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!

HHMI Virtual Neurophysiology Lab

Thanks to the Howard Hughes Medical Institute, it is possible to perform a neurophysiology lab online now! The specimen that was used was actually a leech. The website gave step by step instructions so even a child could perform the lab, but also gave notes and details about what exactly you were doing so it could be used at even a college level! All of the lab tools needed are included, such as: microscope, scalpel, probe, forceps, scissors, pins, dissection tray, leech tank, 20% ethanol solution to sterilize the leech, tongs, a micro manipulator, and an oscilloscope. The steps in this lab were:

1. Anesthetize the leech in the ethanol solution.
2. Pin the leech side up dorsal side up on the anterior and posterior suckers.
3. Use scissors to cut the skin along the mid line on the dorsal surface. 
4. Use the forceps to pull the skin apart.
5. With the probe, remove the insides of the leech.
6. Notice that there are many swellings up and down the sinus. These contain the segmental ganglia of the nervous system. To make one of them accessible, first we cut a window in the body wall underneath a ganglion, taking care not to damage the nerve cord or any attached nerves in the process.
7.  cut a window in the body wall underneath a ganglion, taking care not to damage the nerve cord or any attached nerves in the process. 
8. Isolate a section of the animal by making 2 parallel cuts across the animal, but sufficiently separated so that the strip you remove contains at least one ganglion. 
9. Then, with forceps, flip the piece of skin over so that the outer skin is now face up. Pin the skin down. 
10. Cut the sinus with an ultra fine scalpel and using fine forceps, carefully tease apart the sinus to expose the ganglion. Individual cells can now be viewed under the microscope. 
11. In reality, you would only use the scalpel here only if you are extremely good at microdissection. It's very difficult to cut just the sinus without accidentally damaging the ganglion underneath, but hey, we are all perfect in cyber land. Normally, this is done with a pair of very fine forceps.
12. Finally, you will have to probe and identify ganglion sensory cells. If you plan on doing this, you will need the micromanipulator, and background knowledge of electrical equipment so you can follow this procedure as professional as possible! 

     The reason I listed this is to give my blogger followers a quick lab and procedures so they dont have to go surfing on the internet to find everything I just described. The reason anybody would perform this lab would be to get a better understanding on how to measure electrical impulses and observe the structure of neurons in a model like the leech.
     My personal opinion of this virtual lab is definitely positive feedback! This lab was a great way to dissect an organism, it was really helpful for those who don't have the money for the lab equipment, or just don't have the stomach to dissect organisms. Overall, I liked everything about this lab. 

     Below is a very short video of how a neuron or nerve cell receives impulses and passes them on to other cells. It is actually pretty fascinating!

Anatomy of a neuron(Nerve Cell)

Neuromuscular Junction

     Kendra and I made a poster about NMJ (Neuromuscular Junction) Here is a page about NMJ. We will also post a picture of our own poster: 

NMJ is a specialized synapse. Its job is to transmit the electrical impulses throughout the body. It does so through the motor neuron nerve terminal. Once it leaves there, these impulses are sent all over the body. There are 7 steps for sending the electrical impulse, I will quickly describe all of them for you:
Step 1: There is an electrical impulse signal that has to reach the nerve terminal in the "presynaptic" region.
Step 2: When the impulses reach the nerve terminal, they activate calcium channels.
Step 3: The increase the calcium concentration will have to trigger the fusion of the synaptic vesicles with the nerve terminal membrane.
Step 4: Once this is fused with the nerve membrane, the vesicles will release its contents into the extra cellular space, this extra space is known as the "synaptic cleft."
Step 5&6: Acetylcholine binds to its receptors. It then will open ligand-gated channels. Next an end plate potential will be created.
Step 7: The final step, Acetylcholinesterase will degrade the acetylcholine so that the process can start over again and new acetylcholine molecules can be produced. 

Bone Structure

     If you like to study the human skeletal system, you will probably want to start with the support of the body. That would be the bones and bone structure. The best example I could start for beginners would be the femur. This bone is the longest and straightest single bone in the human body. It is also the strongest. If you break this bone, dont plan on walking again until it is completely healed or major problems could occur! the picture below is a human femur.

     Now, not all bones are solid in the human body. There are two specific types of bones when thinking of the structure. Cortical and Trabecular bones. Cortical bones are the hard and white bones you see that are the harder of the two. Trabecular bones are the honey comb looking holes inside the bone and are actually filled with marrow. Personally, I dont understand why the holes are considered "bone" but that is just me. It is important for bones to be strong to support our body weight and in some cases provide protection such as the skull and ribs. However, they must also be light enough to make movement possible. A long bone consists of several sections:

• Diaphysis: This is the long central shaft
• Epiphysis: Forms the larger rounded ends of long bones
• Metaphysis: Area between the diaphysis and epiphysis at both ends of the bone
• Epiphyseal Plates: Plates of cartilage, also known as growth plates which allow the long bones to grow in length during childhood. Once we stop growing, between 18 and 25 years of age the cartilage plates stop producing cartilage cells and are gradually replaced by bone.

     Just to make sure you all understand this bone structure a little better, I will add a youtube video just for a little extra grasp of the concept! I will warn you now it is 8:42 minutes long but it is very informative and also explains everything about the picture above as well. 

http://www.youtube.com/watch?v=TnY6l9hMOew