The Heart Beat Explained

The Heartbeat Explained. (Left to Right)

Often times, we see this picture above in a much more colored and “cool” layout. But have we ever thought about what it really means? Yes, the waves are the heartbeats, but what exactly does every little hill and bump stand for? There’s a reason why the onomatopoeia for the heart should be ba-dump, ba-dump instead of thump, thump (or somewhere along those lines). Hopefully, this will explain why the sound should be seen as two syllables instead of one.

When blood enters the both atria via the superior and inferior Vena Cava and the Pulmanary Veins, blood is able to flow into the atria because it is in a relaxed state, also known as Atrial Diastolye. As of this time since there is also no blood in the ventricle, it is also relaxed and called Ventricular Diastolye. This state of relaxation in the right atrium and ventricle is the first flat line.

The first little hill is known as the P-Wave and that bump is due to the contraction (systole) of the atria. This contraction causes blood, that was originally in the atria, to flow into the ventricles. At this moment, the right ventricle is still relaxed which enables the blood to flow into it. Overall, this is called Atrial Aystolye and Ventricular Diastole. This wave is the first syllable of the heartbeat: ba-dump.

The next segment is another flat line. This represents a slight pause or a delay in the pacemaker’s signal by the AV Node. Why is the signal delayed? The command to contract originates and is controlled by the pacemaker. If that signal is spread through the whole heart, all four chambers will contract simultaneously, resulting in no movement of blood. By delaying the signal, the atria can contract to ensure blood flow. After that contraction, the ventricles then receive the contraction signal. This delay is the reason for the “two syllable” heartbeat.

The next big spike is called the QRS Wave and is mainly due to Ventricular Systole. Why is the wave greater than the rest? It’s size is primarily due to the left ventricle’s contraction. The wave is pretty grand compared to the other waves because of the power and strength of the left ventricle’s contraction. It has to be strong enough to pump all of the blood to the rest of our body. Of course, the right ventricle contracts as well, but it is not as powerful since it only pumps un-oxygenated blood to the lungs. In addition, the atria relax simultaneously while the ventricles contract. This Atrial Systole is called the M-Wave. However, it cannot be seen because it is hidden by the left ventricle’s contraction. Although it is masked by the contraction and the M-Wave cannot be seen, it does not mean that it does not happen. The QRS Wave is the reason for the second syllable of the heartbeat: Ba-Dump.

The last little hill is called the T-Wave, due to Ventricular Diastole. Now that the ventricles have pumped out its blood, they can now relax, allowing the heart to be ready to start its contraction cycle once again.

-This Cardiac Cycle all takes place in a matter of .8 seconds. Fascinating, isn’t it? In a quick little summary, the heartbeat should be seen as two syllables because of the two different contractions of the atria and the ventricles. If the beat would be one syllable, that would be a problem for our circulatory system.

-Nicole Acnam

Due to the fact that I’ve been squished under a pile of work and studying, I haven’t been able to post as much biology things as I wanted. Now that it’s Friday, I have a little time to do so. So, I found myself wondering what I should post about, and then it hit me, while I was eating a dumping. After all, this also works as a great review tool for me.

The Digestive system is primarily broken down into three parts: Ingestion, Absorption and Elimination. 

Ingestion, of course, begins in the mouth. As we know, we chew and cut the food we ingest with the help of our teeth. That act is called mastication. By breaking the food down into smaller pieces, its surface area is increased. Once that is done, saliva coats the food. Saliva contains salivary amylase which breaks down amylose and starch, killing some the bacteria and acting as a buffer to raise the pH of the food in oder to make it less acidic. In turn, our tongues shape the food into a ball, called the bolus, and pushes it into our throat, also known as the pharynx. By peristalsis, the pharynx contracts, moving the bolus downwards. This course eventually becomes the esophagus which also performs peristalsis. Once the bolus reaches a certain area before entering the stomach, it passes through the cardiac sphincter which acts like a gateway into the stomach. Its main function is to prevent the stomach acid from reaching the esophagus.

The Digestion phase begins once the bolus reaches the stomach where it mixes with gastric acid, also known as stomach acid, that has a pH of 2. In addition, the stomach produces pepsinogen which turns into pepsin in an acidic environment. It is strong enough to kill bacteria, break down proteins, and also powerful enough to burn through the stomach’s walls. How is gastric acid contained in the stomach? Well, the stomach lining constantly secretes mucus for protection, but they still undergo mitosis to regenerate cells that die off. After the adventure in the stomach, the bolus is now called acid chyme. The contents pass through the pyloric sphincter—yet another gateway— into the small intestine. The first portion of the small intestine is the duodenum in which acid chyme mixes with pancreatic acid, a buffer that counters the acidity of the acid chyme, and bile, produced by the liver and stored by the gal-bladder. As the acid chyme and its mixture travel through the rest of the small intestine, the broken down nutrients are absorbed by its villi, allowing the blood vessels that surround the small intestine to absorb the nutrients. These blood vessel converge into the hepatic portal that connects to the liver where most of the nutrients are stored into and the rest are given to the body.

