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Heart

Heart

Description:

This lesson will identify the major structures of the heart and define their specific role in the overall functioning of the heart.

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Tutorial

What's Covered

This lesson will cover the role the heart plays in the circulatory system by looking at

  1. The Structure of the Heart
  2. The Function of the Heart

1. The Structure of the Heart

The heart is primarily made of myocardium, and is a muscular pump whose job is to pump blood throughout the body. It is a very complex organ made up of various different parts.

Term to Know

    • Myocardium
    • The muscular tissue that composes the heart.

Our heart is broken up into two different halves, right and left and is composed of four chambers. The top chambers are the atria (singular is atrium), and the bottom chamber are the ventricles. Blood flows into our atria, and then down into our ventricles, and from there it will be pumped into either our body or lungs. The septum separates the two halves of the heart and the pericardium is the outer portion. The pericardium basically is a fluid filled sac that surrounds the heart whose its job is to protect and to lubricate the heart.

Terms to Know

    • Atrium
    • The right and left upper chambers of the heart.
    • Pericardium
    • A fluid filled sac that surrounds the heart and provides protection and lubrication.
    • Septum
    • A wall of tissue that separates the right and left halves of the heart.
    • Ventricle
    • The right and left lower chambers of the heart.

Some important blood vessels that connect to the heart are:

  • The aorta- an artery that delivers blood to the body. It's part; it delivers blood to the systemic circuit.
  • The superior vena cava- a vein whose job is to deliver oxygen lacking blood from the upper portion of our body into the right atrium.
  • The inferior vena cava- delivers oxygen-lacking blood from the bottom portion of our body into the right atrium.

Terms to Know

  • Aorta
  • An artery that delivers blood to the systemic circuit.
  • Superior Vena Cava
  • A vein that delivers deoxygenated blood from the upper portion of the body to the right atrium.
  • Inferior Vena Cava
  • A vein that delivers deoxygenated blood from the lower portion of the body to the right atrium.

Another important structure of the heart are valves:

  • The pulmonary valve is part of the right ventricle. Our pulmonary valve allows blood to flow from our right ventricle to our pulmonary artery.
  • The aortic valve allows blood to flow from the left ventricle to the aorta.
  • There are two atrioventricular valves, both right and left, or AVs for short. AV valves allow blood to flow from the atrium to the ventricles. When blood flows into the atrium, the AV valve will then open, allowing that blood to flow down into the ventricle; also preventing backflow.

Terms to Know

    • Atrioventricular Valve
    • A valve that allows blood to flow from the atrium to the ventricle while preventing backflow of blood.
    • Pulmonary Valve
    • A valve that allows blood to flow from the right ventricle to the pulmonary artery while preventing backflow.
    • Aortic Valve
    • A valve that allows blood to flow from the left ventricle to the aorta while preventing backflow.

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2. Function of the Heart

When blood flows into our heart, it will enter into the right atrium. This blood is lacking oxygen because it has been used by the body. It will go through the AV valve into the right ventricle, and then up through the pulmonary valve. Blood will be sent from here to your lungs to collect oxygen. It will then collect oxygen and enter into the left atrium. It will go down into the left ventricle through the AV valve, up through the aortic valve, and then is pumped throughout your body. Your body will use the oxygen in your blood, and the process will repeat.

Summary

The structure of the heart includes 4 chamber. The top two chambers are the atria, and the bottom two are ventricles. The are identified by being on either the right or left side of the heart. The septum is the structure that divides the right side from the left. The pericardium is the fluid-filled sack that surrounds the heart. Large arteries take oxygen rich blood from the heart to the rest of the body, and large veins return oxygen-lacking blood to the heart to be delivered to the lungs. The heart has many important valves to allow blood to flow from one area to another, without allowing for back flow. The function of the heart is to be the pump that circulates oxygen rich blood from the lungs to the rest of the body, and bring back oxygen depleted blood back through the heart, and into the lungs.

Keep up the learning, and have a great day!

Source: SOURCE: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND

TERMS TO KNOW
  • Myocardium

    The muscular tissue that composes the heart.

  • Atrium

    The right and left upper chambers of the heart.

  • Ventricle

    The right and left lower chambers of the heart.

  • Atrioventricular Valve

    A valve that allows blood to flow from the atrium to the ventricle while preventing backflow of blood.

  • Pulmonary Valve

    A valve that allows blood to flow from the right ventricle to the pulmonary artery while preventing backflow.

  • Aortic Valve

    A valve that allows blood to flow from the left ventricle to the aorta while preventing backflow.

  • Aorta

    An artery that delivers blood to the systemic circuit.

  • Septum

    A wall of tissue that separates the right and left halves of the heart.

  • Superior Vena Cava

    A vein that delivers deoxygenated blood from the upper portion of the body to the right atrium.

  • Inferior Vena Cava

    A vein that delivers deoxygenated blood from the lower portion of the body to the right atrium.

  • Pericardium

    A fluid filled sac that surrounds the heart and provides protection and lubrication.