Cardiovascular System

Function - Func&ons to carry oxygen and nutrients to the cells of the body and carry carbon dioxide and other waste away from the cells of the body.

Structures - Heart - pumps blood to the lungs and throughout the body - Arteries, arterioles - Caries blood AWAY from the heart to cells - Capillaries - Place where nutrient and gas waste exchanges - Veins, venules - Carries blood TO the heart from cells

Arteries vs. Veins - Arteries - THICK! - Veins - Thinner

Pulmonary vs. Systemic Circuits - Pulmonary - Carries Oxygen depleted blood to the lungs to pick up O 2 and unload CO 2. - Systemic - Sends oxygen- rich blood from heart to all body cells.

The Heart - Located in the thoracic cavity, rests on top of the diaphragm - Encased in a parietal pericardium

Wall of the Heart 1. Outer Epicardium Made of epithelial &ssue Protects the heart by reducing fric&on 2. Middle Myocardium Mostly cardiac &ssue involved in pumping blood out of the heart 3. Inner Endocardium Made of epithelial &ssue Lines the inner chambers of the heart

- Atria - Upper chambers - Receive blood returning to the heart - Ventricles - Lower chambers - Receive blood from atria and force blood into arteries - Septum - Separates leq and right so blood doesn t mix Heart Chambers

Heart Valves - Atrioventricular Valves: separate atria from ventricles and prevent back- flow of blood. - Tricuspid: - Right side - Bicuspid/Mitral: - LeQ side

Heart Valves - Semilunar Valves: - Pulmonary: - Found between the right ventricle and the pulmonary artery - Aor+c: - Found between the leq ventricle and the aor&c arch

Blood Flow

Cardiac Cycle - Systole= contrac&on - Diastole = relaxing * During atrial systole, ventricles are in ventricular diastole * During ventricular systole, atria are in atrial diastole Both relax briefly aqer ventricular systole Cycle Anima&on

Steps of the Cycle 1) Pressure is low during ventricular diastole, opening the A- V valves (tricuspid/bicuspid)

Steps of the Cycle 1) Pressure is low during ventricular diastole, opening the A- V valves (tricuspid/bicuspid) 2) Ventricles fill with blood

Steps of the Cycle 1) Pressure is low during ventricular diastole, opening the A- V valves (tricuspid/bicuspid) 2) Ventricles fill with blood 3) A- V valves close when ventricular pressure exceeds atrial pressure

Steps of the Cycle 5) Ventricular pressure rises, opening the semilunar valves, forcing blood into the pulmonary trunk and aor&c arch

Steps of the Cycle 5) Ventricular pressure rises, opening the semilunar valves, forcing blood into the pulmonary trunk and aor&c arch 6) Pressure drops in ventricles aqer contrac&on, and the semilunar valves close. Echocardiogram

Heart Sounds - The heart makes a Lubb- Dubb sound - The Lubb is the closing of the A- V valve during ventricular contrac&on. - The Dubb is the closing of the semilunar valve when the ventricles are relaxing.

Cardiac Conduction System - Coordinates the events of the cardiac cycle

Cardiac Conduction System 1) The Synotrial Node (SA Node)- Pacemaker - Specialized cardiac muscle &ssue - Can reach threshold on its own - Generates impulses 70-80 &mes per minute

Cardiac Conduction System 1) The Synotrial Node (SA Node)- Pacemaker - Specialized cardiac muscle &ssue - Can reach threshold on its own - Generates impulses 70-80 &mes per minute 2) Atrial sync&um causes atrial contrac&on

Cardiac Conduction System 1) The Synotrial Node (SA Node)- Pacemaker - - - Specialized cardiac muscle &ssue Can reach threshold on its own Generates impulses 70-80 &mes per minute 2) Atrial sync&um causes atrial contrac&on 3) A- V Node relay sta&on (slows current) 4) A- V Bundle sends signals from A to V 5) Purkinje Fibers causes ventricular contrac&on

Conduc&on Cardiac Conduction

Electrocardiogram Recording of the electrical changes that occur in the myocardium (cardiac muscle)

Electrocardiogram P- wave: depolariza&on of atria QRS: depolariza&on of ventricle fibers (R=LeQ, S=right) T- wave: repolariza&on of ventricles

Blood Pressure (13.5) Blood pressure= the force blood exerts against the inner walls of blood vessels.

Measuring Blood Pressure Systolic Pressure: max pressure during ventricular systole Diastolic Pressure: max pressure during ventricular diastole