Thursday, July 26, 2007

UNIT 4: SELF EVALUATION

Self and Unit Evaluation
My performance
1. What were the 3 aspects of the assignments I've submitted that I am most proud of? Basically everything, since it is a lot of work and information. The final lab was quite interesting and fun, so I guess I could say that I am proud of that assignment.
2. What 2 aspects of my submitted assignments do I believe could have used some improvements? Well, I put a lot of time into everything, so I would have to say they are all pretty much complete.
3. What do I believe my overall grade should be for this unit? since this is the final unit, and I am going by the same amount of work and time as the other 3: A.
Regarding the unit.
1. At what moment during this unit did you feel most engaged with the course? I usually pick the labs because they are more hands on, and take a lot of researching to complete.
2. At what moment did you feel most distanced from the course? I felt pretty good about this unit, probably because it is the last one so I knew what I needed to get done.
3. What action did the teacher take during this unit that find most affirming and helpful? I know I've said this before, but the emails you send are always beneficial.
4. What action was most puzzling/confusing? None, this was a pretty straight forward unit.
5. What about this unit surprised you the most? Before starting the final lab I thought, Man this is going to be hard! But it turned out to be fun and easy. When I brought my camera outside, there were species everywhere!!!!

Wednesday, July 25, 2007

UNIT 4: ETHICAL ESSAY

Who is in Control- Unit 4 Ethical Essay

Would you ever consider stopping at 2 children, just so you don't over populate the world? I know that China has a restriction on the births they are allowed, but is it necessary to monitor fertility rates? If you look at the graph to the right, you will notice that the fertility rates have decreased since 1950s, but in reality our population is continuing to increase(shown in the graph below). Of course resources may be a problem in the near future and by reading the articles I have written information regarding the big question, is population the problem?

While reading the articles I became a little annoyed by the fact the article repeatedly stated, a couple should consider having one child. "Consider having none or one, and be sure to stop after two" (vhmet article). This is something I disagree with totally. I come from a family of 8 and I don't not see any harm of us being here. For my own personal belief, I don't feel we should try and avoid having children. But for those that only want a couple children, that is fine. I don't think any different of them, it is their choice. And I hope that it will always be our choice. I'm not trying to start a debate, but God will continue to allow as many individuals on this Earth as He sees fit. Therefore the answer to the question; is population the problem, probably not. As mentioned above, even though there has been a decrease in fertility rates since the 50s, the population continues to grow. This could be due to the fact there is a lot of new technology and medications that are keeping individuals alive longer. We may be sustaining the lives of many individuals, but that is not in our hands. For those that believe it is important to have one child or as the same article mentions," some see parents as enemies of the planet," all I can say is I'm sorry they feel that way (vhemt article). By looking into the future always brings a million unknown questions.

The article also talks about the resources that are limited with the growing population. With overpopulated areas, such as Africa, this is a problem and as far as I know it has been for quite some time. Unfortunately in this area, may individuals are dying due to malnutrition and diseases. Is there a way to help prevent this from happening? I'm not sure. Hopefully these individuals will learn to protect and care for themselves, if they were given the information they need. The resources we have available to us now, hopefully, will continue to grow in the years to come. Who is to know what will happen. Obviously scientists have already concluded as the years go by our resources will be in high demand. I'm not sure this is completely related to the increase in population or is it not meant to last forever? After reading some of these articles I do realize that the overpopulation in the future will cause problems with how to supply and support everyone, but what could possibly be done?

In conclusion I would have to again note that I feel each of us should always have the choice of how many children we want. I hope it never comes down to the awful statement I read, "Consider having none or one, and be sure to stop after two." I know there a lot of unanswered questions, but to me it is hard to pinpoint what action should be taken. With the technology and research in today's society, I don't feel that our economy will ever slow down. Maybe this could be part of the problem when we become low on our everyday resources we count on?. There are many poor and starving countries that continue supplying us with resources we need to survive. Hopefully in the future we will continue to have the same resources available to keep us strong. Regardless of the change in fertility rates, I see our population rising due to the increase in technology available.

works cited
http://www.vhemt.org

UNIT 4 LAB- Demographics Lab

UNIT 4 LAB- Demographics



Graph above is the World and France- Low fertility rate




Graph above is the World and Africa- High fertility rate.



1. What was your high fertility rate country and what was its fertility rate? I used Africa and the rate was 5.90. click on the bottom graph to visualize.

2. What was your low fertility rate country and what was its fertility rate? I used France and the rate was 1.80. Click on the top graph to visualize.

