EKG Lab

In class, we were instructed to perform a lab that deals with the human EKG(electrocardiogram). We hooked up electrode tabs onto our arms(2 each arm, one bicep and one on the forearm) and monitored our heart beats. I will show you mine, and describe what an EKG measures exactly.

As you can see, fairly normal heartbeat, and regular beat intervals. Now, I will show you another picture I found on the internet that will actually label and describe what each wave in an EKG is called.

As you all can see, each wave has its own label, even the flat parts are noticed as segments. I will break each part down and define them so you get a better idea of what each name is specifying. 

Feature	Description	Duration
RR interval	The interval between an R wave and the next R wave: Normal resting heart rate is between 60 and 100 bpm.	0.6 to 1.2s
P wave	During normal atrial depolarization, the main electrical vector is directed from the SA node towards the AV node, and spreads from the right atrium to the left atrium. This turns into the P wave on the ECG.	80ms
PR interval	The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. The PR interval reflects the time the electrical impulse takes to travel from the sinus node through the AV node and entering the ventricles. The PR interval is, therefore, a good estimate of AV node function.	120 to 200ms
PR segment	The PR segment connects the P wave and the QRS complex. The impulse vector is from the AV node to the bundle of His to the bundle branches and then to the Purkinje fibers. This electrical activity does not produce a contraction directly and is merely traveling down towards the ventricles, and this shows up flat on the ECG. The PR interval is more clinically relevant.	50 to 120ms
QRS complex	The QRS complex reflects the rapid depolarization of the right and left ventricles. They have a large muscle mass compared to the atria, so the QRS complex usually has a much larger amplitude than the P-wave.	80 to 120ms
J-point	The point at which the QRS complex finishes and the ST segment begins, it is used to measure the degree of ST elevation or depression present.	N/A
ST segment	The ST segment connects the QRS complex and the T wave. The ST segment represents the period when the ventricles are depolarized. It is isoelectric.	80 to 120ms
T wave	The T wave represents the repolarization (or recovery) of the ventricles. The interval from the beginning of the QRS complex to the apex of the T wave is referred to as the absolute refractory period. The last half of the T wave is referred to as the relative refractory period (or vulnerable period).	160ms
ST interval	The ST interval is measured from the J point to the end of the T wave.	320ms
QT interval	The QT interval is measured from the beginning of the QRS complex to the end of the T wave. A prolonged QT interval is a risk factor for ventricular tachyarrhythmias and sudden death. It varies with heart rate and for clinical relevance requires a correction for this, giving the QTc.	Up to 420ms in heart rate of 60 bpm
U wave	The U wave is hypothesized to be caused by the repolarization of the interventricular septum. They normally have a low amplitude, and even more often completely absent. They always follow the T wave and also follow the same direction in amplitude. If they are too prominent, suspect hypokalemia, hypercalcemia or hyperthyroidism usually.[28]
J wave	The J wave, elevated J-point or Osborn wave appears as a late delta wave following the QRS or as a small secondary R wave. It is considered pathognomonic of hypothermia or hypocalcemia.[29]

I added a graph that was already made so I wouldn't have to type it myself, but these are all correct facts about the EKG. I will label the internet site after if you care to learn more about the names of the waves, intervals, or segments. Remember, not everybody will have the same EKG reading, in fact, nobody probably will. The same  EKG reading would be as rare as finding the same DNA shared with somebody, if not even more rare! If you look above on the graph it labels how long each interval lasts. As you can see in the EKG labeled picture, the PR segment is the segment that is the shortest, lasting only half a second at most! Think about it, how many people are going to have the same heartbeat rhythm, especially when it is measured as precise as milliseconds? Thank you for taking the time to read my blog, I hope it was somewhat useful to all of you that follow my blogs!

Sites Used

http://en.wikipedia.org/wiki/Electrocardiography

http://www.webmd.com/heart-disease/electrocardiogram

Sheep Brain Dissection

I made a powerpoint presentation about the sheep brain dissection lab. the presentation turned out pretty well, with definitions, procedures, and pictures in the powerpoint, I should have made it look understandable. You can check it out here

Heart Dissection/ Heart Labeling Test

On Valentines Day, we were assigned a lab to dissect different hearts, this way we can see the difference in size, and the thickness of the heart walls for different animals. We dissected three different hearts, a sheep, pig, and cow heart. Obviously they were all different sizes, but I will add pictures and dimensions as well. I lost my pictures, but I asked Tiffany, since we both did the same lab and had the same dimensions she said it would be fine if I used her pictures since I am doing a separate blog. I will label the dimensions of the different parts of the heart, for each heart we dissected.

