My Biology 111 Wiki Blog


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Homework Post #1:

Anton van Leeuwenhoek (1632-1723)


external image H412408-Anton_van_Leeuwenhoek,_caricature-SPL.jpg?id=724120408
(sciencephoto.com)

Leeuwenhoek is not your typical scientist, for this era or his own. He had minimal education, next to no money, and no cultural awareness. He also had a broader mindset than most men in the 1600s, having not had his curiosity and passion lectured out of him during a painful education.
Leeuwenhoek is best known as “the inventor of the microscope,” even though he obviously was not. Both Hooke and Swammerdam had built compound microscopes as early as 1595, before Leeuwenhoek was even born. However, Leeuwenhoek was a natural. And that combined with his passion and curiosity on the subject after he had seen Hooke’s Micrographia was what made him so well known.
Although his microscope was not technically the first, I believe that Leeuwenhoek should have some credit. His microscope worked ten times better than those of the other two scientists before him and without Leeuwenhoek’s carefully documented observations we would not be where we are today.

Source:

Ford, B. J. 1991. The Leeuwenhoek Legacy. Biopress, Bristol, and Farrand Press, London. http://www.ucmp.berkeley.edu/history/leeuwenhoek.html



Homework Post #2:

Apoptosis


external image Apoptosis.gif


(microbiologybytes.com)
Apoptosis is also known as programmed cell death and cell suicide. These cells die in response to a variety of stimuli when they play the main role in their own collapse. The sequence of events that make up apoptosis has the purpose to elliminate cells in a controlled way that will not release detrimental substances into the surrounding area. Old, unhealthy and unnecessary cells are destroyed though this process. Apoptosis is essential to develop and maintain health.
Too much and too little apoptosis are main causes for a large number of diseases. When the programmed death of a cell does not happen as it should dangerous cells are left hanging around that can cause diseases such as cancer and leukemia. Occasionally apoptosis will go on overdrive and kill much more than necessary, damaging tissue and potentially causing stroking and neurologic disorders like Alzeimer's and Parkinson's. Apoptosis is sometimes induced because it is the most efficient and safest way for a cell to be detroyed.

Sources:

Dash, P. (2009, February). Apoptosis. Retrieved from http://www.sgul.as.uk
Definition of apoptosis. (2003, August 1). Retrieved from http://www.medterms.com



Post #1:

Fibromyalgia
external image tenderpoints.gif
(andersonpt.com)

Fibromyalgia is caracterized by widespread chronic pain, hightened response to pressure, and the 18 tender points depicted in the picture above. Other symptons are fatigue, sleep disturbance and stiff joints. Some patients also experience difficulty with swallowing, bladder and bowel problems, numbness and confusion. Not all victims of fibromyalgia experience all these symptons. There is no definite cause for fibromyalgia, but there are many theories and partial causes, such as genetics and stress. Fibromyalgia often occurs together with depression, posttraumatic stress, and/or anxiety. It is found in 2% of the population, and affects more females than males, with a 9:1 ratio, and is most commonly diagnosed in people between the ages of 20 and 50.
Fibromyalgia has no known cure, though there are vairous treatments. Lyrica, Cymbalta, and Milnacipran are all approved pharmaceutical medicines for fibromyalgia, though not all fibromyalgia victims report benefits from these medicines. Muscle relaxants are also used to help patients deal with their pain and tender spots. A healthy exercise regime improves fitness as well as sleep and may reduce pain and fatigue in some people with fibromyalgia. And exercise combined with some sort of medication has been seen as even more beneficial than either by themselves.

Sources:

Fibromyalgia myths. (2010, October). Retrieved from http://www.fibromyalgiatips.net/
Fibromyalgia. (2011, February). Retrieved from http://en.wikipedia.org/wiki/Fibromyalgia



Post #2

The Doppler Effect

Sheldon's Explaination and Demonstration

The Doppler Effect can be described as when the perception of light or sound is changed when the point of reference changes. It is most frequently noticed by the average person when we hear the sound of a car or motorcycle speeding down a street; it starts at a high pitch, then lowers. This can be explained by the sound waves emitted from the car. As the vehicle moves closer to you the waves in front of the vehicle are squished close together, they are moving at a higher frequency and make a higher sound. When the car passes you the waves behind it, which are spread out to emit a deeper sound, are the waves that will reach your ears. This phenomenon works the same way for light. However, since light travels much faster than sound, or anything else on earth, we can't see any examples of it in our lives.