3. The initial demographic "shpae" of your high fertility rate country should have been a pyramid, with high population in young age groups. Explain why high fertility rate results in a high percentage of young people in the population. How does this affect future population growth? Basically since the high fertility rate is in low developed countries, younger people do not have the income/knowledge for the use of contraception, or they are not familiar with Family planning. Which in fact has recently helped lower the fertility rate. The increase in fertility will obviously keep adding to our population growth.

4. Your low fertility rate country might have had a more oval-shaped curve with high population in middle age groups. This is especially exaggerated if the fertility rate is below 2.00. Explain why low fertility rate leads to lots of middle-aged people. While briefly reading articles about the different age groups I found an interesting point. More women are delaying having children till their middle-aged years, due to the fact that females are more involved in the work force and are continuing with education. Another reason may be because of the increased values; such as land,health care, education, and general needs. Also it is noted that more women in this class use contraceptives and are involved in family classes.

5. Write ten adjectives or descriptive phrases for what you might expect life, people'es attitudes, conditions on the streets, will be like for the following: low fertility rate

Middle-aged/older people: Most are content with life, for others nothing goes their way, well experienced, wealthy, streets are clean, know-it-all attitude, need assistance NOW, offer good advice, some kind while others rude, in this town RETIREMENT.

Children: Happy, living a care-free world, busy bodies, imaginiations, well provided for, well educated, take unkown risks, tend not to follow parents rules, careless, noisy.

Tuesday, July 24, 2007

UNIT 4- FINAL LAB

FINAL LAB: Biodiversity

The purpose of this lab was to name 20 species that we come in contact with on a daily basis. At first I thought this is going to be hard, but, once I took my camera outside and started on a walk, species were everywhere! This was actually an interesting lab, now realizing that we come in contact with numerous species throughout the day, without even realizing it. Below I have 15 species pictures, scientific name, common name, the ecological relationship, and wether I feel it is a Domesticated species, and how humans have been co-evolving with it. Hopefully you will enjoy this lab presentation.

1. Scientific Name: Carabidae, Ground beetle, Mutualistic, No: These insects are not harmful to us, but they do somewhat benefit by eating other little insects.

2. Scientific Name: Equus caballus, Horse, Animalia, Mutualistic, Yes: Pets. As you can see in this picture, we have horses as pets and are used as pleasure activity. On Mackinac Island, MI- horses are used for transportation, automobiles are not used on the island. Therefore horses are a benefical to us for transportation and pets.

3. Scientific Name: Arctiidae, Tiger Moth Caterpillar, Mutalistic, No: Insect. I don't feel we benefit from this insect, other than it eats other insects.

4. Scientific Name: Cophosaurus teaxanus, Lizzard, Mutualistic, Yes: Pets. We can thank these speedy creatures for going after the little annoying insects before they come into our homes. Some individuals also benefit from lizzards as a pet.
5. Scientific Name: Ictalorus punctatus, Channel catfish, Commensal, No: Fish. I'm not sure if this is actually a catfish, but for the most part we benefit from fish since we eat them as food.

6. Scientific Name: Family Anatidae(Atix Sponasa), wood duck, Mutualistic/Commensal, Yes: Pet and Food. I would say both since we as humans may eat duck, and the ducks eat insects.
7. Scientific Name: Cupraea zebra, Cowrie Snail, Mutualistic/Commensal, No. I would again say both, since snails eat insects, and some individuals eat this species.

8. Scientific Name: Lepus califonicus, Jack Rabbit, Commensal, Yes, Pet. These little animals are speedy, but also can be annoying when they munch away on your flowers/fruit!
9. Scientific Name: Teleogryllus commodus, Field Cricket, Mutualistic, No: This insect tends not to harm us, but does help rid of other insects. Although, I love listening to crickets in the evening. When I lived in MI there was an abundance of them, although when they land on you they are hard to remove!!! IICCK.
10. Scientific Name: Aphonepelma chalcodes, Wasp, Mutualistic, No: Again, wasps eat other insects. In the same category, bees, supply us with delicious honey!

11. Scientific Name: Opodiphthera eucalypti, Moth, Mutualistic, No: I would have to continue to repeat myself and say that it eats other insects, and typically doesn't bother us.

12. Scientific Name: Anisoptera Carnivorous, Dragon fly, Mutualistic, No: These insects are actually speedy and again help rid of insects.

13. Scientific Name: Zenaida Macroura, Mourning Dove,Mutualistic, Yes: possible pet, and food. Since birds eat insects/worms for food, this is benefical to us.

14. Scientific Name: Chionactis Occipitalis Annulata, Shovel-Nosed Snake, Mutualistic/Predator, No: Reptile and its disgusting. I actually found this NASTY snake in our bedroom! Needless to say, through my freaking out, I grabbed my camera, and clicked pictures before we got rid of it!!!!!! Some snakes could be classified as preadators while other little snakes such as this feed on insects. This could be both.

