Circulatory System

Circulatory System

• Your pigs have been doubly injected (red for arteries, blue for veins)

• Red arteries = move blood (rich in oxygen)

“Away” from the heart

• Blue veins = move blood (low in oxygen)

back to the heart

*sometimes there’s exceptions to this rule!!!!

Pericardium• Pericardium- a membrane (mesentery) surrounding

the heart. Secretes a watery fluid to prevent the heart from rubbing against surrounding organs when it beats.

• In living animals, the pericardial cavity is filled with fluid that acts as a shock absorber to protect the heart from injury

Coronary artery and Coronary vein

• The coronary artery and coronary vein lie in the diagonal groove between the 2 ventricles. 

• These vessels supply and drain the heart (the heart is a muscle and as such has the same requirements of any other organ). 

• When the coronary artery becomes obstructed, a heart attack may occur.  It is the coronary arteries that are "bypassed" in coronary bypass surgery. 

• Coronary Vein- blue blood vessel located on the front (ventral) surface of the heart. (May not be injected in all pigs.) Drains the heart muscle tissue of blood and moves it back into the right atrium.

• Coronary Artery- red blood vessel located on the front (ventral) surface of the heart. (May not be injected in all pigs) Brings blood from the aorta and supplies the heart muscle tissue with food and oxygen.

How blood flows

• In an adult mammal deoxygenated blood (low in O2)flows into the right atrium from the anterior and posterior vena cava. 

• It then makes the following circuit:  right ventricle, pulmonary trunk, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aortic arch, aorta, and on into the systemic circulation.

Blood pathway

How blood flows• Right Atrium- Collects blood low in oxygen

and filled with food from the body and pumps it into the right ventricle.

• Right Ventricle- Collects blood from the right atrium and pumps it to the lungs.

• Pulmonary Trunk- takes blood from the right ventricle to the lungs.

• Pulmonary Vein- returns oxygenated blood from lungs to the left atrium

• Left Atrium- Collects blood from the lungs rich in oxygen and food and pumps it to the left ventricle.

• Left Ventricle- Collects blood from the left atrium and pumps it throughout the body.

Aorta and Vena Cava • Aortic Arch- behind the pulmonary trunk and

forming an arch leading toward the lower part of the body. Carries blood rich in food and oxygen from the left ventricle to all parts of the body.

• Dorsal Aorta- continuation of the aorta along the dorsal body wall behind the lungs, liver, and small intestine. Carries blood rich in food and oxygen to the lower body organs and to the legs.

• Posterior Vena Cava- Brings blood through the umbilical cord low in oxygen and rich in carbon dioxide form the lower body to the right atrium.

Flow of blood through the heart

Model of human heart