At the end of this unit you should be able to:•Relate the structures of the cardiovascular system to the primary functions.•Identify external and internal structures of the heartincluding the layers, chambers and valves.•Trace the flow of blood through the pulmonary and systemic pathways of the heart and great vessels.•Identify the parts of the heart supplied by the major coronary arteries and drained by the major coronary veins. Identify the vessels and their course.•Characteristics of cardiac muscle tissue•Compare and contrast the various components of the heart's conduction system.Including external control and feedback to the heart•Describe the electrical and mechanical events of the cardiac muscle cells compared to skeletal muscle cells. •Given an EKG tracing, identify the electrical events including the intervals and segments.•Outline the events of the cardiac cycle.•Apply the functioning of the conduction system to the mechanical events of the cardiac cycle.•Relate factors that influence cardiac output, stroke volume, heart rate, and reserve.
Components of the Cardiovascular System•The Blood Vessels–Arteries–Veins–Capillaries•The Blood•The Heart*APR: Cardiovascular System Overview
Function of the Cardiovascular SystemDelivers oxygen and nutrients and removes waste and carbon dioxide throughout the body. Provides adequate perfusionof tissues.
The Heart: LocationThe heart is located in the mediastinumAbout 2/3 of the heart lies to the left of the body’s midline
The Heart: Size & ShapeThe heart is approximately the size of a closed fist and is shaped like a cone laying on its side.BaseApex
Layers of the Heart•The heart is composed of several layers. From superficial to deep they are: •The pericardium•The epicardium •The myocardium•The endocardium
•Fibrous pericardium – helps retain the hearts position in the mediastinum and prevents overfilling of heart–Dense irregular connective tissue•Serous pericardium –reduces friction for heart movement–Parietal layer–Visceral layer (same as epicardium)–Pericardial fluid in potential spaceThe Pericardium
The EpicardiumEpithelial and connective tissue layer covering the heartSame as visceral layer of pericardiumThis is the outermost layer of the heart wall.
The MyocardiumCardiac MuscleThis is the middlelayer of the heart wall which is composed of cardiac muscle. Thickest of the three layers. Thickness varies according to function of each chamber
The EndocardiumThis is the innermost layer of the heart wall and is continuous with the inner lining of the blood vessels.Epithelial tissue with basement membrane
Anatomy of the Heart: The ChambersLeft AtriumLeft VentricleRight AtriumRight VentricleThe heart is comprised of 4chambers.
Chambers of the Heart•Chamber separation–Interatrial septum•thin wall separating right and left atria–Interventricular septum•thick wall separating right and left ventriclesInteratrial SeptumInterventricular Septum