Friday, May 18, 2012

Semester Final

    As i contemplate and reflect on the vastness of the things I have learned this year in this class I think of some of the major systems that keep our bodies functioning as a whole. I think of systems such as the circulatory system, the digestive system, nervous system, and the reproductive system all of which keep our species as a whole alive, happy, and moving forward.
    The circulatory system, keeps blood and oxygen running through our bodies. The heart pumps out some 5.6 liters of blood into the veins and arteries to be carried throughout our bodies. Through our veins and arteries blood passes nutrients, such as amino acids and electrolytes, gases, hormones,  etc. to and from cells throughout the body to help fight off diseases, stabilize body temp. and to help maintain homeostasis. Blood is not  the only fluid that runs through our veins, lymph. Lymph is simply recycles blood plasma after is has been filtered from the blood cells and returned to lymphatic system. The blood, heart, and blood vessels make up the cardiovascular system, while the lymph, lymph nodes, and the lymphatic vessels make up the lymphatic system, and together they make up the circulatory system.
    Eating, swallowing, the breaking down of food, the absorption of its nutrients, and the excretion of its waste are all part of the digestive system. After we have chewed and swallowed our food it starts to travel past the pharynx, through the esophagus and right into the stomach. The stomach secretes a very potent acid that began breaking up the food into smaller particles, the stomach then begins to slowly empty it contents into the small intestines. The small intestines begin by removing all the nutrients it want from the broken down food and transports them throughout the body. After  what is left of what started out as food reached the end of the small intestines it passes into the large intestine or ascending colon. The ascending colon pushes the waste upward toward the Transverse colon all while sucking out any nutrients the small intestine may have missed. Forming feces by sucking out the water through bacteria and fermentation the transverse colon pushes the feces onto the descending colon. Holding the feces until the body can have a bowel movement and push the feces out through the anus the descending colon is just one more step towards excretion
    Controlling every movement your body make both voluntary and involuntary the nervous system is a vital part of the human body. This system is made up of the brain, spinal cord, and the over 7 trillion nerves throughout the entire body. Touching something or any other sensation of touch your body has started in your nerves. The nerves interpret touch, pain, etc. into electrical signals which are passed through the body and to the spinal cord. The spinal cord, which is a dorsal, fluid filled tube that has over 13,500,000 neurons or neves, transports the electrical signal up to the brain where it is integrated into feeling.
    The reproductive system is different in both man and woman. The male reproductive system mainly includes the testes and the penis, while the female reproductive system mainly includes the ovaries and the uterus. The testicles hang in the scrotum by the spermatic cord. They are outside the body because they need to be cooler than the temperature inside the body, in order to make sperm. The testes also produce hormones to help keep the body working and create new life. The penises function in the reproductive system is transport the sperm to the ovaries or eggs in the female body. The ovaries are a set of glands that hold the eggs and produce estrogen. The uterus is the main holding place for the fetus while it developes into a mature baby ready to be born.
    All of these individual system work together to make us healthy and able to reproduce and make more of our species to continue on the intellectual legacy of the human race. Although i will miss this class im happy to say that i've learned alot of things and had fun doing it. I'm ready to move on and use this information for the better when i go to college and get my nursing degree.

Wednesday, May 16, 2012

2012 Final

Well, where do I even begin? This semester in Biology, I have honestly learned A LOT! I am going to explain 4 body systems that we learned about in class this semester in great detail, and I hope you enjoy!

First of all, i'm going to start out with the Muscular System! We have learned about the muscular system a lot this semester, and it is one of the few that I can explain well. The muscular system is made up of tissues that work with the skeletal system to control movement of the body. Some muscles, are voluntary, meaning that you decide when to move them. Other muscles, like the ones in your stomach, heart, intestines and other organs, are involuntary. This means that they are controlled automatically by the nervous system and hormones and you often don't even realize they're at work!

Secondly, is the Immune System. The immune system is our body's defense system against infections and diseases. Organs, tissues, cells, and cell products work together to respond to dangerous organisms (like viruses or bacteria) and substances that may enter the body from the environment. There are three types of response systems in the immune system. The anatomic response, inflammatory response, and the immune response. The anatomic response physically prevents threatening substances from entering your body. Examples of the anatomic system include the mucous membranes and the skin. The inflammatory system works by excreting the invaders from your body. Sneezing, runny noses, and fever are examples of the inflammatory system at work. When the inflammatory response fails, the immune response goes to work. This is the central part of the immune system and is made up of white blood cells, which fight off infection by gobbling up antigens. 

