cardiovascular disease, one should try to control their blood pressure and cholesterol, stop smoking, eat a healthy diet, consume alcohol in moderation, control weight and diabetes, manage stress, and be aware of family genetic history. I still wonder about the role that genetic history plays in our cardiovascular health: if all of my grandparents and many of my uncles have had diabetes or cardiovascular diseases, what are the chances that I will get it too? In addition, how do the lungs of the respiratory system work with the circulatory system to oxygenate blood before returning it to the heart?

In addition, we discussed how the respiratory system works in conjunction with our circulatory system by oxygenating the blood that the circulatory system then pumps throughout the body. The main functions of the respiratory system are to deliver oxygen, remove carbon dioxide, filter the air we breath in, and regulate the pH of the blood. The respiratory involves many organs that work together. The nose (nasal cavity) is a large open chamber lined with mucus that contains the sinuses. The pharynx (throat) also lined with a mucous membrane is a passageway for food and air that sends air to the larynx and food to the esophagus. The tonsils, which are also located in the pharynx, trap bacteria from the air we breathe in. The larynx (voice box) is made of 9 cartilage rings, contains our vocal chords, and contains a flap called the epiglottis which directs food into the esophagus and keeps food out of the lungs. The trachea (wind pipe) is an organ made of cartilage and lined with a mucous membrane that is hard in the front and soft in the back to allow the esophagus to expand when a person swallows. The lungs (air sacs) are surrounded by a pleural membrane and contain a bronchiole tree and an alveolar sac, which is very thin and easily damaged but is responsible for gas exchange in the capillaries. The image below shows how these organs function together to help us breathe:

We also did a sheep heart dissection towards the end of this unit that helped us visualize the different parts of the heart by identifying them on a real heart. It made me realize that a diagram of the heart is a simplified representation of the heart. Many of the structures in the heart are much harder to identify in a real heart, but are generally in the same locations that diagrams show them in, which was pretty amazing to see. Click here to read my previous blog post about our Sheep Heart Dissection. 

From this Unit, I realized how much of a visual learner I am. The various heart diagrams at the end of the heart dissection packet, diagrams like the ones I have inserted in my blog posts, and the sheep heart dissection all helped me visualize what we were learning much better - it made these cardiovascular diseases more relatable rather than just theoretical/textbook knowledge. I realized that these diseases are real and happening to people every single day, making the material more interesting to learn due to its relevancy. It also made me realize how much these diseases can affect me in the future, which is why I need to be more careful with my eating and exercise habits to ensure I don't get diabetes or cardiovascular diseases early in life. I also learned that I need to spend more time memorizing details that cannot be visualized, as it has always been hard for me to memorize facts. I think I'm definitely a better student after this unit, as I learned the importance of collaboration and working together, especially when it comes to labs like the dissection. In regards to the Unit 2 health goals, I think I'm doing much better with exercise as I have tennis practice everyday and have started running on the weekends. In addition, I've been more conscious of my eating and have been trying to consistently eat 3 meals a day. Lastly, I'm still pretty stressed out and sleep-deprived due to my class load and college applications, but am working on my time management so I can finish my work faster and sleep earlier. And if I find myself feeling too tired at the end of a day, I take a nap before starting my work. Though I still have a long way to go before my health is where I want it to be, I think I've made a lot of progress already and just need to work on it more.

Sheep Heart Dissection

Here is the link to our Sheep Heart Dissection Video Tutorial

Lab Questions: 

1. The pericardium consists of an outer fibrous layer and an inner double layer of serous membrane. It's purpose is to surround the heart, protect it, and help keep it in place as it's beating.

2. The veins have thinner walls than the arteries but store most of the blood volume in our bodies. They are responsible for carrying blood back to the heart and they have valves that ensure the blood flows in one direction. On the other hand, arteries are elastic and contractile blood vessels that have much thicker walls as they carry blood away from the heart and to the rest of the body.

3. The auricles, which felt rough when we touched them, are elastic ear-shaped appendages that are external parts of the atria and increase the blood capacity of the heart's atria, allowing the atria to expand and hold a greater volume of blood. 

4. The atria have auricles on the outside and are much smaller in size than the ventricles, which appear to be completely covered in fat. 

