Heart Dissection Internal Examination

Objectives 1.Complete an internal dissection of the heart. A.Label different parts of the heart B.Review the parts with a partner 2.Clean after the dissection

What do you need??? Red dots and Green dots… – Get APRONS and GOGGLES for everyone at your table Blue dots and Yellow dots… – Get a DISSECTION PAN – Get a HEART You have 5 minutes to get the materials.

First Thing… You need to remove the percardium from the heart. – Remember, the pericardium is a mucous membrane that surrounds the heart. Cut the top layer (pericardium) at the apex Peel the pericardium from the heart.

Second Thing… You need to trim the fat from the aorta, pulmonary vein, pulmonary artery, and superior vena cava. Do this carefully using the scalpel and scissors.

First Cut Locate the pulmonary artery Put the scissors inside of it. Cut through the front side of this vessel. Continue cutting down the artery and down through the muscular wall of the right ventricle. – This line should be above and parallel to the coronary artery. Stop cutting when you reach the end of the cavity of the right ventricle.

Now you can see… At the beginning of the pulmonary artery… – You can see the pulmonary semilunar valve Look inside of the right atrium – In the upper left of the right ventricle – Notice a flap of tissue made of 3 leaflets This is the tricuspid valve This is connected by a bunch of tendons called chordae tendinaea The thicker portion attaching the tendons to the wall are papillary muscles

Second Cut Find the superior vena cava… – Cut from the superior vena cava straight down about 3 centimeters – This will cut into the right atrium, but DO NOT cut into the right ventricle. Look through the right ventricle. – This is the tricuspid valve.

Third Cut Find the aorta… – Cut straight down through the aorta – Slowly cut until you can see the aortic semilunar valve

First Incision Locate the right atrium – Feel the right side (remember this is the side with the superior vena cava) – Find the chamber of the right atrium (heart will depress here) – Slide your finger until you cannot feel the chamber Move away from the middle of the heart – Cut just through the atrial wall DO NOT cut too far, just through the wall. – Continue the cut through the right ventricle and into the apex”

Second Incision Continue the first incision… – Start at the apex – Cut up the left side of the heart – Cut through the wall, but DO NOT cut past the wall

Identification Now you can identify… – Myocardium – Septum – Chordae Tendinaea – Papillary Muscle – 4 chambers: Right Atrium, Left Atrium, Right Ventricle, Left Ventricle – 4 valves: Aortic semilunar, Pulmonary semilunar, Mitral bicuspid, Tricuspid

Measurements Measure the thickness of the wall of the right ventricle in centimeters. – Write this measurement down on a sheet of paper Measure the thickness of the wall of the left ventricle in centimeters. – Write this measurement down on a sheet of paper

Blood Flow Can you track the blood through the heart?????? – Test your partner to see if she/he knows the blood flow pattern.

Clean-up Clean the scalpel, scissors, and any other tools used in the soapy water. Dry the tools Place the tools back where they should be. You will lose half of the lab points if this is not done.