Cardiovascular System A closed system of the heart and blood vessels Objectives: Describe the location of the heart in the body and identify the heart chambers, sounds, and valves. Trace the pathway of blood through the heart and compare the functions of the heart chambers on the right and left sides. Compare the pulmonary and systemic circuits.

The Cardiovascular System The function of the cardiovascular system TRANSPORTATION deliver oxygen deliver nutrients movement of hormones remove carbon dioxide remove urea remove other waste products

Blood: the mechanism for transport of these materials Blood vessels: tubes through which materials are transported Heart: the force that keeps materials circulating

The Heart Location Thorax between the lungs in the inferior mediastinum Orientation Pointed apex (tip) directed toward left hip Base (where the blood vessels emerge) points toward right shoulder About the size of your fist Hollow Cone shaped

The Heart: Coverings Pericardium—a double-walled sac 1. Fibrous pericardium is loose and superficial for protection to hold the heart in place

The Heart: Coverings Serous pericardium (deep to the fibrous pericardium) 2 layers a. Visceral pericardium Next to heart; also known as the epicardium b. Parietal pericardium Outside layer that lines the inner surface of the fibrous pericardium Serous fluid fills the space between the layers of pericardium

1. Heart 2. Fibrous pericardium 3. Parietal layer of serous pericardium 4. Visceral layer of serous pericardium 5. Pericardial space 6. Pleural cavity and lung

The Heart: Heart Wall 3 layers Epicardium (AKA: visceral pericardium) Outside layer Connective tissue layer Myocardium Middle layer Mostly muscle Endocardium Inner layer Endothelium

The Heart: Chambers Right and left side act as separate pumps Four chambers Atria (plural) Receiving chambers Right atrium Left atrium Ventricles Discharging chambers Right ventricle Left ventricle

Differences in Right and Left Ventricles Left ventricle is visibly more muscular It is responsible for pushing the blood out of the heart and into the vessel systems that carry blood to the entire body Figure 11.4

The Heart: Septa Tissue dividing the chambers Named based on their location Interventricular septum Separates the two ventricles Interatrial septum Separates the two atria

The Heart: Valves Allow blood to flow in only one direction to prevent backflow 4 valves Atrioventricular (AV) valves between atria and ventricles 1. Bicuspid (AKA: mitral) valve (left side of heart) 2. Tricuspid valve (right side of heart)

The Heart: Valves Semilunar valves between ventricle and artery 3. Pulmonary semilunar valve 4. Aortic semilunar valve

The Heart: Valves AV valves (Tricuspid/Bicuspid) Anchored in place by chordae tendineae (“heart strings”) which attach to papillary muscle to keep them from turning inside out Open during heart relaxation and closed during ventricular contraction

The Heart: Valves Semilunar valves Closed during heart relaxation but open during ventricular contraction Notice these valves operate opposite of one another to force a one-way path of blood through the heart

2 Main Types of Circulation 1. Systemic circulation Blood flows from the left side of the heart through the body tissues and back to the right side of the heart

2 Main Types of Circulation 2. Pulmonary circulation Blood flows from the right side of the heart to the lungs and back to the left side of the heart

Systemic and Pulmonary Circulations Figure 11.3

The Heart: Associated Great Vessels Arteries Aorta Leaves left ventricle Pulmonary arteries Leave right ventricle

The Heart: Associated Great Vessels Veins Superior and inferior venae cavae Enter right atrium Pulmonary veins (four) Enter left atrium

The Heart: Summary http://www.mayoclinic.com/health/circulatory-system/MM00636 Figure 11.2c

The Heart: Associated Great Vessels Figure 11.2c

Blood Flow Through the Heart Superior and inferior venae cavae dump blood into the right atrium From right atrium, through the tricuspid valve, blood travels to the right ventricle From the right ventricle, blood leaves the heart as it passes through the pulmonary semilunar valve into the pulmonary trunk Pulmonary trunk splits into right and left pulmonary arteries that carry blood to the lungs

Blood Flow Through the Heart Oxygen is picked up and carbon dioxide is dropped off by blood in the lungs Oxygen-rich blood returns to the heart through the four pulmonary veins Blood enters the left atrium and travels through the bicuspid valve into the left ventricle From the left ventricle, blood leaves the heart via the aortic semilunar valve and aorta

Practice!! http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter22/labeling_exercises.html Practice Labeling