5. The coronary sinus is a wide channel that collect deoxygenated blood from the coronary veins and empties into the right atrium of the heart. The inferior vena cava is a large vein that brings deoxygenated blood from the lower body to the right atrium of the heart. Lastly, the tricuspid valve, ensures that blood flowing from the right atrium to the right ventricle flows in one direction with no back flow. 

6. Picture of the tricuspid valve, including the chordae tendinae and the papillary muscle:

7. When the right ventricle contracts, the pressure of the blood in the ventricle increases and the blood pushes up against the tricuspid valve, which keeps the blood from flowing back into the right atrium. The chordae tendinae attach to papillary muscles that pull the chordae tendinae to open and shut the valve.

8. The bicuspid valve lies between the left atrium and left ventricle and, like the tricuspid valve, it ensures that the blood flows in one direction.

9. The semilunar valves keep blood in the arteries from re-entering the ventricles of the heart during ventricular diastole and ensures that blood is consistently traveling into the arteries and to the rest of the body. There are two types of semilunar valves: the aortic semilunar valve, which is situated where the left ventricle empties into the aorta, and the pulmonary semilunar valve, which lies at the opening where the pulmonary trunk leaves the right ventricle. 

10. Valvular heart disease:

a) An abnormal amount of blood is flowing to the feet and ankles in an uncontrolled manner because the ventricles are unable to pump blood up against the flow of gravity, and thus, back flow occurs.

b) If valve disease were to occur on the left side of the heart, an insufficient amount of blood would be pumped throughout the body, causing swelling. 

11. The coronary arteries supply blood to the heart muscles. The aortic semilunar valve keeps blood in the arteries from re-entering the ventricles. The chordae tendinae are stringy structures that attach the cusps of valves to papillary muscles. Lastly, the papillary muscles provide the "muscle power" that pull the chordae tendinae to open and shut the valve.

12. The right side of the heart has thinner walls than the left side of the heart and mainly deals with deoxygenated blood. Deoxygenated blood enters the right atrium through the inferior and superior vena cavas. The blood then travels through the tricuspid valve and into the right ventricle, which pumps the blood through the pulmonary semilunar valve and into pulmonary veins. The pulmonary veins then take that blood to the left and right lungs to be oxygenated. The left side of the heart, on the other hand, has thicker walls because it is responsible for pumping blood to the entire body and it mainly deals with oxygenated blood. Oxygenated blood from the lungs enters the left atrium via pulmonary arteries. The blood is then pumped through the bicuspid valve and into the left ventricle. The left ventricle (the largest chamber of the heart) pumps the blood through the aortic semilunar valve and into the descending aorta, which takes oxygenated blood to the lower body, and the ascending aorta (aortic arch), which branches into three other arteries that all take blood to the upper body. 

13. Drawing of the interior of the cross section:

Mid-Unit Summary: The Heart

The human heart is about the size of a first and weighs less than a pound. It is located in a cavity of the thorax called the mediastinum and is covered by the pericardium, a double sac of membranes that releases fluids to lubricate the heart and reduce friction. The three layers of the heart (as shown in the image below) are the epicardium which is the visceral pericardium, the myocardium which is the contractile part of the heart, and the endocardium which lines the chambers of the heart. 

The heart has four chambers that help regulate the blood: the right and left atria, which receive blood, and the right and left ventricles, which discharge blood. The valves of the heart - labelled in the image below - keep blood moving in one direction and prevent the back flow of blood. When listening to a heart beat, the "lub" sound happens when the tricuspid valve (between the right atrium and right ventricle) and the bicuspid valve (between the left atrium and left ventricle) contract. The "dub" sound is heard when the aortic and pulmonary valves close as the heart relaxes. The nodal system of the heart is composed of the SA (sinoatrial) node which is found in the right atrium and the AV (artrioventricular) node which is found where the atria and ventricles meet. This nodal system is made up of special tissue that causes the heart to beat uniformly at about 75 beats per minute. The cardiac cycle is the heat's rotation between systole (contraction) and diastole (relaxation) of both the atria and both the ventricles that work together to push blood through the body. For more information on how blood is circulated through the chambers of the heart, see my previous blog post from our heart chalk walk activity here

The circulatory system is a fluid-filled network of vessels through which materials move between the environment and cells of a multicellular animal. It's major components are the heart which continuously circulates blood, the arteries which take blood away from the heart, the veins which bring blood back to the heart, and blood which is the fluid being circulated. The image below depicts the structural differences between arteries and veins. The specific parts of the circulatory system are pulmonary veins and arteries, the aortic arch and trunk, the common carotid artery, the renal vein and artery, and the mesenteric arteries. Some accessory organs that aid in the circulation of blood are the lungs, kidneys, small intestine, large intestine, liver, spleen, and bone marrow. Blood pressure is measured by the systolic pressure, which results from the contraction of the ventricles, and diastolic pressure from the relaxation of the heart. To learn more about blood pressure, see my last blog post from our blood pressure lab here

Many blood vessels work together to aid in the circulation of blood through the circulatory system as shown in the diagram above. Veins are thin vessels that carry blood from the tissues to the heart. Arteries are elastic and contractile vessels that carry blood away from the heart and to the tissues. Capillaries are tiny vessels that connect arterioles (small arteries) to venules (small veins). Blood - the main material pumped through the circulatory system - has three components (depicted below): red blood cells, a buffy coat made up of white blood cells and platelets, and plasma. Blood's main functions are transportation, regulation, and protection. Different types of white blood cells in peripheral blood include neutrophils, basophils, eosinophils, lymphocytes, and monocytes, each of which has different responsibilities in the body. 

One of the main cardiovascular diseases is a heart attack, which is caused when blood supply to the myocardium is severely reduced or blocked and is usually due to atherosclerosis. Atherosclerosis is a disease that occurs when fatty material deposits on the inside of blood vessels, making it harder for blood to flow - the chronic inflammation is generally caused by excess polyunsaturated fats, omega-6, and damaged blood vessels that cause LDL (bad cholesterol) to stick to damaged cells causing plaque to develop, as shown in the image below. Another cardiovascular injury, an aneurysm occurs when a thin weakened portion of the blood vessel wall droops, and they are life threatening, especially if they burst. Cholesterol, a cause of atherosclerosis, comes in two types: LDL which sticks to arteries and HDL which cleans up the build up of LDL in arteries. A major effect of a heart attack which is often confused with a heart attack is cardiac arrest, which occurs when the heart stops beating entirely. Signs of a heart attack include chest pain/pressure, arm pain, nausea, shortness of breath, and pale/sweaty skin. Methods to diagnose a cardiovascular disease include an angiogram, an echocardiogram, an electrocardiogram (EKG/ECG), a stress test, or nuclear scanning. Factors that increase the risk of a heart attack are a lack of exercise, obesity, smoking, diabetes, high blood pressure, and high cholesterol. Thus, it's important to maintain good health to prevent a heart attack from occurring.

Blood Pressure Lab

When taking someone's blood pressure, the first number is the systolic blood pressure the second is the diastolic blood pressure. The systolic blood pressure measures the pressure of a person's blood when the ventricles of the heart contract and blood moves out of the heart. The diastolic pressure measures the pressure in the heart when the heart relaxes. Doctors use a stethoscope to measure a patient's heart rate and a sphygmomanometer to measure a patient's blood pressure. Sphygmomanometers measure a person's blood pressure by squeezing a person's arm and listening to the heart beat when the pressure is released. You can also use your thumb to read your pulse from your carotid or radial artery; however, it is not a reliable reading because your thumb has a pulse of it's own. When using a sphygmomanometer to take blood pressure, be sure that it is free of air and double check that the valve is tightly shut. Put the band around the person's upper arm and place a stethoscope underneath. Using the pump, add pressure to the sphygmomanometer to add pressure until the meter reads 150 mmHg. Once you've reached this pressure on the valve, open the valve to slowly release air. The recorder should listen for the heartbeat and mark the pressure at which they hear the first heartbeat. Likewise, they should record the pressure when they can no longer hear a heartbeat. The number recorded when the heartbeat is first heard is the systolic blood pressure and the number recorded when the heartbeat is no longer heard is the diastolic blood pressure. For this lab, I partnered with Michelle Koo and we measured each other's blood pressure and heart rate using the method described above. The results we got are recorded in the table below.

