Dissection of a Pig’s Heart

External Structures: Locate these structures and use the tags to identify each Left atrium – upper chamber to your right Left ventricle- lower chamber to your right Right atrium- upper chamber to your left Right ventricle- lower chamber to your left

Internal Structures: Locate these major blood vessels; use the tags to identify each Insert a glass rod into each of the following blood vessels: Coronary artery Pulmonary artery Aorta Pulmonary veins Inferior & Superior Vena Cava

Procedure - Internal Anatomy  Opening the right ventricle: Find the pulmonary artery and insert a glass rod so that the rod extends into the right ventricle Use scissors to cut through the side of the pulmonary artery and continue cutting down into the wall of the right ventricle.

First cut: Examine the right ventricle: Push open the heart at the cut to examine the internal structure.

The valves inside the pulmonary artery: Inside the right ventricle, locate the pulmonary artery that carries blood away from this chamber. Find the one-way valve called the pulmonary valve that controls blood flow away from the right ventricle at the entrance to the pulmonary artery.

The right atrium: Locate the right atrium. Notice the thinner muscular wall of this receiving chamber.

Superior and inferior vena cava: In the right atrium: Find where the inferior & superior vena cava enter this chamber notice the lack of valves.

The atrioventricular valve: Locate the valve between the right atrium and right ventricle. This is the atrioventricular valve (aka tricuspid valve) The valve consists of three leaflets & has long fibers of connective tissue called chordae tendinae that attach it to papillary muscles of the heart

The right ventricle: Use your fingers to feel the thickness of the right ventricle and its smooth lining. Also note the network of muscular cords on the inner wall of this chamber.

The left ventricle: Using scissors, make a cut in the left atrium: Insert a glass rod in the left atrium opening and feed it downward into the left ventricle, all the way to the apex. Cut with scissors all the way down the glass rod, staying on the left of septum.

The left ventricle: Push open the heart at this cut with your fingers.

Find the valve between the left atrium an the left ventricle: Inside the left ventricle: Look for the valve that controls blood flow between the left atrium and the left ventricle. This is called the auriculoventricular valve (aka mitral or bicuspid valve)

Thickness of left ventricle wall: Examine the left ventricle: Notice the thickness of the ventricular wall. This heart chamber is responsible for pumping blood throughout the body.

Expose the aortic valve: Using your scissors: Cut across the left ventricle toward the aorta Continue cutting to expose the valve. 

Find the Aortic Valve: Leading from the left ventricle into the aorta: Count the three flaps or leaflets on this valve note their half-moon shape. This is the aortic valve.

Find the Aortic Sinus: Using scissors, open the aorta: Find the small opening or coronary sinus in the wall of the aorta, just above the aortic valve. The sinus leads to the coronary artery which carries blood to the heart muscle itself.

AORTIC SINUS

The coronary sinus in the wall of the aorta: