Cardiovascular: Heart

GENERAL FUNCTIONS A. The primary function is circulation. B. Critical transportation needs

LAYERS OF THE HEART Epicardium -- outermost layer—visceral layer of serous membrane Myocardium-- middle, muscular wall of the heart-- Endocardium--inner layer. Contains epithelial tissue and is smooth.

Pathway of Blood Through the Heart

Pathway of Blood Through the Heart

Chambers of the Heart Receiving chambers: Atria Pumping chambers: Ventricles

Valves of the Heart Atrioventricular: tricuspid, bicuspid Semilunar: pulmonary, aortic

Papillary muscles and Chordae tendonae Papillary Muscles: anchor tendons Chordae tendonae: anchor flaps of valves Prevent back flow of blood

Locate apex of heart

Conduction system of the Heart SA--sinoatrial node: pacemaker AV--atrioventricular node: secondary pacemaker Bundle of His: conduction fibers R and L bundle branches Purkinje fibers: through both ventricles

ELECTROCARIOGRAM

THE CARDIAC CYCLE Contraction (Systole) and relaxation(Diastole) of the heart.

BLOOD PRESSURE Force exerted on the arterial walls with each heartbeat. Measured with a sphygmomanometer.

The volume of blood pumped with each heartbeat. (Ave 70 ml) STROKE VOLUME The volume of blood pumped with each heartbeat. (Ave 70 ml)

HEART RATE Heart rate (HR) is the number of heart beats in one minute.

CARDIAC OUTPUT SV (stroke volume) X HR (heart rate) = CO Ave SV – 70 X Ave HR – 80 = 5600 mL

FACTORS THAT AFFECT CARDIAC OUTPUT