15. Scientific Name: Chiroptera, Bat, Predator, No:Rodent. This is also a disgusting sight my husband and I came across on our steps!!! It was day light and the bat laid there, we actually though it was dead until we moved it around. (thats when I got my best pictures) The teeth of bats are absolutely disgusting!!!! This predator is actually beneficial in that it eats other rodents and insects, eventhough they are nasty creatures.
Other Species: Scientific Name, Comman Name, Ecological Relationship, and wether I think it is a domesticated species, and how we as humans are co-evolved with it.

16. Cimicidae, Bed Bug, Parasitic, No, This disgusting species feeds off of our bodies, there are numerous bed bugs on us, without us even knowing.
17. Coccinellidae, Lady bug, Mutualistic, No: The lady bug doesn't really benefit us, other than eating other insects, some can be annoying.
18. Culiciade, Mosquito, Parasitic, No:This species also feeds off of us, by biting and eating our blood! We definately do not benefit, but the mosquito does.
19. Danaus Plexippus, Monarch Butterfly, Symbiotic, No: This species minds its own business, although other speceies feed on it, while the butterfly feeds on things such as flowers, not harming anything.
20. Zea, Field corn, Commensal, no: Since corn on the cob is in season, I picked delicious corn. This species definately benefits us, while the corn in unharmed.
21. Lactoca Sativa, Garden Lettuce, commensal, no I would just repeat from above.
22. Prunus Persica, Peaches, Commensal:no again, we benefit from the peach trees, since they supply us with scrumptious peaches. While other species may nest and feed off of the tree too.
23. Bos Taurus, Beef, Commensal(since it comes from cows) Yes: cows supply us with beef and milk, therefore very benefical to us.
24. Myosotis Discolor, For-get-me-not flower, mutualistic, No: Insects feed off of the flower, unharming the flower: benefical to both.
25. Ferocactus wislizeni, Barrel cactus, not sure, cactus's are mainly a part of our enviornment, although some use as house plants.
26. Homo sapien, Human: It seems as though you could classify humans as symbiotic, since we have relationships between many different species. Although the majority of food we eat comes from a living species, do we classify us as commensal too?
27. Canis Familiaris, Dog, Mutualistic, Yes: Dogs are important and very benefical to many individuals. They are protectors and pets.
28. Carislatrans,Coyote, Predator, No: This species feeds on other organisms for prey, and basically have no benefit to us.
29. Bubo virginianus, Great horned owl, Predator, No: I think this is the same, although they do help rid of rodents/insects. We actually saw an owl the other night, but could not tell which kind it was. I'm not sure which is popular in this area, so I picked the great horned owl.
30. Family formicidae, Ants, Mutualistic, No: Have you every watched an army of ants?? They are amazing little insects- they constantly move in a line carrying pieces of food, bigger than itself, to its home. Ants are also benefical to plants.

In conclusion, I named 30 species, 15 have pictures, and also noted the scientific name, comman name, ecological relationship, wether I feel it is a domesticaed species, and how the species is benefical or not benefical in our eco system. Again, I found this lab to be interesting. While looking up the scientific name, I also breezed through the life of the species which was also interesting. Hopefully this lab was interesting and worth the time I spent clicking pictures of the many species we come in contact on a daily basis. Many of the species ended up being Mutualisitic and benefical to our eco system.

Friday, July 20, 2007

UNIT 4: Human Landscapes & Ecology, compendium 2


TOPICS


1. Deep time Evolution History
2. Natural Selection

3. Physical Landscape

4. Biological Landscape

In this review I will try and explain the different aspects of the environment we live in. My first review is that of evolution history, and how scientists became interested in study the lives of fossils and how our planet Earth got here in the first place. Next I will talk about Darwin's studies on specific species, and why they have different physical appearances. The next two topics will be related to the environment, and how we get our resources we need. I hope this review gives a little understanding of the wonderful world we live in!

DEEP TIME EVOLUTION HISTORY. The first sentence of this chapter states: "Our study of evolution begins with the origin of life" (Mader 468). We all of unknown questions of how things are how they are, and for me I am not one that likes to go into detail to find out why something is. So this section is going to be difficult. Mainly because I believe that God has made all of these things in the beginning of time. The first question of this section is how did the first cell get here? A scientist, Stanley Miller, experimented on different gases similar to the Earth's atmoshpere. His end result of organic molecules sparked interest in other scientist, formulating a plan that RNA needed to be present and protein was a factor. An interesting comment was made on a website: "evolutionary changes are documented in layers and layers of rock deposited over 4.6 billion years" (pbs article). Reading through different articles, geological time is referred to as deep time. The picture to the right gives an example of how we us layers of rock and fossils to research. Fossils are, "the best evidence of evolution because they are the actual remains of species that lived on Earth" (Mader 470). The picture to the right is a fossil of an early bird known as Archaeopteryx. The picture below shows it is an arthropod- Fossil Trilobite.
A scientist known as Charles Darwin traveled around the world finding evidence of different form of life, mainly in fossils. He also later explained the anatomical evidence, the vertebrae forelimbs had all the same bone structures. The picture to the right is referring to the modern skull(right) and a Neandertal skull(left). "All people today are classified as Homo sapiens" (antrhopal article). Humans today have a more delicate skeleton structures.

