Sheep’s Brain Dissection Lab Report:
Introduction:
The purpose of this dissection was to elaborate on what we learned about the heart. And also to get a visual explanation of the different chambers, valves, ventricles, and atriums.
Methods:
EXTERNAL OBSERVATION PROCEDURES:
· First we had identify the right and left sides of the heart. Look closely and on one side you will see a diagonal line of blood vessels that divide the heart. The half that includes all of the apex (pointed end) of the heart is the left side.
· Then we had to confirm this by squeezing each half of the heart. The left half will feel much firmer and more muscular than the right side. (The left side of the heart is stronger because it has to pump blood to the whole body. The right side only pumps to the lungs.)
· Then we had to locate the coronary arteries and veins that are on the surface of the heart.
· Then we had to find the flaps of the dark tissue on the top of the heart. These ear-like flaps are called auricles. This was kind of difficult.
· Then, a little down and to the left of the superior vena cava there is another blood vessel opening. Insert your probe into this; it should also lead into the right atrium. This is the inferior vena cava, which brings blood from the lower tissues.
· Then we saw another blood vessel next to the left auricle. Which is the pulmonary vein that brings blood from the lungs to the left atrium.
· Then we saw the aorta sticking straight up from the center of the heart, it which oxygenated blood from the left ventricle to the rest of the body (the ventricles are the lower chambers of the heart).
· Then behind that, we found the pulmonary artery which takes blood from the right ventricle to the lungs.
Internal Observation (Dissection)
· Insert your dissecting scissors or scalpel into the superior vena cava and make an incision down through the wall of the right atrium and ventricle. Pull the two sides apart and look for three flaps of membrane. These membranes form the tricuspid valve between the right atrium and the right ventricle.
· The valves are connected to the papillary muscles by tendons called the chordae tendinae or "heart strings" LOCATE THESE STRUTURES.
· Insert your probe into the pulmonary artery and see it come through to the right ventricle. Make an incision down through this artery and look inside it for three small membranous pockets. These form the pulmonary semilunar valve which prevents blood from flowing back into the right ventricle.
· Make an incision down through the wall of the left atrium and ventricle. LOCATE THE MITRAL VALVE (OR BICUSPID VALVE) between the chordae tendinae on this side of the heart.
· Insert a probe into the aorta and observe where it connects to the left ventricle. Make an incision up through the aorta and examine the inside carefully for three small membranous pockets. These form the aortic semilunar valve.
Discussion:
The only difficulty me and Alize had was figuring out where to place the probes, and then when we did figure it out, we couldn’t figure out where the probe that was inserted into the Aorta was supposed to exit. Alize and I watched a few additional videos on the heart, to further understand the blood flow and to learn about heart attacks and what actually goes on inside the heart during one. One question we had is “If you severe the Carotid Artery, which ventricle or artery empties first?”
Differences between the human heart and sheep’s heart are: body position, since sheep's corporal position is horizontal, pumping from the left ventricle needs to be stronger because most of the blood will be pumped at almost the same high (in humans most of the blood goes downwards). This makes the left ventricle to be thicker. Also for the same reason, the vessels entering the heart (aorta, vena cava) had different entry angles.
Introduction:
The purpose of this dissection was to elaborate on what we learned about the heart. And also to get a visual explanation of the different chambers, valves, ventricles, and atriums.
Methods:
EXTERNAL OBSERVATION PROCEDURES:
· First we had identify the right and left sides of the heart. Look closely and on one side you will see a diagonal line of blood vessels that divide the heart. The half that includes all of the apex (pointed end) of the heart is the left side.
· Then we had to confirm this by squeezing each half of the heart. The left half will feel much firmer and more muscular than the right side. (The left side of the heart is stronger because it has to pump blood to the whole body. The right side only pumps to the lungs.)
· Then we had to locate the coronary arteries and veins that are on the surface of the heart.
· Then we had to find the flaps of the dark tissue on the top of the heart. These ear-like flaps are called auricles. This was kind of difficult.
· Then, a little down and to the left of the superior vena cava there is another blood vessel opening. Insert your probe into this; it should also lead into the right atrium. This is the inferior vena cava, which brings blood from the lower tissues.
· Then we saw another blood vessel next to the left auricle. Which is the pulmonary vein that brings blood from the lungs to the left atrium.
· Then we saw the aorta sticking straight up from the center of the heart, it which oxygenated blood from the left ventricle to the rest of the body (the ventricles are the lower chambers of the heart).
· Then behind that, we found the pulmonary artery which takes blood from the right ventricle to the lungs.
Internal Observation (Dissection)
· Insert your dissecting scissors or scalpel into the superior vena cava and make an incision down through the wall of the right atrium and ventricle. Pull the two sides apart and look for three flaps of membrane. These membranes form the tricuspid valve between the right atrium and the right ventricle.
· The valves are connected to the papillary muscles by tendons called the chordae tendinae or "heart strings" LOCATE THESE STRUTURES.
· Insert your probe into the pulmonary artery and see it come through to the right ventricle. Make an incision down through this artery and look inside it for three small membranous pockets. These form the pulmonary semilunar valve which prevents blood from flowing back into the right ventricle.
· Make an incision down through the wall of the left atrium and ventricle. LOCATE THE MITRAL VALVE (OR BICUSPID VALVE) between the chordae tendinae on this side of the heart.
· Insert a probe into the aorta and observe where it connects to the left ventricle. Make an incision up through the aorta and examine the inside carefully for three small membranous pockets. These form the aortic semilunar valve.
Discussion:
The only difficulty me and Alize had was figuring out where to place the probes, and then when we did figure it out, we couldn’t figure out where the probe that was inserted into the Aorta was supposed to exit. Alize and I watched a few additional videos on the heart, to further understand the blood flow and to learn about heart attacks and what actually goes on inside the heart during one. One question we had is “If you severe the Carotid Artery, which ventricle or artery empties first?”
Differences between the human heart and sheep’s heart are: body position, since sheep's corporal position is horizontal, pumping from the left ventricle needs to be stronger because most of the blood will be pumped at almost the same high (in humans most of the blood goes downwards). This makes the left ventricle to be thicker. Also for the same reason, the vessels entering the heart (aorta, vena cava) had different entry angles.