Unit 3 Reflection

Unit 3 - The Circulatory System
Unit Summary

Medical treatments of heart disease include beta-blockers, aspirin, anti-coagulants, nitroglycerin, calcium channel blockers, anti-hypertensives, TPA (Tissue Plasminogen Activator), and anti-lipids or statins which are the current biggest sellers. A stroke a is heart attack in the brain. A stroke occurs when there is a shortage of blood supply to the brain. Ischemic strokes are the most common and where an artery supplying the brain is blocked. Hemorrhagic strokes are less common, but more deadly where an artery supplying the brain bursts. A transient ischemic attack (TIA) is a minor less threatening stroke that lasts a few minutes and is normally a warning sign for future more deadly strokes. Signs of strokes are impairment in vision, movement, speech, and comprehension. CT's and MRI's are both methods used for diagnosis of a stroke. Treatments for strokes are TPA and MERCI. The most effective way to not have a stroke is prevention which is keeping a low blood pressure, eating healthy with less cholesterol, exercising, and managing stress.

sheep heart dissection

Sheep Heart Dissection

1) What is the purpose of the pericardium?
The purpose of the pericardium is to act as protection for the heart from physical damage and infections. The pericardium also holds the heart in place.

2) Observe the blood vessels connecting to the heart. How do the arteries differ from veins in their structure?
Arteries and veins differ in that arteries carry blood from the heart to the body or lungs, and the veins carry blood from the lungs and body to the heart. Arteries also have thinner walls to carry more blood.

3) Place your finger inside the auricle. What function do you think the auricle serves?
The purpose of the auricle is to help increase the capacity of blood that can go into the atrium.

4) Observe the external structures of the atria and ventricles. What differences do you observe?
On the external structure of the heart, the atria seem to be larger and able to hold more blood than the ventricles. The atria are on the thicker side of the heart while the ventricles are on the narrower side of the heart.

5) Use pictures or words to describe each.
a) exit from the coronary sinus
The coronary sinus is a small hidden channel on the right side of the heart. It recieves blood from the coronary veins and delivers it to the coronary arteries.
b) inferior vena cava
The inferior vena cava is at the bottom of the heart. The inferior vena cava is a vessel where blood enters the heart coming from the body.
c) right atrioventricular valve (tricuspid valve)
The right atrioventricular valve, also known as the tricuspid valve, connects the right atrium to the right ventricle.

6) Draw a picture of the tricuspid valve, including chordae tendinae and the papillary muscle.

7) Why is "anchoring" of the heart valves by the chordae tendinae and the papillary muscle important to heart function?
The "anchoring" by the chordae tendinae and the papillary muscle are very important to the heart function, because it holds onto the valve. Holding onto the valve prevents backflow of the blood with is extremely important in keeping the heart healthy.

8) Using pictures or words, describe what you see.
Under the glove, there is are tube-looking indents which are the bicuspid valve. The chordae tendinae is beneath the bicuspid valve deeper into the heart. The papillary muscle is just under the chordae tendinae.

9) What is the function of the semilunar valves?
The function of the semilunar valves is to make sure blood doesn't flow back into the heart after the blood has entered either the aorta or pulmonary trunk.

10) Valvular heart disease is when one or 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.
a) 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?
A valve disease in the right side of the heart might cause swelling in the feet and ankles because the feet and ankles are the furthest from the heart, so when the valves are weak, there might not be enough strength to push the same amount of blood all the way to the feet and ankles.
b) if the valve disease occurs on the left side of the heart, what complications would you expect to see?
If the valve disease occurred the on the left side of the heart, I would expect to see swelling and pain in the lungs and chest.

11) Using picture and/or words describe what you see.
The right side of the heart holds the tricuspid valve which connects blood from the right atrium and the right ventricle. The cordae tendinae is right under the valves which keep the valve restricted so blood doesn't flow backwards. The left side has the bicuspid valve with 3 cusps and the papillary muscle to keep the blood from backflowing. The coronary arteries are along the outside layer of the heart, providing blood to the heart.

12) Describe how the left and ride sides of the heart differ from each other.
The left side and right side of the heart differ in the sense that the right atrium and ventricle deliver blood from the heart to the lungs. The left side of the heart delivers blood from the heart to the rest of the body. The right side of the heart has a larger myocardium because it requires more strength to deliver more blood since the whole body needs a lot more blood than just the lungs.

13) Draw and label all structure visible in the interior of the cross-section.