NATURAL SELECTION. "A species becomes suited to its environment" (Mader 474). This is part of Darwin's collection of evidence as he traveled. The picture to the right is an example of Darwin's research on different style beaks on Finches. "The beak of each species is suited to its preferred food, suggesting that beak shapes evolved from natural selection" (wikipedia article). The book labels 3 different elements important in natural selection: Variation(physical appearance), Competition for limited resources, and Adaptation. This is was an interesting section, that I was not aware of. Each species tends to adapt to their own comfortable life style, some end up changing their physical appearance as generations are passed.

PHYSICAL LANDSCAPE. "The biosphere is where organisms are found on planet Earth, from the atmosphere above to the depths of the oceans below and everything in between" (Mader 493). The organisms function not only amongst themselves but also with the chemical and physical aspects within their environment. This interaction is known as the ecosystem. All of the little creatures scurrying around and flying above us are part of the food web, obviously allows there to be a constant cycle. Energy flow is important for each organism, plants get energy from the sun and people get energy from food. The Water Cycle is involved in evaporation from the ocean, leaving behind the ion, salt. This forms our wonderful rainstorms(precipitation) in both water and land. This percipitation then evaporates from both land and water, and eventually returns back to the flowing depths of the water. As a society, we definitely disturb this cycle. The Carbon cycle us referred to as: "producers take in carbon dioxide from the atmosphere and convert it to organic molecules that feed all organisms" (Mader 500). Next is the Greenhouse effect, which is basically known as the Earth getting warmer and warmer. Due to the increase in one of the greenhouse gases, Carbon dioxide, gets trapped inside and doesn't go pass back into space. Again, this causes the Earth to get warmer by absorbing more sunlight. These cycles will continue circulating our ecosystem and hopefully we, as a society, will continue protecting the environment we live in.

BIOLOGICAL LAND. The main resources we as individuals use daily are: land, water, food, energy, and minerals. As our population continues to grow, we need to monitor and watch where we are developing, in order to maintain a healthy environment. The land we live on ranges from beaches, deserts, mountains, rain forest, tropical, and numerous others. In some areas water is very minimal, therefore people use dams, reservoirs, and groundwater tunnels to help keep one of their resources readily available. There seems to be an over abundance of food, but it depends on what type we are talking about. Most of our food comes from: our gracious farmers who continuously maintain their crops/livestock, and fishermen out at sea. We also need to take into account our worst environmental nightmare: pollution. The book names several concerns regarding pollution: "Acid deposition, Global warming, Ozone depletion and Synthetic organic chemicals" (Mader 525). Another bad note the book relates to is Biodiversity crisis; our species in the near future are slowly dwindling away. To end this on a good note, at least for myself, we need to focus on today and not worry what is ahead of us in the future. I understand there are reasons to be concerned, but some things are taken to extreme.

In conclusion, I discussed many different topics relating to our environment. From the beginning of time when we, as humans, supposedly dated back to apes/monkeys. I did find it interesting while researching fossils, and what scientists discovered by looking at them. For instance the pictures above I found of different birds. How amazing that they are able to identify the leg and wing structures of a species, dated back many centuries ago! For the other sections, I basically feel we need to continue protecting our environment. We are blessed to be here, so we may as well care for the land we live on.

Works Cited:
Mader, Sylvia S. Human Biology. Boston: McGrawHill Companies, Inc. 2006.
quotes
http://anthro.podomar.edu/
quote, picture of skull-modern and Neandertal skull
http://en.wikipedia.org/wiki/natural_skeleton water cycle, food web
pictures related to above key words
http://www.pbs.org/wbgn/evolution
http://www.ucmp.berkley.edu/
pictures of fossils

Wednesday, July 18, 2007

UNIT 4: Reproduction Lab

The purpose of this lab was to identify 10 things that are significant throughout fetal development. I'm sure most of us agree that everything that occurs in fetal development is important. I am 20 weeks, and I have been following along week by week, and it's is astonishing of what is actually going on inside of me. There is a little life, faithfully growing day by day. Pregnancy is fascinating, even though there are difficult scenarios that occur while carrying an unborn babe. Below I will briefly describe the 9 months of fetal development and within each month there is more than 10 significant events. Hopefully this is a good overview of what occurs during fetal development.

