Anatomy and Function of the Cardiovascular System

The Central Role of the CV is to Distribute Oxygen to Cells

Left Ventricle Right Ventricle The Primary Organ of the CV System is the Heart, a Four-Chamber Pump That Provides the Driving Force for Blood Flow

The Flow of Blood From the Body to the Heart and Back Again

The Circulation Also Must Supply the Heart Muscle Itself

The Flow To and From the Heart Is Systematic

Atherosclerosis is Restricted Blood Flow Through the Coronary Arteries

Consequences of Disruption of Coronary Artery Flow Thrombosis Myocardial Infarction…. “Heart Attack”

Coronary Bypass Surgery-Method to Circumvent Arterial Blockage and Restore Coronary Circulation Arterial Graphs Pacemaker Leads

Spontaneous Electrical Activity in the Heart The electrical signals generated by the heart are what are referred to as an EKG or “electrocardiogram” Signal Begins here

“Normal” EKG is an indication that all the tissues are properly conducting electrical impulses There are a large number of departures from this normal- looking EKG that indicate tissue damage or dysfunction. Distorted QRS complex ST segment depression

PS vagus nerve Sympathetic accelerator nerve A-V Node S-A Node Heart Rate and Contractile Strength are Controlled by Input From Two Systems:Parasympathetic and Sympathetic Spinal Cord

Effects of the Parasympathetic and Sympathetic on Cardiovascular Function PS Vagus Heart Heart Rate Blood pumped from the Heart & Blood Pressure Sympathetic Heart Heart Rate Blood pumped from the Heart & Blood Pressure Arterioles Constriction Blood Pressure “Fight or Flight”

As vessels get further from the heart, they decrease in size but increase in importance.

Constriction Versus Capacitance Vessels The Ability to Constrict Arterioles is Vital for Distributing Blood to Various Tissues Critical because there is a limited supply of blood and competition exists between tissues

ARTERIOLES ARE THE PRIMARY “FLOW REGULATING” VESSELS Capillaries assist in this process by opening/closing in response to different metabolic conditions. This is also the site where fuel and gas exchange takes place

Capillaries Arterioles Capillaries are the smallest elements of the “plumbing system” Their density is a function of the need of the specific tissue for oxygen e.g. fast twitch versus slow twitch muscle

Transfer of fuel,O 2,CO 2 etc. to and from blood and cells is accomplished at the capillaries via a process called “diffusion” which requires a difference in concentration between the two compartments. Cell Capillary i.e. Concentration blood O2 > Concentration cell O2 = flow from blood to cell