Then, is the Circulatory system. The circulatory system is the body's transport system. It is made up of a group of organs that transport blood throughout the body. The heart pumps the blood and the arteries and veins transport it. Oxygen-rich blood leaves the left side of the heart and enters the biggest artery, called the aorta. The aorta branches into smaller arteries, which then branch into even smaller vessels that travel all over the body. When blood enters the smallest blood vessels, which are called capillaries, and are found in body tissue, it gives nutrients and oxygen to the cells and takes in carbon dioxide, water, and waste. The blood, which no longer contains oxygen and nutrients, then goes back to the heart through veins. Veins carry waste products away from cells and bring blood back to the heart , which pumps it to the lungs to pick up oxygen and eliminate waste carbon dioxide.

Finally, i'm going to explain the Digestive System. The digestive system is made up of organs that break down food into protein, vitamins, minerals, carbohydrates, and fats, which the body needs for energy, growth, and repair. After food is chewed and swallowed, it goes down the esophagus and enters the stomach, where it is further broken down by powerful stomach acids. From the stomach the food travels into the small intestine. This is where your food is broken down into nutrients that can enter the bloodstream through tiny hair-like projections. The excess food that the body doesn't need or can't digest is turned into waste and is eliminated from the body.

To conclude, I have explained the muscular system, the immune system, the circulatory system, and the digestive system! These are all things that we have learned in biology this semester. I have really enjoyed having class with Mrs. Dent, and i'm going to miss her! 

Tuesday, May 15, 2012

Semester Two Final

Marcus Lewis
May 15, 2012
Semester Two Final

    As our year comes to an end, all we can do is step back. And take a look at what we have learned this semester. For this I need to travel through the body and then to the outside world. My “bigger” assignments included things like the digestive system model, and various reports on the other systems of the body; i.e Circulatory System, Nervous System, Respiratory System, ect.

    Firstly, I would like to go over one of our more recent assignments, the Digestive system. The digestive system provides the body's means of processing food and transforming nutrients into energy. The digestive system consists of the - buccal cavity, esophagus, stomach, small intestine, large intestine ending in the rectum and anus. I don’t believe that the system has a most important organ, because they are all necessary in order to make digestion possible. Granted for the system there are more organs, I summed it up due to length and time.

    Secondly, The cardiovascular system comprises the heart, veins, arteries and capillaries. The primary function of the heart is to circulate the blood, and through the blood, oxygen and vital minerals are transferred to the tissues and organs that comprise the body. The left side of the main organ (left ventricle and left atrium) is responsible for pumping blood to all parts of the body, while the right side (right ventricle and right atrium) pumps only to the lungs for re-oxygenation of the blood. And this time there is only one organ so I am able to choose the heart itself for the most important organ.

    Next, I want to talk about the central nervous system of vertebrates (such as humans) which contains the brain, spinal cord, and retina.  The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity for all parts of the body. Obviously the most important part of this system is the brain. For without it, you are not able to do any process.

    Lastly, the Skeletal System or the musculo-skeletal system. The musculo-skeletal system provides form, support, stability, and movement to the body. The Skeletal System serves as a framework for tissues and organs to attach themselves to. This system acts as a protective structure for vital organs. Major examples of this are the brain being protected by the skull and the lungs being protected by the rib cage. There are yet again no “most important” organs.

    These systems are just a few of the systems in the body which make us work to the extent it does. When all of the systems are brought together we are in homeostasis or equilibrium. They function together in order to maintain the lives we live.

2nd Semester Final

For your 2nd Semester Final, you will be writing a reflective paper over what you have learned in class.  You are to explain about 4 body systems of your choice, the main organs for each system and functions of each organ, and the function(s) of each system. Include an introductory paragraph (what you are going to write about), the body of the paper (one paragraph per each system), and a conclusion paragraph (a summary of your paper and how all the systems work together in your body to maintain homeostasis). Use proper grammar and punctuation. You may write the paper in Google docs and post the link on this blog.