Sources:

Youtube Video




Post #3

Camels


external image 250px-07._Camel_Profile%2C_near_Silverton%2C_NSW%2C_07.07.2007.jpg
(fohn.net)
Camels are by far the most disgusting animals I’ve ever seen. I had the opportunity to ride them with my family in Tunisia, Africa a few years ago. There are two species of camels. The dromedary camel, shown above has one hump and can be found in West Asia which the Bactrian camel, with two humps, is native to Central and East Asia. The camels we rode drooled a ridiculous amount. Male camels have a pink sac in their throat that hangs out of their mouths when they inflate. This is used in their mating rituals.
Camels are used for milk, for their meat and for their hair. Their hair is a useful source for woven goods. Their milk and meat can be found in places like Ethiopia, Australia, and Pakistan.

See a video of the mating 'sac' here: http://www.youtube.com/watch?v=lKGjDZ184gE

Sources:

Camel. (2011, April). http://en.wikipedia.org/wiki/Camel
Dromedrary. (2011, April) (http://en.wikipedia.org/wiki/Dromedary


Post #4

Allergies
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(specialcomment.wordpress.com)
An allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when in contact to an allergen, everyone is affected differently by allergens, some being not affected at all. Some allergens are a common source of allergic reactions, like peanuts and pollen seen above, and others are seen less, like fungi. There are also a wide variety of symptoms, some barely noticeable and others quite deadly. Some have reactions so severe, called anaphylaxis, that they need to have an Epi-Pen on their person at all times. An Epi-Pen, or Twinject, administers epinephrine that slows the allergic reaction, giving more time for emergency procedures to be put into action. Allergies can now be detected before a deadly situation through various tests. Tiny quantities of allergens are inserted into the skin and your body’s response is noted. They can also be detected by analyzing the level of allergen-specific IgE in one’s blood. Having no known allergies myself, I’ve never experienced any of these feelings or symptoms but as a lifeguard I know how to administer an Epi-Pen when needed!

Source:
Allergen. (2011, May). http://en.wikipedia.org/wiki/Allergen

Post #5

Eyes
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(msc2.ca)
I find eyes extremely interesting and I have definitely pondered a career in the area, and still have not out ruled it. I assume this has come from how much I’ve seen optometrists in my life. I had my first pair of glasses in grade five and only this year have my eyes begun to steady. Last time I visited the optometrist she showed me a picture of my eyeball and explained that the retina is simply where the photoreceptors are most dense. The reason why we don’t have good peripheral vision is because the photoreceptors become more and more scarce. Photoreceptors are a type of neuron that convert light into signals that enable us to see; called photo transduction. There are two types of photoreceptors, rods and cones. Rods are much more sensitive than cones and are triggered by only a small number of photons. Only this type of photoreceptor cell is active in the dark which is why no color can be seen.

Sources:
Photoreceptors. (2011, May) http://en.wikipedia.org/wiki/Photoreceptor_cell
Dr. Bronwyn Mulherin

Post #6

Legally Blind
File:Cataract in human eye.png
File:Cataract in human eye.png

(wikipedia)
Being legally blind is classified by the American Medical Association by a range of vision that is less than 20 degrees, where the norm is 180 degrees, or less than 20/200 vision in the better eye. These classifications include corrective lenses; there is only so much an optometrist can do for you. Someone legally blind with 20/200 vision would be able to see an object 20 feet away with the same clarity that a normally sighted person could from 200 feet away. The leading cause for blindness is cataracts. A cataract is a clouding in the area that focuses light onto the retina, in early stages it causes near-sightedness. It can be treated at this stage through surgery to prevent total blindness. In today’s society the blind can lead a fairly normal life. They can read, use computers, and walk about public spaces on their own. More and more technologies are being invented everyday to make their lives even more enjoyable.

Sources:
Blindness. (2011, May) http://en.wikipedia.org/wiki/Blindness
Blindness. (2011) http://kidshealth.org/kid/health_problems/sight/visual_impaired.html

Post # 7

Laser Eye Surgery

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(lovethatred.wordpress.com)
Laser eye surgery is becoming increasingly popular for those with vision problems. There are various kinds of laser eye surgery and different requirements for each. The most widely used is LASIK, laser-assisted in situ keratomileusis, which treats myopia (nearsightedness), hyperopia (farsightedness) and astigmatism (blurred vision). The term keratomileusis simply describes the medical procedure of using a surgical device- a laser in the case of LASIK- to reshape the cornea under a flap formed by lifting the surface of the eye.
Most doctors won’t consider LASIK until a patient is in their early twenties, and their eyes should be stable for at least a year before surgery. Also, pregnant and breastfeeding women need to wait until their hormone levels return to normal and eyes steady before the surgery. People with contacts must stop wearing them two to four weeks before the surgery depending on the type of contacts lenses because contacts change the shape of the cornea and will need time go to back to normal. Eyes must be healthy and free of conditions such as dry eyes and thin or steep corneas. The presence of autoimmune disease in the patient is also a health risk; there can be unexpected responses to the surgery.

