Frog Dissection

Unlike most people, I found looking at a frog's insides quite "cool." Sure, while dissecting the frog I felt bad. I mean, it was a living creature. And yet, I had to take it apart. Before we started to dissect our frog, our teacher told us to get to know the frog. After taking some time to get to know our frog, we decided to name it Kermit (my teacher, "Very Original"). Later one, we discovered our frog was a girl. So we changed its name to Kermita.
The first thing my lab partners and I saw were the blood vessels. When we made the "doors" with the skin in the frog, my lab partner noticed the blood vessels right away. I had a hard time believing her. I always thought that the blood vessels sort of roamed around the body. I was wrong. When my teacher pointed the blood vessels out, I was extremely astonished. The blood vessels were kind of stuck onto the skin. It was almost as if the blood vessels were drawn onto to the skin.
Once we cut through the layers of muscles, we came to the organs. Remember when I said we discovered the frog was a girl, well this is how we knew. When we opened it up, the eggs were the first thing we saw. Because there were millions of them, they took up a huge portion of the frog. The eggs were small and black. To study the organs, we had to scoop out the eggs. This is when I started to feel bad about cutting open a frog. I was surprised that the eggs weren't protected by anything. In the human body, the eggs are in the ovaries and are the size of a cell. On the other hand, the eggs in the frog were visible to the naked eye. Seeing as most organisms exist to reproduce, you would think the reproductive organs and parts would be protected. The next thing we saw was really disgusting. They were these spaghetti shaped things in an orange and yellow color. I'm pretty sure you've already guessed it. They were the fat bodies. Luckily, Kermita wasn't fat, so there wasn't much fat to take out.
After we pulled out the fat, we were able to see the organs. Did you know that a frog has three livers? I didn't. I was flabbergasted when I saw the three livers. At first, I thought it was the lungs and the stomach. I was obviously wrong. The three livers are called the right lobe, the left anterior lobe, and the left posterior lobe. The liver's function is very important. It produces bile, a substance that breaks down the fats in the body. Underneath the livers, wass the gall bladder, the stomach, and the intestines. The function of the gall bladder is to store the bile the liver produces until it is needed. The function of the stomach I would think is quite obvious - it breaks down the food through mechanical and chemical digestion. The chemical digestion is when the hydrochloric acid and pepsin in the stomach break down the food. After the stomach, the food goes into the small intestine. The function of this organ is extremely important. It extracts all of the nutrients in the chyme. The large intestine is not at all like the large intestine in the human body. It looked a lot like the stomach. The large intestine seemed to be the same size as the stomach too. The difference is the function of the large intestine is to prepare wastes for elimination from the body.
We also saw the heart and lungs. The heart pumps the blood. It was white and it actually looked like a legitimate heart. Since it is a major organ, it is protected by the peritoneum (a spider web like membrane that covers the organs). Because there was no air in the lungs, they looked deflated. This is because the frog was preserved.

All in all, dissecting a frog was a fun learning experience. Frogs are interesting creatures and learning how their body works made them even better.

If you are interested in learning more about a frog's anatomy visit the website below:

http://frog.edschool.virginia.edu/Frog2/

My Picture Sources:

http://muppet.wikia.com/wiki/Kermit_the_Frog

http://www.e-tutor.com/et3/lessons/view/52133/print

http://www.scientificillustrator.com/illustration/amphibians/leopard_frog.html

Glogster

This is the link to my glog on the Circulatory System:

http://www.glogster.com/cocoapuffs321/the-circulatory-system/g-6lsvre7un0ips2hu54bo1a0

As the Stomach Churns

Day 1:

In Science class, we did a lab that showed how digestions occurs in the stomach. We used hydrochloric acid dilute, pepsin, water, and cubed egg whites. The hydrochloric acid dilute, pepsin, and water represented the chemicals in our stomach. The egg whites represented the food we are digesting. We had four test tubes that represented four different stomachs. In test tube A, we put the pepsin and three egg whites. Our test tube A had no immediate reaction. Then, we put water, pepsin, and three egg whites in test tube B. Test tube B did not have any immediate reaction other than the water going to the top and the pepsin sinking to the bottom. Next, we put hydrochloric acid dilute and three egg whites in test tube C. This test tube did not have any immediate reaction. Lastly, we put hydrochloric acid dilute, pepsin, and three egg whites in test tube D. This test tube also did not have any immediate reaction. After each test tube, we used litmus paper to test which test tubes were acidic. Test tube A and test tube B were not acidic because the blue litmus paper did not turn pink when it came in contact with the substances inside the test tubes. However, the blue litmus paper turned pink when it came in contact with the substances in test tubes C and D. This is because both of these test tube held hydrochloric acid dilute.