To begin, the first month is most important to maintain a healthy diet and protect the little baby about to grow. During the first 2 weeks there are a lot of changes occurring. Fertilization occurs within the first week and the following week the embryo implants itself to the wall of the uterus. This implantation stage is quite important because this is the home of the baby for 10 months. The 'tear drop' picture to the right is an example of an ectopic pregnancy, the embryo attaches to something other than the uterus. The other picture is during the first month: weeks 4-7. A major organ that develops and starts working in the heart, it begins beating at about 6 weeks. Also during weeks 4-5 tissue develops, and blood begins flowing through the vessels. I feel there are all important part because a heartbeat is one of the first signs that the baby is beginning to grow, and blood flood flowing, shows the systems are getting prepared for the following months

During month 2(8-12 weeks) most of the major organs appear, most are bud-like shaped. This is an important part for the mother to be cautious of what she is consuming: avoid drugs/alcohol, and limit the amount of stress. The first trimester is considered the crucial stage, due to the embryo's complex development of organs. Although at the end of the 8th week the embryo stage ends, and the fetal period begins. The picture to the right is that of a 2 month fetus/embryo, note its beginning to take the shape of a human. The amniotic fluid supports/surrounds the embryo/fetus from week 3 to 10. Without this structured fluid and the germ layers, the baby would not be protected during development.

During month 3(13-16 weeks) the organs are still immature. During this point, the brain has the basic brain structure and spinal cord. As you can see in the picture to the right, the fetus is growing and more human like than the previous month. Muscle tissues and bones continue growing and supporting the fetus. During the next months, the uterus increases in size.
During months 4(17-20) and 5(21-24) During this developmentt phase, the mother most likely should feel a fluttering sensation! This is the sweetest/amazing feeling. It's a mile stone, knowing that your baby is growing and able to move around! The picture is 20 weeks, how precious(this is what my baby looks like)! The white 'lanugo' covers the entire body. Also, the brain is now fully developed. The fetus can suck, swallow, and make different noises. The Ultrasound picture is of 20 weeks, baby sucking his thumb! Ultrasounds are typically done between 18-22 weeks to help monitor the growth of the fetus, and make sure the fetal development is progressing.

During month 6(24-29 weeks) "The developing fetus is totally dependent on maternal organ systems for nourishment, respiration, and waste removal" (Martini 1089). Again it is important that the mother continue to maintain the recommended nutrients and vitamins to help keep the baby growing and functioning safely. The picture to the right is a fetus at 24 weeks. The waxy/white covering his eyebrows and body is a protective layer called vernix. This is important to protect the baby during the last months of development. Another important event occurring in this month is the alveoli forming on the lungs, typically during week 24. All of these are important in providing the fetus with a healthy development.

During the 7th month(30-35) and 8th(43-37) and 9th month(38-40) The fetus's breathing is rythmic, but not yet mature, usually they are by 38-40 weeks. By the 8th month the fetus is preparing to enter the world. The brain and nervous system are well on there way to being fully matured. The fetus is considered full term at 38-40 weeks, and ready to show off his amazing development inside his home for nearly 10 months!!!! The picture to the right is a fetus smiling at 40 weeks, ready to live outside his mother. After birth, the baby still continues to develop, especially the lungs!

Following each month or week of pregnancy definitely proves that every part of the development is important. It said to explain why I think each is important and it's obvious, because the events I mentioned are necessary in order for the fetus to grow and develop into a healthy baby. The picture to the right is a college of ultrasounds throughout the development of a fetus. Unfortunately there are babies born with birth defects and disorders, but for the most part it is out of our control. I just pray that I will be blessed with a healthy baby, come December!! Hopefully this review on the fetal development helped show what I think is significant, EVERYTHING!
works cited:

Martini, Frederic H. Fundamentals of Anatomy and Physiology. San Francisco: Pearson Education Inc., 2006.


pictures- month 1 and 2


pictures- last 2 pictures


pictures-'tear drop', ultrasound, other fetus pictures

Tuesday, July 17, 2007

UNIT 4: REPRODUCTION Compendium Review-1

TOPICS
1. Human Life Cycle: Mitosis and Meiosis
2. Male/Female Reproductive Systems
3. Fetal Development and Birth
4. HIV/AIDS
Let me begin by saying that reproduction is the process of a sperm and a fertilized egg joining together, and forming a miraculous new little individual. In this section I will be discussing the above topics in a more detailed fashion. To begin, I would like to discuss the 2 different cell divisions in the human cycle: Mitosis and Meiosis. Next I will review the Male and Female reproductive systems that aid in the development of a new organism which leads into the next topic: Fetal development and Birth. Lastly I will go over a few of the common STD's. The beginning life of a fetus is an absolute miracle, that I myself am blessed with right now.

