Anatomy of the Heart: Sheep, Pig, and Cow Heart Dissection

In this lab the class was divided into several groups, and each group dissected either a sheep, pig, or cow heart. After the dissection was complete, each group moved around the room and collected data on all three different types of heart.

1. The basic structure of each heart is pretty much the same throughout each heart specimen. Each heart has four chamber (two atriums and two ventricles) and contains an aorta and pulmonary trunk. The only difference between the hearts is the size of each structure.
2. There were many differences between each heart specimen. The cow heart was very fatty and firm. Both the pig and sheep heart were softer and did not have as much fat surrounding them. Also the overall size each heart and its structures differed from each other.
3. Adaptive reasons for the difference in size would probably be due to the actual size of each animal. A sheep does not need a heart the size of a cow because it is considerably smaller than a cow.

A picture of the cow heart my group dissected. It was the best one. :)

Reflex Lab

Purpose: 

To see the difference between voluntary and involuntary movements of the body. Why are reflexes faster than voluntary movement?

Materials:

• Computer
• Reflex Hammer
• Accelerometer 
• Logger Pro
• Electrode Tabs

Procedure:

1. In this lab we recorded different people's reflexes. First, two electrode tabs were placed on the subject's legs, across the muscle.
2. The reflex hammer, with the accelerometer strapped to it and plugged into the computer using Logger Pro, was hit against the desk. As soon as the subject heard the hammer being hit, they were to voluntarily kick their leg.
3. The next test was just a simple reflex test. The reflex hammer was used to hit the subject's reflex, and it was recorded on the computer.
4. Next, the subject's reflexes were recorded while resistance was happening in another part of the body. The subject locked their hands together and tried to pull them apart as hard as they could. During this time their reflexes were being tested and recorded.
5. The final test was another simple reflex test. The data was taken right after the resistance test, expect the subject was to relax and not have resistance.

Data/Analysis :

This is a graph of the average time our test subject's reflexes took. In the resistance tests it is shown that with resistance the subject's reflexes were much slower than without resistance. The first bar shows that the voluntary test took much longer than the involuntary test. 

• In the voluntary test the subject kicked their leg an average of .426 seconds after they heard the sound of the hammer hitting. While in the involuntary test, it took an average of .076 seconds for the leg to react after being hit with the reflex hammer. The difference in time is due to the actions in the body. In the voluntary test the brain had to process the hitting of the hammer before the subject could kick their leg. However, in the involuntary test, a circuit from the leg to the spinal cord was used, kicking out the use of the brain completely. This made the action of the involuntary test much faster because it was an automatic response, without the need to travel all the way to the brain and back to the leg.

History of the Brain

History of the Brain on Prezi

Neurophysiology Lab

The Virtual Neurophysiology Lab

Hypothesis: 


The purpose of this lab is to observe the electrical activities of neurons while stimulus is delivered. I believe that the electrical activities of a single neuron will be affected more by a stronger stimuli versus a weaker stimuli. 
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Materials:

• Feather
• Probe
• Forceps
• Scissors
• Pins
• Scalpel 
• Dissection Tray
• Leech Tank
• 20% Ethanol
• Leech Tongs
• Dissection Microscope
• Micromanipulator
• Oscilloscope
• Leech

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Procedure:

1. Use the leech tongs to place the leech in 20% ethanol solution to anesthetize it.
2. Pin the leech dorsal side up through the anterior and posterior suckers onto the dissection try. 
3. Use the scissors to make a cut in the skin. Cut along the mid-line on the dorsal surface. Make sure not to damage deep structures.
4. Use forceps to carefully pull the skin along the cut and pin down the left and right halves of the skin to each side. This way the leech is pinned open, and its innards are exposed.
5. Carefully remove the internal organs in order to expose the nervous system.
6. Us the scalpel  to make two parallel cuts across the animal. Make sure the removed strip contains a ganglion. Use the forceps to flip the skin over, and pin it so that the outer skin in facing upwards.
7. With a very fine scalpel cut the sinus, and using the forceps move the sinus until the ganglion is exposed. You will now be able to see individual cells under a microscope.
8. Move the electrode over the ganglion to stimulate the process of penetrating a cell. Keep moving the electrode until you find a cell. 
9. Use the feather (probe or forceps work as well) to push around the skin of the leech. Check if the penetrated cell responds to weak (feather), medium (probe), or strong (forceps) stimulus. 
10. Begin your anatomical investigation. Inject the cell with a fluorescent dye. Now that the cell is dyed, click the UV switch in order to see the dyed cell in UV light. You can now identify the cell by using the Atlas.

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Results: 


There were five different types of cells found, and each of them reacted differently to different stimuli. The Atlas for the lab shows all the different ways each cell reacted to the different stimuli:

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Conclusions: 


Overall, no one stimuli caused the most electrical activity in all five cells. There were cases, such as the N cell, where the strongest stimuli was the only cause for electrical activity. However, in other cells, like the T cell, the weakest stimuli caused the greatest activity. Overall, all the cell types, with one exception, showed some type of activity when one type of stimuli was delivered.

Internal Structure of Skeletal Muscle

The Internal Structure of Skeletal Muscle on Prezi

Chewing Lab