Day 2:

When we came back to science class today, we observed the test tubes again. In test tube A, the egg whites did not dissolve. Instead, the pepsin inside froze and hardened around the egg whites. The next test tube, test tube B, had some change. The pepsin dissolved into the water making it foggy. The egg whites seemed to have shrunk by the smallest amount. In test tube C, there was no reaction. The egg whites did not shrink. When we got to test tube D, we saw a significant change compared to the other test tubes. In our test tube, the egg whites shrunk and the piece were coming off from it. Lastly, we used the blue litmus paper. Again, test tubes A and B did not make the litmus paper turn pink. However, the substances inside test tubes C and D made the blue litmus paper pink. Looking at test tubes A and C, I can confirm that the pepsin and the hydrochloric acid dilute are not powerful by themselves. When they are combined, however, they can do much more. This is shown in test tube D. In this test tube, the hydrochloric acid dilute and the pepsin were combined. In just one day, you could a significant difference from the day before.

Chicken Wing Dissection

In class, we watched our teacher perform a chicken wing dissection. This was to show how the human arm worked. As she was dissecting, the first type of tissue we saw was the skin tissue. The skin is a type of epithelial tissue. This tissue was whitish-yellow and was bumpy. The skin was attached to the muscle tissue. Then, our teacher showed us the muscle tissues. The muscle was pink and smooth. The muscle attached to the bone. Before our teacher reached the bone, she showed us other types of tissue. We saw fat and ligaments. The fat was white and smooth. It is used as a cushion. Next, we saw the ligaments. The ligaments were white. This used to help move the muscle tissue. The fats and ligaments are attached to the muscle tissue. When our teacher reached the bones, we saw the cartilage. This connects to the bones and is used to help the bone move around. Without cartilage, our bodies would be stiff as rocks. The cartilage was also white. In the chicken wing, there are also nerve tissues. However, in the chicken wing our teacher dissected, we were not able to see the nerve. If it was there, it would have been attached to the muscles.

This lab was done to show how a human's arm works. Almost everything is the same. The skin is the first tissue. Then comes the muscle. After that the fats ligaments are shown. Lastly, you will see the bones and cartilage. Additionally, the way a chicken's wing works is similar to the way a human's arm works. In both organisms, the skin is the first layer. It is always used to protect what is on the inside. The muscles move the same too. They both need the ligaments to help. The fat is used to cushion in both organisms. Lastly, the cartilage helps the bones move in both organisms. Although, there are two things that are different. The first one is that the muscle proportions are different in the organisms. The last one is that chickens don't have phalanges (finger bones).

Diffusion Lab

To demonstrate how diffusion works in a cell, we did an experiment with iodine and starch. In the experiment, we put a spoonful of starch and a small amount of water into a plastic baggie. Then, we filled a beaker halfway up with water. Lastly, we poured some iodine into the beaker and placed the starch baggie into the beaker. To finish the experiment, we had to let the baggie sit in the beaker for at least fifteen minutes.

After fifteen minutes, the starch in the bag was supposed to turn purple. This is because of diffusion. Diffusion is the term used to describe the process of molecules moving form an area of high concentration to an area of low concentration. In the lab, the plastic baggie was selectively permeable. Selectively permeable means that only certain things can go in and out. Since the plastic baggie was selectively permeable, the iodine molecules were able to go through the bag and spread into the starch. Once starch and iodine mix, they become purple. This is supposed to happen. However, in our lab the iodine molecules were not small enough to go through the baggie.

This experiment is a demonstration of what happens to cells. The plastic baggie represents the cell membrane. The starch represents the cell and the iodine represents things outside the cell. Our cell membrane is selectively permeable. This way only certain things can go into and out of the cell. For example, the cell allows water to come in and allows waste product to go out. However, it doesn't allow the organelles to go out or waste to come in.

Picture Source:

http://missbzscience.wikispaces.com/4b)+Diffusion+%26+Osmosis

A Paralyzed Man Can Now Walk

After a brutal car accident in 2006, Rob Summer was paralyzed chest down. After the accident Summers was given two years of therapy to gain movement in his legs. After all this, he still wasn’t able to even move his toe.

