Sheep Heart Dissection Questions

1. The pericardium serves to provide lubrication for the heart and protects against infection. It is the outermost layer of the heart.

2. The biggest difference between veins and arteries is that arteries take blood away from the heart, while veins bring blood to the heart. Veins have valves that prevent back-flow of blood. The veins also have thinner walls. Arteries have thick, muscular walls.

3. The auricles are like a balloon attached to the atria. They fill up with blood also, increasing the holding capacity of the atria.

4. The external structure gets narrower as we go down the heart. The atria are wider than the ventricles. This gives the appearance of the upside down triangle sort of shape.

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7. The chordae tendinae prevent the valve from reopening in response to the pressure lowering in the atrium during ventricular systole. The pressure in the atria becomes much lower, and because things naturally go from high to low concentration, the chordae tendinae and papillary muscles prevent this from happening.

8. The valve is a whitish color, different in texture from the endocardium lining of the chambers. This valve is bigger than the semilunar valves and the tricuspid valve.

9. Semilunar valves prevent back-flow from arteries back into the ventricles during ventricular diastole, and they also maintain the pressure in the arteries so they can effectively push the blood where it needs to go.

10. a) Blood can become backed up in other parts of the body if there is valve disease, causing swelling. If the blood can't get pumped back into the heart, it becomes stuck. b) Left side valve disease can cause tricuspid regurgitation.

11. The chordae tendinae of the bicuspid valve are super stringy, pulled taut with probe causes valve to be open. You can see through the aorta, or where the aortic arch would be.

12. The right side of the heart receives oxygen deprived blood and sends it to the lungs for reoxygenation. Conversely, the left side of the heart receives the oxygen rich blood from the lungs and sends it to the rest of the body through the left ventricle.

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Unit 3 Reflection

Review: This unit was about cardiovascular health, and how to maintain said health. The circulatory or cardiovascular system is comprised of three parts, the heart, the blood, and the blood vessels. The heart is the basis of operations: all blood in the body comes back to the heart to be reoxygenated and resent back to the body. The structure of the heart plays an important role in its function: four separated chambers operate through contraction and relaxation, called systole and diastole respectively, which pushed the blood out of arteries, particularly the pulmonary arteries and the aorta. The right side of the heart gets deoxygenated blood and sends it to the lungs, and the left side gets oxygenated blood and sends it to the body. The blood itself is comprised of different types of cells and fluid: red blood cells, white blood cells, plasma, and platelets. Blood vessels, like arteries, veins, and capillaries, transport the blood where it needs to go in the body.
Heart disease is caused by atherosclerosis, triggered by excess sugar, excess polyunsaturated fats, excess omega-6, and damaged blood vessels. Focusing on the latter, blood vessel damage occurs when LDL, the "bad cholesterol," sticks to the walls of the blood vessels, lodging itself in the walls. When this occurs, an inflammatory response is triggered, which results in a counterproductive process of creating "foamy" mast cells, creating a plaque in the walls. This plaque can break, which causes a blood clot. This blood clot can either block the blood in the same blood vessel, or break off and travel further in the body, where it clogs up there and causes a heart attack or a stroke. A stroke only occurs in the brain, and can be very fatal. Every minute during a stroke, 2 million blood cells die, making the treatment for strokes very time-sensitive. To promote your own cardiovascular health, maintain a healthy diet, exercise, do not smoke or drink alcohol in excess, and know your family history of hypertension.
Reflect: I am still struggling with differentiating between the different white blood cells. I struggled with the case study activity, which is concerning because that question format is a large portion of the test. Also, without my group members to collaborate with, I probably cannot identify structures on the sheep heart alone. If I had to look at another sheep heart that wasn't the one I was familiar with and hands-on with, I would be beyond confused.
Considering that it is currently past midnight and I'm still mid-study session, my sleep goal from last semester is not going so well. However, I was able to catch up on some of the midterm-stolen sleep over the weekend! These couple of weeks are extremely tough as many deadlines overlap. Most of the units in our various classes tend to end on a similar schedule, meaning that we have weeks of "chill" time and weeks of testing mayhem. This makes it hard as a student to allocate my time to all of my classes appropriately, and maintain my work schedule. In general, I'm a focused person, so I know that it's not lack of focus contributing to any poor marks, but rather just lack of time or biological ability to function. I do try as hard as I can.
Going back to the unit, a surprisingly fun activity was the dissection! I entered the activity with a negative mindset, intending to only take notes, but I was soon "two-glovin' it" and fully immersed, poking and prodding the heart with gusto. I'm happy with myself for pushing my learning to another level, despite my prior reservations.