Heart Chalk Walk Reflection

When blood is traveling through the circulatory system, deoxygenated blood from the body enters the heart through the superior or inferior vena cava and empties into the right atrium. The deoxygenated blood then flows through the tricuspid valve and into the right ventricle. Once the right ventricle is filled, the blood is pumped through the pulmonary valve and into the pulmonary artery, which takes the blood to the lungs to be oxygenated. Once the blood has been oxygenated by the lungs, it returns to the heart through the pulmonary veins. This now oxygenated blood flows through the pulmonary veins and enters the left atrium, after which the blood is pushed through the bicuspid valve and into the left ventricle. Once the left ventricle is filled, the blood is pumped through the aortic valve and into the aorta, which takes the oxygenated blood to different parts of the body.

Unit 2 Reflection: Health

Health is a measure of our body's efficiency and overall well-being. The 5 aspects of life that contribute to a healthy lifestyle are stress, exercise, nutrition, sleep, and social interaction. A good analogy to explain health is that the 5 aspects listed are like 5 pillars of health. I learned in this unit how anytime one pillar is lacking, the others make up for it to ensure that the health of the body "stays standing." Ideally, if a person takes care of all 5 pillars, their overall well-being will be in optimal condition, which is why people should be sure to pay attention to all of the pillars. One very important aspect of being healthy is having healthy hormones - the "big 4" are insulin, leptin, glucagon, and cortisol. These hormones work together to maintain optimal glucose levels inside the body and control our biological cycles. The four keys to maintaining a healthy life style, even when you follow all of the suggestions from doctors and scientists, are adequacy, variety, moderation, and balance in everything you do. Don't stress, exercise, eat, sleep, or socialize too much or too little - do them all in moderation. The first pillar of health, stress, has three main stages: alarm, resistance, and exhaustion. The alarm phase refers to when a person's body pumps adrenaline to trigger the "fight or flight" response in reaction to some immediate stimulus. The second phase, resistance, refers to the body's reaction to long term stress, which may result in damage to the body. The last phase of stress, exhaustion, is the most extreme phase and can eventually even lead to death. Another pillar of health - exercise - deals with the intensity of workouts involving muscle-strengthening, bone-strengthening, aerobic, and flexibility-improving exercises. To uphold the third pillar, nutrition, it is important to maintain a balanced diet filled with vitamins and minerals. It's also important to get a sufficient amount of sleep during the night, especially REM sleep, because that is actually when your brain is most active and it is the time when your body repairs itself. Lastly, to maintain the fifth and final pillar, one must be socially active. As demonstrated by the Social Readings we discussed, being socially active can prevent many future diseases and contribute to a person's overall good health.

From the activities in this unit, I learned that I am overall pretty healthy. I need to, however, start eating healthier, sleep longer, and learn to manage my stress better. In order to do this, I will start paying attention to the nutrition facts and ingredients in the foods I eat, I will try to eat a more balanced diet, I will try to start sleeping earlier and nap when I'm tired, and I will work on my time management to reduce my stress. A healthy life is important to me because maintaining all the pillars of life will help me live longer and better and stay away from diseases like diabetes and heart problems. To promote health and wellness on campus, teachers should find a way to coordinate when big tests like Midterms and Projects in other classes are and do their best to make sure their tests and projects do not overlap with those in other classes. In addition, students should learn to procrastinate less. By managing their time better, they will not only be able to sleep earlier, but also reduce their stress. My biggest problem, by far, is definitely sleep. Here is a Tedtalk that I came across by Arianna Huffington entitled, "How to succeed? Get more sleep" that discusses just this - why we should sleep longer rather than brag about our sleep deficit: https://www.ted.com/talks/arianna_huffington_how_to_succeed_get_more_sleep. 

Throughout this unit, I understood most of the "big picture" concepts thoroughly, but missed a couple days of class due to tennis matches. This put me behind in some of the labs and lectures, making it harder for me to see the bigger picture during the following class when we moved on to a new lecture. I still don't fully understand how the hormones like leptin and cortisol function in our bodies as they have many factors influencing them and have complex cycles. Next unit, I will try to miss less classes, stay organized with the lecture notes and paste them into my notebook as soon as I get home, and get more sleep at night so I will be more attentive in class.

