Post-Pig Dissection

       The most interesting part about the pig dissection, was how closely the interior anatomy resembled the textbook. Every organ was positioned as it was in the drawings, only difference being the scale of these organs. I was shocked at how massive the liver was compared to the other organs. In comparison, the stomach and the other digestive organs were overshadowed by the liver, that also surprisingly resembled the shape seen in pictures. 

Another interesting observation I made on the fetal pig was how closely it resembled its adult counterpart. Prior to the dissection, I was under the assumption that the fetal pig would be more embryonic and primitive - barely resembling the post - birth piglets seen in everyday life. I conclusion, I found the pig dissection to be very enlightening and  surprising as it taught me not only to never make broad assumptions when it comes to science, but it also taught me to see our bodies through a different lens. Through the eyes of a mechanic, an architect, an engineer, and a visionary.

Engagement in Biology

        Engagement is a funny word. What may seem like active and dymamic involvement in class may seem as being passive and detached through the eyes of another. To me, the level of engagement is directly tied with confidence in one's ability and knowledge. If you are confident in your understanding of the course, you are sufficiently engaged. One may argue - on a superficial level of analysis - that the level of confidence is directy correlated to the numerical value displayed on a report card. I personally agree to this asertion to an extent, however I maintain the beleif that detachment and high marks can be mutually exclusive. To me, engagement can be seen in every question asked, every subtle nod, every weak smile, and in every thought explored. Throughout the year I firmly beleive that I have adequetly displayed such engagement and this level is wholeheartedly refelcted in my marks, and my confidence.

Heart Dissection

         Every now and then, we receive the remarkable opportunity of observing the marvels of biology not from a textbook, but in person. The heart is a remarkably adamant organ which takes its job to the extreme by providing an around-the-clock pump for the body's circulatory system. Here are just some of the observations made on this beloved organ:

1) Compare the structure of the atria and ventricles - how are they different?  Why is that?

 Perhaps the most distinguishing feature for the atria were their relatively diminutive size when compared to the more muscular and rigid ventricles. Almost sac-like in appearance, the atria were spongy in texture and were flexible and 'inflatable.'They seemed almost detached from the heart structure, and almost looked like flaps serving no apparent structure. The atria need to be flexible in order to expand when blood rushes through them. They must have sufficient capacity to store the blood, and then must then be able to deliver it to the ventricles. The ventricles are much more muscular (left one being more so) in order to squeeze blood at a high velocity. The left ventricle in specific must be powerful enough to squeeze blood to the entire body, whereas its rightward companion need only to deliver the blood to the lungs.

2) Did you notice a difference between the veins and arteries entering and leaving the heart?  How is their structure different?

 The arteries leaving the heart were very thick and more rigid than the veins entering it. The walls for the arteries were much more thicker, and the diameter was narrower in order to increase pressure and velocity - without the walls giving in. The roles however switch when it comes to the pulmonary system, as the veins and arteries are essentially switched.

3) Describe the valves that you found in the heart - what are their functions?

The tricuspid atrioventricular valve allowing blood from the right atriam to enter the right ventricle was similar to the bicuspid atrioventricular valve between the left atrium and the left ventricle. The valves were narrow and guided the blood to the ventricles. They had thin strings (Chordae Tendinae) attached to prevent inversion. Their purpose is to control the amount of blood entering the ventricles, without inverting and allowing blood back into the atrium. The semilunar valves prior to the pulmonary trunk and the aorta were cresecent-shaped and were fairly concealed and tucked away. They purpose is again to control the output of blood without and straying and flowing backwards.

4) What surprised you about dissecting the heart?  Why?

I was most surprised over how large the blood vessels are in actuality. Seeing them in a textbook gives them an elusive nature of being concealed, and far too small to be easily manipulated. However, I soon found my entire finger sliding through one of these vessels (the aorta), with dare I say surprising ease. For some reason I was under the illusion that such a vital vessel would be much more fragile, almost delicate in sense. To my surprise, the vessel was able to sustain the abuse delivered to it through many a prodding and poking. Amazing.

Why Eating Beets Can Lead To Some Startling Discoveries

              You're just finished your business after almost rupturing your bladder from the wait, and are just about to leave when you notice. Your urine is red! Now before screaming in horror and dialing the nearest hospital, think back on your day and reflect on what you ate. Chances are, you probably had a beet recently.

                
            Known as a phenomena called "Beeturia," excreting red-urine from your urethra can be a tell-tale sign that you may be low on iron. Experts suggest the science behind it relies on "pernicious anemia, which is a chronic condition caused by gastric atrophy which leads to deficient intrinsic factors to process B 12." However, the reasoning behind it isn't that simple. Some evidence points to a genetic problem resulting in being unable to metabolize betalaine - a red pigment. So if you are part of the 14% of people that get a shocker after eating beets, don't feel the need to drop your beet consumption as they are very healthy.

          Iron deficiency, known as anemia, can be compensated by eating a diet rich in dietary iron. Dark leafy vegetables, fish, and eggs are an excellent source of such iron and should be consumed regularly. Beets also carry this iron, along with a host of other 'goodies' such as magnesium, calcium, and folic acid. Beets can cleanse and protect the body through increased production of immune cells and healthy metabolic processes.