HUMAN LIFE CYCLE: MITOSIS AND MEISOSIS. We learned in prior chapters of the 2 different phases associated with the human life cycle: Mitosis and Meiosis. Glance at a scanner and then at the finished picture, this "duplication division" is known as Mitosis (Mader 320). This process occurs throughout the cell development. Recall that this process goes through 4 different phases: Prophase, Anaphase, Metaphase, and Telephase. The second process is Meiosis: " A specialized process of cell division that produces gametes(eggs and sperms)" (ref article). It is also known for reducing its diploid cells to haploid cells. In number sense; a sperm and egg both carry 23 chromosomes, therefore when fertilized the new cell has 46 chromosomes. "The first cell of a new human being is called the zygote" (Mader 320). During this step, the offspring gets a copy of each parents chromosomes. And the sex of the baby and hair color is determined at this point. The picture to the right is the process of the haploid cells(egg and sperm) joining together to form the zygote. To lead into the next topic I would like to mention where the production of sperm takes place in the male and females. Most of us have studied this before, but in review the males produce in the testes and the females in the ovaries. Now that we have a general idea of the egg being fertilized, I would like to discuss the male and female reproductive systems.

MALE REPRODUCITVE SYSTEM: Testes, Epididymis, Vas deferens, seminal vesicles, Prostate gland, Urethra, Bulbourethral glands, and Penis. To begin this system, once the sperm has begun production in the testes, the epididymis is the actual site where it matures. The traveling sperm enters a long narrow tube, vas deferens, which is also a storage organ. This leads to the ejaculatory ducts, which enters into the urethra. The seminal vesicles "contribute nutrients and fluid" (Mader 321). The other glands that are helpful in providing fluid for the sperm are the prostate and bulbourethral glands. The testis have seminiferous tubules, which are packed with little cells going through spermatogenesis "the production of sperm" (Mader 323). Hormones play a big role in the sexual drive, gonoadotropin-releasing hormone(GnRH), release 2 well known hormones: follicle-stimulating hormone(FSH) and lutenizing hormone(LH). "FSH promotes the production of sperm, LH controls the production of testosterone" (Mader 324). This occurs in the males.

FEMALE REPRODUCTIVE SYSTEM: Ovaries, Oviducts, Uterus, Cervix, and Vagina. Again, the ovaries are the site of egg production. The 2 hormones in the female system are estrogen and progesterone. To start the cycle, the oviducts most commonly known as the fallopian tubes, is the spot of fertilization. During ovulation, the little egg is guided to the fallopian tubes from 2 different sweeping actions, fimbria and cilia. "A developing embryo normally arrives at the uterus after several days, and then implantation occurs" (Mader 324). The uterus is where the developing fetus lives. This organ is very muscular and durable, just think, the average 7 pound baby kicks around inside of this structure!!! The vagina has 2 different functions: penis enters during intercourse, and it is the pathway canal during delivery. The females also release the FSH and LH, as do males. These hormones are important during the ovarian cycle. Fertilization occurs when the sperm travels its course towards the fallopian tubes. This is the beginning stage of Pregnancy. The next topic will describe the fetal development process.
FETAL DEVELOPMENT: At this point, the developing baby is known as an embryo. The development is divided into 3 different stages: Pre-embyonic(which is mentioned above- takes place during fertilization), embyonic(week 2-2 months), and fetal development(3 months-9th month). There is so much information during each week of pregnancy, that it's hard to know where to start! During the embryonic development, the embryo implants itself to wall of the uterus, its home for 10 months! I remember looking at these pictures when I first found out I was pregnant thinking, WOW, these structures are forming into my little baby! The picture to the right shows the 1st week, not yet pregnant, but the conception stage. During the embryonic development, the hormone secreted is HCG, which helps distinguish pregnancy if a pregnancy test were taken. The book describes this tiny embryo as being the size of a"period at the end of this sentence" (Mader 357)!!!! Organ systems begin to develop later in this stage and by the 8th week the embryo looks more human-like. The picture to the right is an embryo at 8 weeks. As pregnancy progresses, the uterus grows as well. The fetal development is also an interesting part because the fetus's heartbeat can be heard with a doppler, starts its first awakening flutter sensation, the mothers belly is growing, and all of the systems are fully developed. As the months go on, the baby's body slowly forms into a proportional size. The picture below is a fetus at 23 weeks. There are obviously changes that occur in the mother during pregnancy. The book states the following changes: "Energy level fluctuates, uterus relaxes, and pulmonary valves increase" (Mader 368). Aside from those changes, the mother also experiences hormonal changes, body changes, and feelings of sickness. In the end these changes will be worth the miracle baby!