Sleep Diary

This assignment to keep a sleep diary made me extremely aware of my poor sleeping habits. According to my sleep diary, I get an average of 6.36 hours of sleep per night as opposed to the 9-10 hours of sleep that is recommended for teenagers. This explains why I often get extremely tired by the early afternoon, generally take a nap in the evening, and then can stay up late at night. I noticed during this exercise that I often couldn't concentrate as well during class in the morning as I could when I was doing my homework late at night. In addition, my parents complained a couple times this weekend that I was easily irritable which, as we learned in class, happens to be one of the effects of sleep deprivation. It would also explain why I've gotten sick a couple times this year already, as another effect of sleep deprivation is reduced immunity. From this exercise, I learned that I really need to start sleeping earlier and making sure I get at least 8-9 hours of sleep to ensure I don't throw off the secretion cycles of cortisol and melatonin in my body and to ensure I can be more awake and concentrated in class. This is especially important because I drive to school every morning and we learned from the reading, "The Promise of Sleep," how incredibly fast you can fall asleep when you're tired, without even knowing it.

One Week Nutrition Analysis

From September 18th to September 22nd, I recorded the foods I ate throughout the day and the nutrients in those foods. At the end, I also calculated how much more or how much less of each nutrient/ingredient I was eating than I should have been. My calculations strangely showed that, overall, I consume too much, as I consumed over the recommended amount for every component of food that we analyzed. 

One major element of my diet that I now know I need to improve on is my sodium intake as I was 383% over my recommended amount. Recently, I noticed that I have been eating out a lot - for example, the foods in my diet that had the highest amount of sodium were a pizza from Pizza My Heart, a Razzmatazz smoothie from Jamba Juice (twice), and chicken noodle soup from Safeway. I partially blame this on how stressed I was last week as I had a test in every class and hence, I didn't have time to make lunch for myself in the morning and so generally went off campus for lunch. I think if I started limiting the amount of food I eat out and start eating homemade food more often, I could reduce the amount of sodium I eat. 

One other area of my diet that needs improvement is my protein intake. According to my calculations, I consume about 355% more protein than recommended. Throughout the week, I had some sort of meat 3/5 days and consumed meat during two meals on those 3 days. I think this significantly contributed to the high amount of protein in my diet. If I consume less meat, I can reduce my protein intake and bring it closer to the recommended amount.

Though I initially thought I didn't eat as much as I should, my calculations show that I need to start cutting back on the number of calories I eat because I consumed approximately 170% calories above my recommended amount. One way to improve the amount of calories I've been eating is to reduce my carbohydrate intake. Most days, I either ate cinnamon buns, a sandwich, or a bagel at some point during the day. All of these foods contain lots of carbohydrates and contributed heavily to my heavy calorie intake. If I cut down on the amount of carbohydrate-heavy foods I eat, I could reduce the number of calories I've been consuming by half. Another major reason for why my calorie intake is so great is once again, how much I have been eating out. I think I need to start eating lighter meals and instead snack throughout the day. I have a general tendency to not eat anything for hours and then eat too much during meals. Another way to potentially cut down on my calories would be to work out more - although I do attend tennis practice, it's not too grueling and I could probably fit in time to go to the weight room after practice or go for a run, which would help me burn more calories. In addition to reducing my food consumption, this would lead to a healthier lifestyle.

In order to improve my diet, I need to start eating more fruits, vegetables, and dairy products, and I need to start cutting down on the amount of calories, protein, and sodium I consume. I think I need to also be more aware of what I buy from the supermarket - for example, trying to avoid products with hydrogenated oil or high fructose corn syrup, as we learned in class. One possible reason that my data showed I was above the recommended amount is because I may not have given myself enough credit for how much physical exercise I do when I was calculating my recommended amounts When I'm stressed out, I tend to "stress-eat" and eat a lot of carbohydrates In addition, I tend to eat while watching TV or watching Netflix, so I don't realize how much I'm eating. In order to improve my diet and live a more healthy lifestyle, I think I need to start being more aware of what I'm eating and what the nutrition facts are. I will also start bringing food from home instead of eating out at lunch all the time. I think these changes will greatly help me bring my food intake closer to the recommended levels and help me eat healthier.