Then, in 2009 Summers was given a surgery where the doctors placed a device that would electrically provoke the lower spine. The device is supposed to copy the signal that usually comes from the brain. Right when the indication is given to the spine, the patient tries to do something with his legs. In this case, he would attempt to stand up without help. When Summers wants to move his legs, the nerves in the spinal cord work to control the muscle movement. All of this happens without the brain’s contribution.

After a while, however, the brain was able to make some sort of connection with the legs. When Summers wants to move his legs or arms voluntarily, the brain actually gets an input. Researchers aren’t truly sure how this even happened. However, the believe that the electrical stimulation must of turned on the nerve circuits that weren’t damaged by the accident. Another theory they have is that the electrical stimulation created new connections with the injured nerves.

I find this article to be very interesting. It is definitely a medical breakthrough. The fact that a man who couldn’t even move a toe for four years can now walk, is truly amazing. Additionally, through this, scientist learned much more. They learned that even if you are totally paralyzed, there is still some nerve activity. This information is crucial to know if you are treating paralyzed patients. One day, everyone will be able to walk.

Source:

http://www.livescience.com/14245-paralyzed-man-spinal-cord-injury-walks-electrical-stimulation-therapy.html

A Possible New Lung Stem Cell

After a recent study, scientist may have found a stem cell in the human lung. The stem cell found was capable of making a large amount of the organ’s tissue. To find out if the cell is really a stem cell, scientists tested it out on mice. They punctured the lungs of twenty-nine mice. Then, they injected the six doses of twenty thousand cells into the mice. Within the next ten to fourteen days, the cells that were injected created new airways, blood vessels, and air sacs in all of the mice. This showed a huge difference. The stem cells produced millions of new cells in a very short time. With this new discovery, scientists may be able treat deadly lung diseases, such as emphysema. It may also be able to treat pulmonary hypertension, which is high blood pressure in lungs’ arteries. Another way stem cells could be used is to help the lung recover after lung cancer surgery. However, scientists are not sure on whether the lung stem cell could help with asthma.

I find this to be a remarkable discovery that will change the face of medicine. Finally, we may have found a cure for fatal diseases like emphysema. This disease kills thousands of people every year. To have a cure for it is amazing. Although scientists aren’t sure on what diseases it will cure, it is up to our generations to find out. The stem cell discovery shows that technology is drastically improving. With this discovery, emphysema and other lung diseases will soon be a joke.

Sources:

Article and Picture:

http://healthland.time.com/2011/05/13/scientists-identify-possible-human-lung-stem-cell/

One of a Kind Whale

A few countries in the world-such as Norway, Greenland, and Japan- still allow whaling. However, in Norway, when a whale is hunted and is used in a whale product, it has to be given a DNA analyses to determine if the product comes from a legal source. When a geneticist named Kevin Glover was looking at a whale DNA, he was shocked. This DNA showed proof of a hybrid. The whale was a cross between a Northern Minke and an Antarctic Minke.

The only time the whales can meet is wen they are migrating. Both of the whales go down south during winter. However, a Northern Minke and an Antarctic Minke live on separate Hemispheres. so the chance of them meeting is slim to none.

This discovery by Kevin Glover has changed science. It shows that these whales might be migrating at different time. When I learned that the whales migrate at different times, i was surprised that an offspring of a Northern Minke and an Antarctic Minke could be born. I believe that this whale mix is the beginning of a new species.

Article and Picture source:

http://news.nationalgeographic.com/news/2011/01/110125-whales-hybrids-antarctica-arctic-science-animals/

New way to Diet: Imaginary Food?

Recently, scientists dicovered a new way to diet. Most people believe that when you diet, you shoud not think of chocolate or any other unhealthy foods. Well for those people, science has proved you wrong. Through hours of studying, scientists have come up with the most unbleievable technique. If you imagine a specific food, you loose your interest in it, causing you to eat less of it. However, this technique only works with the specific food you are imagining. For instance, if you are imaginig chocolate, that won't stop you from scarfing down a family-sized bag of potato chips. Being exposed to food repeatedly is called habituation. This habituation gives a signal to your brain that gives you have the feeling of a full stomach. Therefore, you end up eating less of it.

I think this article is important because it shows a new way for people to eat healthy. Many people in the U.S. are obese. Being obese, gives you a higher chance of Type Two Diabetes, Heart Disease, and strokes. Not only can this technique be helpful to people looking forward to control overeating, it also might be helpful to people with drug addictions. This technique may be the key to a happier, longer, and healthier lifetime.

Sources (Picture and Article are from the same page) :

http://news.nationalgeographic.com/news/2010/12/101209-chocolate-obesity-science-mind-diet-weight-loss-eat-food/