So eat up! Just make sure to flush!

http://voices.yahoo.com/sporadic-red-urine-may-beeturia-46741.html


         

Circulation Celebration of Learning

The human body also contains networks of blood vessels. Unless otherwise specified, the vein equivalent of arteries generally share the same name.

Compare the following:

Pulmonary vs. systemic (blood vessels, function, oxygenated vs. deoxygenated)

Arteries vs. veins (structure)

The pulmonary system serves to get deoxygenated blood into the lungs -specifically to the alveoli- where the blood cells can get oxygenated. The pulomanary trunk branches into the pulmonary arteries, which carry deoxygenated blood. After oxygenation, they begin making their way back to the heart, thus being called the pulmonary veins. The systemic system serves to get oxygenated blood throughout the body, with arteries carrying oxygenated blood and veins carrying deoxygenated blood.

Arteries must have thick walls in order to stand through the high pressure of blood that passes through them. They have 3 distinct layers to handle the influx of blood at a high velocity from the aorta. Veins are larger in dimater and are thinner than arteries. They also have valves that allow the blood to move through systematic contractions, and prevent backflow from occuring.

List the structures (specific blood vessels, parts of the heart) that a blood cell would pass by within the circulatory system - moving from the carotid artery all the way back to the aorta.  Include information about where and when the blood is oxygenated and deoxygenated.

Carotid artery (oxygenated) -> Brain (Oxygen arrives) -> Internal Jugular Vein (deoxygenated) -> Superior Vena Cava (deoxygenated) -> Right Atrium (deoxy) -(AV)> Right Ventricle -(Semilunar Valve)> Pulmonary Trunk -> Pulomary Arteries -> Lungs (oxygenated) -> Pulmonary Veins -> Left Atrium -(AV)> Left Ventricle -(SL Valve)> Aorta (oxygenated)

Fetal circulation:  Describe the 3 major modifications of the fetal circulatory system.  What is the purpose of each?

Foramen Ovale : Allows blood to enter the Light Atrium from the Right Atrium through an opening; effectively bypasses the lungs.

Ductus Arteriosis: Allows blood from the Pulomanary Arteries to bypass developing lungs and enter the aorta.

Ductus Venosus: Allows oxygenated blood from the placenta to enter the vena cava and bypass the liver

Is deoxygenated blood blue?

     A common misconception, the concept of blue blood has been around ever since keen observers began exploring the wonders of the cardiovascual system. The reasoning behind this misleading theory seems to stem from the fact that our veins - which carry deoxygenated blood - appear to be blue to us, and thus, their contents musat reflect this stark color. The reality however is far less conclusive. This theory goes under several assumptions, namely assuming that veins are transparent enough to emit the color of the blood they carry, and relies heavily on the concept that it is only oxygen that gives blood its crimson hue.

    Prior to defeating this misleading theory which seems to have alluded many a biology teachers and some students, time should be allotted to discuss the science behind oxygenated red blood. Blood contains millions of hemoglobins which attach to oxygen molecules, releasing them to every individual cell in the body. The oxygen-enriched blood cells are bright red in color due to the oxidation of the iron present in each hemoglobin protein. When the oxygen vacated the hemoglobin, the cell defaults to its original state - dark red. This is why blood drawn into a vacuum (e.g. a syringe)  remains a solid red color, and blood released in oil will remain red despite any contact with oxygen.

     So then why are veins blue? It should be noted that colour is not necessarily a property, but just wavelengths of light being reflected towards the observer. Human fat allows only blue light to penetrate deep into the veins, and the deoxygenated blood only further absorbs the darker wavelengths. The end result appears to be a dark and blue vein that appears to carry bluish blood. Any meat aficionado will be able to tell you that veins are not distinguished from other blood vessels, and instead appear brownish-red in color. 

What are the effects of having only one lung?

A dash of perspective by Rawel Sidhu and Michael Panderla

Although rare, it is possible to be born with only one lung. Such a birth defect can highly increase the infant mortality rate for the child, and it could greatly decrease their chance of survival without proper equipment and specialized ventilation. Victims of lung cancer or lung trauma often require the surgical removal of the effected lung.

Patients with only one lung sharply increase their risk of contracting pneumonia and other lung diseases. Subsequently, lung cancer patients can often find their other lung at risk of cancer or other breathing impediments, thus the usage of a ventilator may be required.

SRxA, a pharmaceutical consulting firm, confirms that"In America alone, it’s estimated that more than 40,000 people have only one lung. And most of them do just fine because the body tends to compensate by making the other lung grow larger."http://srxawordonhealth.com/2013/03/15/life-without-a-lung-and-other-vital-organs/

Interestingly enough, the newly appointed Pope, Pope Francis, has only one lung, which hasn't prevented him from performing his duties as the head of the Catholic Church. Removal of one lung itself hasn't been all to modern, as pneumonectomy has been around since the 1950's, where the lack of antibiotics made post-surgery fatalities all to common. Nevertheless, with the influx of modern medicine, the removal of one lung no longer carries with it the death sentence it once held, and with the advent of even more discoveries in science, the outlook for patients needing the removal of one lung seems brighter than ever.