Sources:
About Laser Eye Surgery. (2011). http://www.aboutlasereyesurgery.com/laser-eye-surgery.html
LASIK. (2011, May). http://en.wikipedia.org/wiki/LASIK



Post #8

Irukandji Jellyfish

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(wikipedia)
These small box jellyfish are found in the waters of Australia, the English Isles, near Japan, and along the Florida coast of the US. Their four tentacles can reach a length of one metre while their bells are extremely small, between five and ten millimetres in length. What makes them particularly unique is the presence of nematocysts on its clear bell as well as along its tentacles. They are also among the only known cause of the Irukandji syndrome, which it was named after. The syndrome is not fatal if medical attention has been obtained within 20 minutes of the sting, otherwise cardiac arrest is likely. Symptoms include severe headaches, nausea and vomiting, abdominal and chest pains, hypertension, accelerated heart rate, and the accumulation of fluid in the lungs. An odd symptom that victims have reported is a feeling of “impending doom,” patients are so certain they are going to die that they go as far as to beg their doctors to kill them to get it over with. They are 100 times more venomous than the cobra and 1000 time more so than the tarantula.

Sources:
Irukandji Jellyfish. (2011, May). http://en.wikipedia.org/wiki/Irukandji_jellyfish
Irukandji Syndrome. (2011, May). http://en.wikipedia.org/wiki/Irukandji_syndrome

Post #9

Mike the Headless Chicken

File:MikeTheHeadlessChicken.jpg
File:MikeTheHeadlessChicken.jpg

(wikipedia)

A chicken just like any other was born in 1945 on a farm inColoradoand was named Mike. One night five and a half months later, the farmer Lloyd Olsen chose Mike to be his dinner. However, when Olsen missed the jugular vein amazing Mike survived the ordeal. His head was mostly gone, leaving only one ear most of the brain stem intact. Mike was fed watered down milk and some small corn grains and after getting used to his new centre of gravity, functioned quite normally. He still attempted to crow but could only manage a gargling noise. Olsen and Mike went on the road where the young chicken was soon dubbed Mike the Headless Chicken, and sometimes Miracle Mike. One could see Mike for a cost of 25 cents, or in magazines and papers. At a motel inPhoenixin March 1947 Mike began to choke. The Olsens had accidentally left their feeding and cleaning tools at the side show that day and could only sit by and watch as their beloved friend and pet passed away. Mike was two years old when he left this world, 18 months of which were spent without the majority of his head. This is the longest reported case of a chicken living without its entire head.

Sources:
Mike the Headless Chicken. (2011, May). http://en.wikipedia.org/wiki/Mike_the_Headless_Chicken
Reference.com. How Long does a Chicken Live With Its Head Cut Off. (2011). http://www.reference.com/motif/Science/how-long-does-a-chicken-run-with-its-head-cut-off


Post #10

Rigor Mortis

external image _45651175_corpse.jpg
(news.bbc.co.uk)
The Latin words rigor mortis mean ‘stiffness of death.’ It is one the signs of death and is caused by a chemical change in the muscles. When this chemical change occurs the limbs become stiff and difficult to move. This chemical process usually starts three hours after death in a human, peeks in stiffness around 12 hours before the body begins to relax again for about 72 hours. Sources of heat can occasionally speed up the process of rigor mortis. Because the body has no source of oxygen once it’s dead the ATP stops being produced. Because the lack of ATP means that the calcium ions can not be pumped through the sarcoplasmic reticulum into the terminal cisternae, the calcium ions now diffuse to a lower concentrated area in the sarcomere and bind with troponin. This bind allows proteins myosin and actin to bind, creating a contraction. In this contraction however, unlike a normal muscle contraction, the corpse is unable to release the coupling between the proteins. The body will stay in a state of muscular contraction until the decomposition process begins, slowly eating the myosin heads of and relaxing the muscles. This information is used in forensic pathology when determining the time of death.

Sources:
Rigor Mortis. (2011, May). http://en.wikipedia.org/wiki/Rigor_mortis