BIRTH. The first sign of labor, is the strength and timing of the contractions. "True labor is marked by uterine contractions that occur regularly every 15-20 minutes and last for 40 seconds or longer" (Mader 368). There are times that the mother may think she is having a contraction near the end of her pregnancy but is in fact known as, 'false labor.' The 3 stages of birth are: Stage 1 (dilation of cervix) Stage 2(child is born) and Stage 3(placenta expelled). There is much more emotional and physical details that could be added, but for this review I feel that the point is clear.


HIV/AIDS. "No war, natural disaster, or terrorist attack has ever killed more people than HIV/AIDS" (Mader 352)! That is absolutely sad, I wasn't aware of that fact. "World wide, an estimated 38.6 million people(36.3 million adults and 2.3 million children) are now living with HIV infection" (Mader 344). Scientists have been struggling to find a vaccine to prevent the spread of this horrific disease. There are many important factors that they need to study, such as: is the vaccine a short term protection and would it make the individual more vulnerable to the disease? HIV travels into the body and destroys the immune cells. Mainly the Helper T cells which are used to help destroy the body from infections. Many of the individuals living with this disease are those living in poor to low income countries. At the the top of the list is Africa and Asia, Latin America and Caribbean, North America, Europe and Central Asia, and final North Africa and the Middle East. As we are aware the transmission of HIV is through sexual contact, and sharing of needles with an infected person. There are drug therapies available, but it does not cure AIDS, it is used as treatment to help stop the spread into the cells of the body. Hopefully scientist will find a vaccine to help control this deadly disease. STDs caused by viruses are : HIV, genital warts, genital herpes, and Hepatitis. STDs caused by bacteria are: Chlamydia, Gonorrhea and Syphilis. Antibiotics are a way to cure the bacteria STDs. Again, hopefully the spread of these STDs will decrease as individuals avoid the chain of transmission.

In conclusion, I discussed the human cycle and how amazing it is to look at pictures of the process of the unborn baby. Meiosis is the process of game production, it reduces its diploid cells to haploid cells. Making a total of 46 chromosomes when the new cell is fertilized. I also reviewed both the male and female reproductive organs. Next I reviewed the process of fetal development, and how amazing each day the embryo/fetus grows! I actually go into more detail in the lab section, so I did not repeat myself in this review. Since I am pregnant, I feel its natural to be a little nervous that for some reason something may go wrong. Obviously there are babies born with certain deformities, and diseases, I just continue praying I will be blessed with a healthy baby. The last thing I discussed was STDs and HIV/AIDS. I will just repeat that hopefully individuals will think before the act, to help stop the spread of these horrific diseases!! I hope this review was worth while.

Works Cited:
Mader, Sylvia S. Human Biology. Boston:McGrawHill Companies, Inc. 2006.
quotes
http://www.americanpregnancy.org
first picture
http://www.med.upenn.edu/meded/public/berp/overview/BV-1.html
picture of embryo at 8 weeks
http://www.pregnancy-calendars.net
picture of fetus at 23 weeks
http://www.-ref.usc.edu
quote, picture of meiosis

Thursday, July 12, 2007

UNIT 3: LAB PROJECT MOVABLE LIMB

MUSCLE CONTRACTION- LAB


As you are bending down to pick up a penny off of the ground, a process occurs in your limbs and tissues in order for this movement to take place. This lab project will hopefully give you a better understanding of how a muscle moves; my example is of a knee joint. Skeletal muscle is one the the 3 muscle tissues in the body, which are needed in order for a contraction to occur. "Skeletal muscle tissue moves the body by pulling on bones of the skeleton" (Martini 284). Within the skeletal muscle tissue is a single muscle fiber. My lab project shows in detail the start of a contraction, which occurs when an electric impulses travels down the length of a muscle fiber. Before it even gets to the muscle fiber, a motor neuron is the carrier of the information that brings the impulses away from the CNS to the muscle fiber. The axon is a snakelike figure that extends off of the motor neuron, responsible for conducting nerve impulses. I will also be describing the process of action potential, which is a nerve impulse traveling down the axon. At this point by reviewing the pictures will hopefully give a better understanding of how a muscle begins a contraction. There are 6 functions of a skeletal muscle: Movement, maintain body position and posture, support soft tissues, protect particles that enter and exit, maintain body temperature, and store nutrients. These functions are all necessary in order to provide a healthy movable muscle.



Above is a picture of a movable limb: a femur bone, tibia bone and between is the synovial joint. The middle picture is the same limb, but showing the Sartorium muscle, which helps with flexion of the knee and hip and also with rotation of the hip. There are several classifications of synovial joints, which basically allows for different types of range of motion. The knee joint can be described as a hinge joint, which allows motion similar to opening and closing of a door. The picture to the far right is a picture off of a website, but in more detail of the same limb I used.


