Heart Dissection Lab

Q1: What is the purpose of the pericardium?

The pericardium is a double sac of serous membrane that secretes a fluid to lubricate the heart and reduce friction. It also protects the heart.

Q2: Observe the blood vessels connecting to the heart.  How do arteries differ from veins in their structure?

Veins have thinner walls than arteries and are also one way valves (prevent back flow of blood). Arteries carry blood away from the heart to the tissue while veins carry blood to the heart from the tissue. Veins store the most blood volume in the body. Arteries are elastic and contractile.

Q3: Place your finger inside the auricle.  What function do you think the auricle serves?

The auricle feels rough when we placed our finger inside the auricle. Auricle increases blood capacity and volume in the atrium and also collect blood.

Q4: Observe the external structures of the atria and ventricles.  What differences do you observe?

The right atria is the upper chamber that receives oxygen deprived blood. The right ventricle a lower chamber that discharges blood. The left atria is the upper chamber that receives oxygen rich blood. The left ventricle is a lower chamber that has the thickest wall. In structure, the ventricle has thicker walls and takes up more space.

Q5: Find and Describe the following structures in the heart:
1. Coronary Sinus: a wide venous channel that receives blood from the coronary veins and empires into the right atrium of the heart.
2. Inferior Vena Cava: (carries blood from lower body) a large vein and empties into the right atrium of the heart. The superior vena cava carries blood from upper body.
3. Tricuspid Valve: Located between the right atrium and right ventricle; it prevents back flow of blood into the atrium

Q6: Draw a picture of the tricuspid valve, including chordate tendinae and the papillary muscle.

Picture:

Q7: Why is the “anchoring” of the heart valves by the chordate tendinae and the papillary muscle important to heart function?

After the right ventricle contracts, the blood pressure pushes on the tricuspid valve, which stops the blood flow to the right atria. The job of chordae tendinae is to make sure the side edges of the valve don’t get pushed into the atria. It is important because it stops the valve from pushing blood in the wrong direction.

Q8: Using pictures and/or words describe what you see (bicuspid valve)

Picture:

The probe in this picture points to the bicuspid valve, which is between the left atrium and ventricle

Q9: What is the function of the semi-lunar valves?

The Semilunar valves prevent arterial blood from re-entering the heart. Two types are the pulmonary semilunar valve and the aortic semilunar valve.

Q10: Valvular heart disease is when one of more heart valves does not work properly.  Improperly functioning heart valves can lead to regurgitation, which is the backflow of blood through a leaky valve.  Ultimately this can lead to congestive heart failure, a condition that can be life threatening.

If the valve disease occurs on the right side of the heart, it results in swelling in the feet and ankles.  Why might this happen?

The ventricles are not strong enough to pump blood against gravity from your toes and feet. Blood is not able to function normally and back flow occurs.

If the valve disease occurs on the left side of the heart, what complications would you expect to see?

If the valve disease occurs on the left side of the heart, not enough blood would be pumped. Therefore, swelling would occur.

Q11: Using pictures and/or words describe what you see (left/right coronary arteries, left semilunar valve (3 cusps), chord tendinae of bicuspid valve, and pillar muscle of the bicuspid valve)

Picture of left ventricle:

a. Entrance to the left/right coronary arteries: The coronary arteries supply blood to the heart.
b. Left (aortic) semilunar valve (3 cusps): The aortic semilunar valves prevent arterial blood from re-entering the blood.
c. Chordae Tendinae of the Bicuspid Valve: Chordae Tendinae are tendons attached to cusps of valves.
d. Papillary Muscle of the Bicuspid Valve: They provide "muscle power" and they pull on the chordae tendinae to open/close valve.

Q12: Describe how the left and right sides of the heart differ from each other.

The right side of the heart pumps deoxygenated blood to the lungs. The left side of the heart pumps oxygenated blood to the aorta and out to the rest of  the body. Also, the right side of the heart has thinner walls while the left side of the heart has thicker walls.

Q13: Draw and label all structures visible in the interior of the cross-section.

Picture:

Unit 3 Reflection

This Unit was about the circulatory system, the respiratory system, and cardiovascular diseases such as stroke and heart disease. The circulatory system transports materials needed by the cells and removes waste materials from the cells. The respiratory system works with the circulatory system to exchange gas. The cardiovascular system works by the pulmonary circuit (O2 deprived) and the systemic circuit (O2 rich). Blood first enters the right atrium from the inferior and superior vena cava. It then passes through the tricuspid valve and enters the right ventricle. It passes through the pulmonary semilunar valve to the pulmonary trunk to the pulmonary arteries and out to the lungs. Lungs then exchange carbon dioxide for oxygen. In the systemic circuit, pulmonary vein returns blood to heart via the left atrium. It passes through the bicuspid (mitral) valve and enters left ventricle. Lastly, passes through aortic semilunar valve into aorta and out to body. Veins carry blood to the heart from the tissues while arteries carry

blood away from the heart to the tissue. 

Cardiovascular health refers to the health of the heart and blood vessels. Lack of exercise, being overweight, smoking, metabolic syndrome, diabetes, high blood pressure (caused by atherosclerosis), and high cholesterol all cause cardiovascular disease. To promote cardiovascular health, people should control their blood pressure. 40-90% of all stroke victims had high blood pressure before their stroke. To maintain healthy blood vessels, people should exercise, maintain a healthy weight and diet, control blood pressure and cholesterol, prevent atherosclerosis, prevent diabetes, don’t smoke, and minimize stress. I want to learn more about Lung Cancer, Chronic Bronchitis, Asthma, Cystic Fibrosis, Sinusitis, Tuberculosis, Pleurisy, Influenza, etc. because those chronic pulmonary diseases seem very interesting to me. My aunt had lung cancer so I would love to learn more about it and how it can affect someone’s life. I wonder if there has been any medications to prevent strokes kind of like a vaccine.

My weaknesses in this unit were learning the diagram of the heart. I had a lot of trouble understanding the different parts of the heart even though I understood the functions of all the major valves and blood vessels. I enjoyed the heart dissection even though it was very difficult to locate all the parts of the heart. Working in a group helped me with this challenge. This unit was very interesting to me because some of my family members have had heart attacks (they never recovered fully after) so I finally understand what could have caused the disease. I also had trouble studying for this test because I tried many methods to try to understand all the material. I studied with Nimisha the day before to make sure we both understand the topics. I am still having trouble studying because even though I put a lot of effort into my studying, it doesn’t seem to help because I still don’t do good on the tests. My strengths in this unit was being able to identify the functions of the different blood vessels and the different diseases (causes and effects). 

My health goals (from Unit 2 Reflection) were to eat more fruits and to sleep more. I have been eating more fruits; however, my amount of sleep has remained the same because of tennis and work from school. It is hard to balance out both my tennis practice and homework. For the remainder of the semester, I hope to spend more time understanding the pictures because they are very helpful in understanding the unit.

Pictures:

For the video above, we made one mistake toward the end of the video. After the left ventricle, we said it goes through bicuspid vale but it actually goes through the aortic semilunar valve into aorta and out to the body.
Picture one is a picture of the heart we drew on the street. Picture two is a picture of the heart during dissection. Picture three is a selfie we took with the heart at the beginning.