Home | Index | Next                               CARDIOVASCULAR SYSTEM

 

INTRODUCTION                           

Optimal patient care requires that the EMT - I understand the anatomy and physiology of the cardiovascular system.  The following topics will be discussed during this lesson:

 

 

·                      Components of the cardiovascular system

 

·                      Unique properties of the heart

 

·                      Factors affecting cardiac output

 

·                      Path of blood flow through the body

 

·                      Importance of peripheral vascular resistance

 

·                      Components of blood

 

LESSON OBJECTIVES

At the end of this lesson the participants will be able to:

 

 1.        Name the three components of the cardiovascular system

 

 2.        Name the four tissue layers of the heart.

 

 3.        Describe the functions of the left and right side of the heart.

 

 4.        Understand the function of the coronary arteries and heart valves.

 

 5.        List five unique properties of the heart.

 

 6.        Understand how heart rate, right heart return, and chamber filling effect cardiac output.

 

 7.        Trace the path of blood flow through the heart and through the body.

 

 8.        Describe the structure and function of arteries, capillaries, and veins.

 

 9.        Describe the relationship between the three factors that affect blood pressure.

 

10.              Discuss the significance of five parameters used to determine perfusion

 

11.       Name the four components of blood and list the function of each.

 

SKILLS

None

 

KEY VOCABULARY 

The following terms will be used during this lesson:

 

·          Perfusion - blood flow into or through an organ

 

·          Systole - period during which the myocardium contracts

 

·          Diastole - period during which the myocardium relaxes

 

·          Myocardium - thick, muscular layer of the heart

 

·          Stroke Volume - amount of blood ejected from the ventricle during one systole

 

·          Cardiac Output - amount of blood pumped by the heart in one minute, depends on stroke volume and heart rate

 

KEY CONCEPTS  

The following section provides information and space for taking notes on the key concepts discussed by the instructor:

 

Components of the Cardiovascular System 

·        Heart

·        Blood vessels

·          arteries

·          capillaries

·          veins

·        Blood

 

HEART

Definition:

•     A double pump which delivers oxygen throughout the body

 

 Tissue Layers of the Heart

•     Pericardium:

 

•     Epicardium:

 

·          Myocardium:

 

·          Endocardium

a protective sac that surrounds the heart

 

the outermost lining of the heart

 

the thick, muscular middle layer of the heart

 

smooth inner lining of the heart

 Right Heart

·          Right Atrium:

 

·          Right Ventricle:

receives deoxygenated blood from the vena cava.

 

low pressure system that pumps blood to the pulmonary  circulation (lungs)

 

 Left Heart:

·          Left Atrium:

 

 

·          Right Ventricle:

 

receives oxygenated blood from the pulmonary circulation

 

high pressure system that pumps blood to the aorta and the rest of the body

 

 

 Coronary Arteries

•     The first branch off of the aorta

 

•     Supply oxygen and nutrients to the myocardium

 

 Heart Valves

Function:

·          prevent back flow of blood in the heart

 

 

Location:

Atrioventricular Valves:

 

•    Separate atria from ventricles

 

•    Tricuspid -  right side

 

•    Mitral (Bicuspid) - left side

  Semi-Lunar Valves

 

•    Separate ventricles from arteries

 

•    Pulmonic - right side

 

·          Aortic - left side

 

 

 

  Unique Properties of the Heart

•    Automaticity

 

•    Irritability

 

•    Conductivity

 

•    Contractility

 

•    Rhythmicity

 

 

GOLDEN RULE: Mechanical action of the heart can only be

                                 assessed by pulse quality and blood pressure

 

 

Factors Affecting Cardiac Output:

•    Heart Rate

 

•    Right Heart return

 

•    Chamber filling

 

CO  =  SV x HR

 

 

Path of Blood Flow

•     Superior & inferior vena cava

•     Right atrium

•     Through the tricuspid valve

•     Right ventricle

•     Through the pulmonic valve

•     Pulmonary artery and pulmonary circulation

•     Left atrium

•     Through the mitral valve

•     Left ventricle

•     Through the aortic valve

•     Aorta

•     Arteries

•     Arterioles

•     Capillaries

•     Venules

•     Veins

 

BLOOD VESSELS

•     Arteries

 

•     Capillaries

 

•     Veins

 

 

Structure and Function of Arteries

•     High pressure side of system

 

•     Carry blood away from heart

 

•     Thick, muscular walls

 

 

Structure and Function of the Capillaries

•     Semi-permeable membrane

 

•     One cell thick

 

•     Site of gas exchange

 

 

Structure and Function of Veins

•     Low pressure side of system

 

•     Carry blood toward heart

 

•     Capable of massive dilation

 

 

 Maintenance of Blood Pressure:

•     Adequate blood volume

 

•     Adequate cardiac output

 

•     Adequate Peripheral Vascular Resistance

 

                        BP = CO x PVR

 

 

 

 

Factors Used to Determine Perfusion

•     Skin signs

 

•     Pulse quality

 

•     Capillary refill

 

•     Blood pressure

 

•     Level of consciousness

 

BLOOD

Blood Components

•     Red blood cells

 

•     White blood cells

 

•     Platelets

 

•     Plasma

  Home | Index | Next