Above is a picture of a motor neuron(green foam) the white strings off of the neuron are dendrites, the skinny white string is an axon, the pink beads represent the mylein sheath which is covered by Schwann cells, and the twizzler is a muscle fiber. As mentioned above the motor neuron carries nerve impulses away from the CNS to a muscle fiber. Messages are received from other neurons at the dendrites(strings off of the motor neuron). These messages are then passed onto the axon(skinny white string), in a form known as an action potential. At the end of each axon are synaptic terminals( a synapse is also a part), which is involved in the communication method to other cells. This picture basically shows how the neurons are moving towards a muscle cell, sending messages down the axon in form known as action potential getting ready to start a contraction.



This picture shows where the action potential occurs. It moves along the axon, stimulated from the electrical impulses. At first I used a white string for my axon, but for vision reasons I switched to a twizzler.




The next process is that of nerve impulses. Basically it is information that is moving along the axon, in the form of action potential, the electrical impulses are known as nerve impulses. There are 2 types of potentials: Resting(axon has no impulse movement, -65mV) and Action("rapid change in polarity across an axonal membrane as the nerve impulse occurs") (Mader 250). The pictures above are both Action potential. The first one is when the Sodium gates open(green balls are sodium) and Sodium enters the axon. The Potassium gate (blue structure) remains closed at this time. During this process, depolarization occurs, which is caused from the axon becoming more positive with the entrance of sodium. "The potential changes from -65mV to +40mv" (Mader 250). The next picture shows reporization: Potassium ions move out of the axon making the inside negative again. During this phase, Sodium gates are closed and Potassium gates swing open.





This picture is inside of the muscle fiber, showing the T tubule(black strings) and the sarcoplasmic reticulum (pink thread). The plasma membrane of a muscle fiber is known as the sarcolemma. T tubules are networks inside of the muscle fiber that carry electrical impulses to the cell. One of the important parts of the sarcoplasmic reticulum is that it is a storage unit for Calcium ions. The spider web structure formed from the T tubules and sarcoplasmic reticulum hold together hundreds of myofibrils. Inside the myofibril are many sacromeres. These structures are bundled with proteins: Thin (actin) and thick(myosin); these protein molecules are responsible for the muscle fiber to contract.



This picture shows the 2 different filaments I just mentioned. Note the little flaps on the Myosin structure(twizzler) these are called myosin heads, later I will show the interaction of the head connecting to the Actin, these are known as cross-bridges. The actin is intertwined with 2 strands: tropomyosin(pink string) and troponin(large green beads).

The start of the contraction begins when the neurotransmitter acetylcholine(ACh) is released and binds to a messenger in the sarcolemma(plasma membrane of the muscle fiber). This impulse travels down the network of T tubules and ends intertwining sarcoplasmic retiuclum. Calcium ions are released which leads to a sacromere contraction. The picture to the far right shows the release of calcium ions(yellow balls) which attach to actin filaments- on the troponin protein thread(large green beads).



Once the Calcium ions are attached to the Troponin, this causes the tropomyosin(pink string) to shift away, making room for mysoin to bind to actin. The picture above shows this process. The head of the mysoin attached to the actin filament. At this point ATP supplies the needed energy for a contraction to occur. The cross-bridges as mentioned above are a part of this process. Contraction beings when this cycle of cross-bridges binding, pivoting, and detachment occurs repeatedly. "The muscle fiber contracts as the sarcomeres, within the myofibrils, shorten" (Mader 232). Its difficult to show how sliding filaments work, but the actin filament slides toward the center of the sacromere when the head of the myosin pivots to the base of the actin filament. "When muscle cells contract, they create tension and pull on the attached tendons" (Martini 321).

In conclusion, our bodies are made of many cells, tissues, and muscles that help keep us functioning every second. This lab was definitely a piece of work, but it gave me a strong understanding of how a muscle contraction occurs. The skeletal muscle contains many muscle fibers packed with myofibrils. The myofibrils consist of sacromeres which are composed of thick(myosin) and thin(actin) filaments. When a sacromere shortens in length and actins slide past myosin, a muscle contraction occurs. The picture to the right is a quick outline of what I described throughout this lab. It's amazing how all of these processes I described occur in order for a muscle to move. Hopefully my write-up was helpful in showing how a neuron moves through the body just to allow you to bend a pick up the penny off of the ground.


Works cited:
picture of knee-muscles
Mader, Sylvia S. Human Biology. Boston: McGrawHill companies, Inc. 2008.
quotes
Martini, Fredric H. Fundamentals of Anatomy and Physiology. San Francisco: Pearson Education, Inc. 2006.
quotes