Bibliography:

Chex mix label

What is Health?

Good health is very important to me. It is a state of being in which a person's physical, mental, and social well-being keep them from illness and disease. In order to have good health, it is important to understand all 5 pillars of health - nutrition, exercise, sleep, stress, and social interaction - and how they work together to help a person carry out normal body functions. I think that nutrition and exercise are the two pillars that I am strongest at. Failure to consume healthy foods and reliance on junk food doesn't allow your body to acquire the nutrition it needs to help you grow and lead a healthy lifestyle, and it increases your chances of growing obese and developing diabetes. Most days, my mom makes dinner at home and makes an effort to use good, fresh ingredients to ensure I have a diet with a balanced amount of protein, vegetables, and carbohydrates. In addition, I've always been a very active child, involved in sports like soccer, tennis, and track and field, and so, I do a lot of exercise. On the other hand, I think the two pillars that I need the most improvement on are stress and sleep. Because I took on a heavy workload junior year and had a lot going on at home, I was constantly stressed out. This also took a toll on my sleeping patterns as I would be awake really late at night and essentially sleepwalk through the rest of the day. I want to learn how to manage my stress better so that I can sleep better, and in turn, maintain all the pillars of health in order to carry on a healthier lifestyle.

Oligodendrocytes

The picture above shows the location of oligodendrocytes in relationship to neurons (yellow).

Oligodendrocytes are glial cells that are similar to astrocytes. They are support cells found in the spinal chord and brain, and their somata (cell body) can be about 12-14 micrometers in diameter. Their main job is to produce myelin which is made in both the central nervous system (CNS) and peripheral nervous system (PNS). However, oligodendrocytes are only responsible for myelin production in the CNS, while Schwann cells produce myelin in the PNS. The above picture shows the two different cells and where they are located. Myelin is very important in the CNS as it is a fatty substance that insulates and protects the gaps in the sheath of the neuron. If the axons in a neuron did not have myelin, the action potential or charge when an impulse moves along the axon would be continuous along the sheath, rather than just at the nodes of Ranvier.

Oligodendrocytes are generally circular in shape and are divided into three parts: the cell body, the cytoplasmic processes, and the myelin segments. The cell body is the main part of the oligodendrocyte and it contains the nucleus, which is generally dark and oval-shaped and has a cluster of chromatin inside. The cell body has the same organelles that are in all eukaryotic cells. The cell's processes are what form the myelin segments that cover the axons. Lastly, the myelin segments are circles around the axon that insulate the axon. There are two main types of oligodendrocytes: 1. satellite cells that are around neurons in gray matter, form the outer layer of the cerebrum, and maintain the ion balance in neurons and 2. myelin-producing cells in the white matter.

The following image illustrates the structure of an oligodendrocyte as described above:

Hana the Banana Lab

From the external findings on the left side, Hana has a laceration that is medial to her left ear and seems to have hit the left eye as well. The ending of the gash is 1 centimeter superior to Hana's mouth. Hana has a second gash on her left side which is inferior to her arm and medial to her back. It is 1 millimeter lateral to her midline. Observing from the right side, Hana has a deep cut that is distal to the elbow and cut off three of her fingers. She has another gash that is 1.5 centimeters medial to the right arm and is towards her anterior. She has a third gash that is 2 centimeters superior to her feet. The presence of 2 centimeters worth of puncture wounds and discoloration superior to her right ear is also suspicious. To open the ventral body cavity and expose the internal organs of Hana, a mid-sagittal cut was made so that the right and left internal organs could be examined - images before and after the opening of the ventral cavity are attached. From the right sagittal view, it was clear that the external gash on the upper right protruded into the body cavity. Hana's second gash is inferior to the pelvis and cuts through the body at an oblique angle. The left sagittal view of Hana exposed discoloration by the midline extending to the end of the body cavity. From this autopsy, it can be concluded that Hana the Banana was viciously attacked by Jason Voorhees from Friday the 13th who slashed at her multiple times with his machete. The severity of the wounds and the extreme loss of blood ultimately resulted in the patient's death.