Align-ju STUDENT
Arteries
Arteries are the largest blood vessels in the body . They carry oxygenated blood to the different vital organs . The only artery that carries deoxygenated blood is the pulmonary artery , which takes deoxygenated blood from the heart to the lungs . Arteries have thick walls that also include a layer of muscular-type tissue to help keep the blood moving ( Figure 2 ). Arteries can branch into smaller structures , known as arterioles .
Unlike veins , arteries do not contain valves , as the blood is kept moving by arterial pressure [ 2 ] . An animal ' s heartbeat can often be felt by palpating a superficial artery , such as the femoral artery .
The heart
The heart ( Figure 3 ) is the main organ involved in the function of the cardiovascular system . Without a correctly functioning heart , an animal can face severe consequences and even death .
The function of the heart is to pump blood around the body to the organs [ 3 ] . It is divided into four chambers :
Right ventricle
The blood from the right atrium passes through the tricuspid valve , also known as the right atrioventricular valve , into the right ventricle . When the ventricle is full , the heart contracts and forces the blood through a valve called the pulmonic valve and into the left and right pulmonary arteries . The pulmonary arteries carry the deoxygenated blood to the lungs to become oxygenated .
Left atrium
The left atrium receives blood that has returned from the lungs via the pulmonary vein . The left atrium fills with oxygenated blood and , when it is full , the heart contracts and passes the blood into the left ventricle .
Left ventricle
The left ventricle receives blood from the left atrium via the bicuspid valve , also known as the left atrioventricular or mitral valve . From the left ventricle , the blood leaves the heart via the aortic valve and enters the aorta ( an artery ). The oxygenated blood then joins the systemic circulation and travels around the body [ 1 ] .
Right atrium
The right atrium receives blood from the cranial vena cava , the main vein that delivers deoxygenated blood to the heart from the body . Once the atrium is full , the heart contracts and forces the blood out of the atrium .
Interventricular septum
The interventricular septum is a wall of cardiac tissue that separates the left and right ventricles of the heart . The septum mostly consists of cardiac muscle tissue , but it also contains a membranous layer [ 4 ] .
Aorta
Superior vena cava Pulmonary artery
Pulmonary vein
Pulmonary vein
Right atrium Left atrium
Pulmonic valve
Tricuspid valve
Inferior vena cava
Right ventricle Interventricular septum
Mitral valve
Aortic valve
Left ventricle
Figure 3 . Anatomy of a heart .
Volume 38 ( 4 ) • August 2023
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