Cow Heart:

Right Atrium: Diameter 3.1 cm

Right Ventricle: 2.9 cm

Right Outer Wall: Thickness 1.6 cm

Aorta: 2.3 cm

Pulmonary Trunk: 3.1 cm

Left Atrium: Diameter 4.7 cm

Left Ventricle: Diameter 3.1 cm

Left Outer Wall: Thickness 3.3 cm

Pig Heart

Right Atrium: Diameter 3 cm

Right Outer Wall: Thickness .5 cm

Aorta: 2.5 cm

Left Atrium: Diameter 5 cm

Left Ventricle: Diameter  5.7 cm

Left Outer Wall: Thickness 1 1/4 cm

Sheep Heart

Right Atrium: Diameter 4 cm

Valve: Diameter .5 cm

Right Outer Wall: Thickness 1.2 cm

Aorta: 1.6 cm

Left Atrium: Diameter 4 cm

Left Outer Wall: Thickness 2 cm

Left Ventricle: Diameter 1.3 cm

As you can tell, each heart will be bigger for the bigger animal, this is because there is more blood that needs to be pumped through the body, and more blood will go through the heart faster. Therefore, the cow heart has thicker walls than the human, sheep, or pig heart. The circulatory system easily plays one of the most important roles in any living organism. 

I used a youtube video in my last blog, and I am going to use another one from the same guy. He is very knowledgable, detailed, and gets straight to the point when it comes to the topic for his videos. The video is called How Blood Flows Through the Heart. I highly recommend watching this video if you are interested in further details about the circulatory system. 

This is the heart test we were assigned in class. Even though this is Tiffany's picture, I got the OK from her to use it because we took a test and did a lab on the same topic. I also had to memorize the same parts on the heart. We were told to memorize as many parts as you can about the human heart, and label them on the picture. I got a 100%!! I was very happy and thought I did good memorizing 22 parts in about 15 minutes. The human heart is truly amazing! I would have had no idea that the heart had so many parts, but anatomy class has transformed me into an educated man! 

As you can see in the picture, all of the parts are labeled, but don't really explain how exactly the circulatory system works(steps). So, I found the best already created website I could for you so you can read it if you are willing to learn about the steps for the circulatory system. The only reason I didn't create a blog on how the circulatory system works is because to be completely honest, I am not 100% sure, or a medical professional so I will leave it to them to guide you through the steps. The page is actually called Introduction to the Circulatory System.

How Do Our Senses Work?

To understand senses, you first have to understand the outer layers of the human body, such as skin. Skin is basically a protective outer layer for your body. But, it helps in so many ways! 5 very important functions of the skin are:

1. Protection against disease
2. maintaining body temperature
3. waste exchange
4. formation of vitamin D
5. Sensory response 

A FAQ(frequently asked question) I receive from many people is how do we feel touch, pain, etc.? Well, there are many parts of the human body that are working to control your senses. First off, your nervous system is what controls feeling. That is why when you feel something really hot, you don't even think about pulling your hand off, you just do it. That is because your body is sending messages telling you to remove your hand from the hot object before your reflexes even process whats going on. The nervous system is a network of cells called neurons that transform information the form of electrical signals.  The human brain has around 100 billion neurons. The signals are sent from the brain, down the spinal cord, and carried throughout the body. If you are interested in getting more detail from this topic, you can go to this website about your nervous system to get more specified details.

     Next, we can talk about how the brain originates touch, and what messages are sent throughout the body to register touch. The picture above is the visual image I get when I think about senses, because the brain sends the messages down the spinal cord. You have two cortex's that are meant for two different types of feelings in the brain. The motor cortex, and the somarosensory cortex. The motor cortex is the part in the brain's cerebral cortex where the nerve impulses originate that initiate the voluntary muscle activity. I found a video on youtube that was probably one of the most direct and informative videos I have ever found while researching for an assignment. The video is a general overview of how our senses work. Thank you for taking the time to read my blog post, I hope it was somewhat helpful to all of you readers!

Virtual Cardiology Lab

Recently, we were assigned to perform a virtual cardiology lab from Howard Hughes Medical Institute(HHMI). The purpose of this assignment is to focus on heritable diseases of the heart, and what you would do if you were a cardiologist. Actually, you aren't the cardiologist, you are the assistant. HHMI performed the lab this way so you could see what the cardiologist does and how you have to assist him while examining the patients heart. This blog is just an opinion page to see what I liked about the lab, and what I thought about it. I won't exactly explain the lab, because you can take the virtual lab yourself and see what you think about it. Personally, I think the lab was easy to perform because you get told what steps to perform. But, if I was a cardiologist I would make sure I was completely comfortable with my patients and diagnosing problems because their life is basically in your hands! At a patients point of view, you better believe I would make sure I got the best cardiologist I could find because if there is something wrong with my heart, I want to know exactly what it is, and what exactly I could do to resolve the problem. The lab does however give you a few quizzes to see if you know what you're doing, I won't lie I didn't do very well. But, then again I am a senior in high school and not a cardiologist. This is the dictionary definition of a cardiologist so you all can get a better understanding of their specialties:
Cardiology (from Greek καρδίᾱ, kardiā, "heart"; and -λογία, -logia) is a medical specialty dealing with disorders of the heart (specifically the human heart). The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure,valvular heart disease and electrophysiology. Physicians who specialize in this field of medicine are called cardiologists. Physicians who specialize in cardiac surgery are called cardiac surgeons.
     I also found a good picture that could give a visual image of a cardiologist and how he helps his patients:

I will also add a youtube video about a  cardiologist that you can view here. I would have made my own video but this particular one was more detailed than the rest. Bear through the first 30 seconds, I dont know what exactly they were trying to do with that, but after that the rest of the video should work out for you. Thanks for taking the time to look at my blog!