Once the contents reach the large intestine, Absorption begins. As you recall, food was mixed with gastric acid, bile and pancreatic juice, most of which is really made out of water. If our bodies would let all of that pass through and straight out of us, then we would undergo massive water loss. Therefore, in order to avoid dehydration, the large intestine reabsorbs the water that was used, making the contents more solid. The large intestine is also home to E. Coli—the good kind, yes there are good ones— that take some of the waste material and produce vitamins that benefit us. However, they also produce methane… which is farting gas. Overall, it’s a mutualistic relationship where both organisms benefit. By the end of the absorption stage, we have ourselves a good, solid piece of feces. (:

-Nicole Acnam

Memories are, in fact, chemical reactions.

All the images, thoughts, and sounds that we recall are catapulted by numerous, if not millions, of ions colliding with each other. How is it possible that a hydrogen ion colliding with a sodium one (using this for an example sake since there are many possibilities) bring fourth memories of childhood, of a loved one or what we wore last Tuesday? How can something so simple result in such complex results? Even more so, why do our brains choose to remember that one exact moment out of the other millions we have or will have?

-Nicole Acnam

Fruits are plant ovaries.

In a literal and biological sense. Fruits are one of the adaptations of plants that have developed and used as a way to disperse their seeds. Simply put, flowers are beautiful and are scented to attract pollinators, such as bees who carry around pollen from previous flowers that they’ve gathered nectar from. When bees land on flowers, they unconsciously give off pollen, which carry an average amount of two sperm cells per pollen grain.When the pollen lands on the stigma of the flowers(the surface of the female portion of the flower), the pollen is taken down into the area in which the flower carries an ovary. Once the sperm of the pollen meet with the ovary, the flower begins to develop into a fruit.  The fruit itself is used as an attraction factor to animals. Eating the fruit also means ingesting the seeds that the fruit contains. Seeds are made to survive the acidity of an animals stomach. After an animal finishes eating the fruit, they are likely to travel. Once they digest their food and release their feces, the seeds are also set free and will develop into flowers where ever the animal lays its bowels. 

-So, for you that have eaten fruits today, be proud to know that you have just eaten a plant’s ovaries!

-Nicole Acnam

Why is the water blue?

No, it is not blue because the sky is blue as the common myth says it to be. Rather, the color of the ocean begins with the fact that light is compromised of many different colors of the color spectrum such as purple, blue, green, yellow, orange and red (listed by increasing wavelength). In the bottom of the ocean lies complete darkness, also known as the absence of light. The deeper you go into a body of water, the less light there is. In a way light is “filtered” and this is also known as light attenuation. Light gets “filtered” due to water molecules absorbing the colors with longer wavelengths (yellow, orange and red). This allows colors like blue, and even green, to penetrate the waters for a longer period of time and be visible to the eye.
-Nicole Acnam

Why more males are color blind.

Being color blind is a recessive trait that needs allele combinations of two recessive alleles such as “aa.” That combination is the only way recessive traits will be expressed in the individual’s phenotype. When a recessive allele is paired with a dominant one (Aa) then the recessive allele will not be expressed—but rather suppressed— by the dominant allele because it is, well, dominant.  Sadly, being color blind is a sex-linked gene. As it is commonly known, females have the combination of “XX” (two X chromosomes) while males have the “XY” combination (one X and y chromosome). The gene for being color blind is located on the X chromosome. For females, since they have two of these, the X chromosomes must both carry the recessive allele in order for that female to be color blind (aa). Most of the time females are less likely to be color blind because one of those X chromosomes, or even both of them, carry the dominant allele, saving them from being color blind (this can result in an AA or Aa allele combination). For males, however, they only have one X chromosome and it is not the same as a Y chromosome. So, if the X chromosome has the recessive allele, they have no choice but to express it because there is no other allele that would dominate or “suppress” it.


-Nicole Acnam

Anaphase

I briefly went over this yesterday with my old cards for Biology. Probably one of the most significant facts about Mitosis happens through Anaphase. The kinetochore spindle fibers attach to the chromosomes but they do not pull on it. Instead, the kinetochores of the chromosomes use the mitotic spindle fibers has a guide to move themselves to the opposite poles of the cell.


-Nicole Acnam

When A Fish Is Taken Out of the Water

Please don’t say that it could die because there isn’t enough oxygen in the air for them. Commonly, that is what people think. The fact about this myth that is wrong is, that there really is actually more oxygen in the atmosphere than in the ocean or any body of water. Fishes, in fact die from dehydration first and then suffocation. The reason for this is because fishes receive oxygen through their gills via counter-current flow. Their gills are loose and flow in water which allows them to accomplish that. When taken out of their environment, their gills close up, defeating their ability to receive oxygen since they lack lungs. It’s like when you wear regular clothes and dive into the swimming pool—they float around in the water. The instant you get out, however, they cling to you like glue; a feeling that I find the most unpleasant.


-Nicole Acnam

The Small Intestine

On a common note, when asked, “What is the difference between the small and large intestine?” what do people usually answer? This question can actually be a bit tricky because the small intestine is not quite small at all. In fact, length wise, the large intestine can barely keep up with the six meters that make up the small intestine. Then why is it called the small intestine? Its name was assigned due to the diameter or width of the intestine. The small intestine can be thought of as narrow tube while the large intestine is much wider and has a larger diameter that can be thought of as a tunnel.


-Nicole Acnam

How Enzymes Work.

You are probably familiar with this term from any science class you ever took. As it is commonly known, enzymes speed up chemical reactions. But, have you ever thought of how they do such a thing? They do this by lowering the amount of activation energy that the reaction needs. Activation energy is the amount of energy that a reaction requires in order to take place. Naturally it takes time to accumulate enough free energy to catalyze the reaction. Let’s say that a reaction needs an x amount of activation energy. Instead of waiting a minute or so for free energy to gather, you can add an enzyme, lowering the activation energy amount to x-5 thus taking a significantly less amount of time for the reaction to occur.

Memories are, in fact, just chemical reactions.

All the images, thoughts, and sounds that we recall are catapulted by numerous, if not millions, of ions colliding with each other. How is it possible that a hydrogen ion colliding with a sodium one (using this for an example sake since there are many possibilities) bring fourth memories of childhood, of a loved one or what we wore last Tuesday? How can something so simple result in such complex results? Even more so, why do our brains choose to remember that one exact moment out of the other millions we have or will have?


-Nicole Acnam

Imprinting

Imprinting

This term isn’t really what people think it is due to Twilight’s allusion to this term. Imprinting is not claiming your soul-mate like Jacob does in the Twilight series. Instead, imprinting is actually a short period of learning for a newborn, not limited to human babies of course. This type of learning allows newly born animals to recognize their parents’ smell and sound of their voice—because they have horrible sight— shortly after they are born since parents are usually the first ones on the sight. Konrad Lauren was an ethologist who studied imprinting. He collected abandoned duck eggs and took care of them. When they were about to hatch, he was there waiting patiently. The result? The new ducklings followed him around and treated him as if he was their mother duck. 

-Nicole Acnam

"You have beautiful features!"

That phrase is actually incorrect in a sense that everyone actually has the same features. We all have eyes and noses don’t we? If you’re going to compliment someone on their “features” what you are actually referring to is their innate traits. Features are the things themselves such as eyes, lips, noses, anything on our body that we have in common with everyone else. Now, the types of eyes—blue, brown,hazel, you name it— are called traits. Traits are different forms of features. Therefore, the phrase stated above should really be, “You have beautiful traits!” Because the combination of traits that individuals possess are what makes them unique.


-Nicole Acnam

Sight

Our ability to see is beautiful, isn’t it? We can see wonders, colors and others. With vision, we make memories. It’s one of our most glorious senses and the one that we depend on the most. Sight is such a gigantic portion of our life. So then would it be a bit shocking that seeing our loved ones, friends and the world would not at all be possible if we didn’t have this thin layer of film in our eyes called the retina? Such a big portion of our lives depend on such a small film that isn’t any where close to being as big as our palms.

Now, I know that there are many components to our eye sight. But the retina is probably the most important because it is where light directly has a chemical reaction with our eyes. This is just in my opinion, since artificial lenses are available now as opposed to artificial lenses.

-Nicole Acnam

Fruits Are Plant Ovaries

In a literal and biological sense. Fruits are one of the adaptations of plants that have developed and used as a way to disperse their seeds. Simply put, flowers are beautiful and are scented to attract pollinators, such as bees who carry around pollen from previous flowers that they’ve gathered nectar from. When bees land on flowers, they unconsciously give off pollen, which carry an average amount of two sperm cells per pollen grain.When the pollen lands on the stigma of the flowers(the surface of the female portion of the flower), the pollen is taken down into the area in which the flower carries an ovary. Once the sperm of the pollen meet with the ovary, the flower begins to develop into a fruit.  The fruit itself is used as an attraction factor to animals. Eating the fruit also means ingesting the seeds that the fruit contains. Seeds are made to survive the acidity of an animals stomach. After an animal finishes eating the fruit, they are likely to travel. Once they digest their food and release their feces, the seeds are also set free and will develop into flowers where ever the animal lays its bowels. 

-So, for you that have eaten fruits today, be proud to know that you have just eaten a plant’s ovaries!

-Nicole Acnam

Learning To Walk

This ability is actually innate. It’s passed down; it is in our genetics to walk on our two feet. Therefore, babies do not actually “learn” to walk. They already know how to do so because that skill is actually inherited. They perform this action when their muscles have developed enough, which is why they do not walk when they are first born. When they begin to walk, they are just getting their newly developed muscles to work properly, like conditioning. The brain already knows that action. it’s just a matter of getting its soldiers to listen to its commands.