The Human Heart Structures & Functions

*Note… Words highlighted in blue or red indicate the oxygenation of the blood flow through that structure. RED=oxygenated blood BLUE=deoxygenated blood L side heart=oxygenated blood R side heart=deoxygenated blood

Heart Functions to pump blood to all parts of the body Muscle tissue = myocardium Size of a closed fist 5” long and 3.5” wide Weighs about oz

Heart Located in the Thoracic Cavity between the lungs, in front of the thoracic vertebrae and above the diaphram. Lies centrally located, but the apex is slightly to the left midline. Apex

Structures Pericardium Myocardium Endocardium Ventricular Septum 4 chambers: R & L atria R & L ventricles

Heart Structure- Pericardium: double layer of fibrous tissue (outer layer) Myocardium: cardiac muscle tissue (middle layer) Endocardium: smooth muscle tissue lining the interior

Structures leading to and from the heart Superior & Inferior Vena Cava: large veins which brings deoxygenated blood to the R atrium from all parts of the body. Pulmonary Artery: takes blood away from the R ventricle to the to the lungs for oxygen.

Structures leading to and from the heart…cont’ Pulmonary veins: which bring oxygenated blood to the heart from the lungs. Aorta: takes blood away from the L ventricle to the rest of the body.

Valves of the Heart Tricuspid Valve: structure that is positioned between the R atrium and R ventricle. It has this name because there are 3 cusps (points) of attachment. It allows blood to flow from the R atrium into the R ventricle, but not in the opposite direction.

Valves of the Heart…cont’ Mitral Valve: located between the L atrium and L ventricle. Blood flows from the L atrium to the L ventricle, while backflow from the ventricle to the atrium is prevented. Closing of the valves produces heart sounds “lubb-dubb”

Valves of the Heart…cont’ Semilunar Valves Aortic Semilunar Valve: is at the orafice of the aorta. This valve permits blood flow out of the L ventricle to the aorta, but not backwards into the L ventricle. Pulmonary Semilunar Valve: is found at the orafice of the pulmonary artery. It lets blood flow from the R ventticle into the pulmonary artery, and then into the lungs.

INSIDE CHAMBER

Labeled Structures Superior Vena Cava R Atrium I Inferior Vena Cava R Ventricle Aorta Pulmonary Artery L Atrium L Ventricle Ventricular Septum

Valves of the Heart Tricuspid Valve Pulmonary Semilunar Valve Mitral Valve Aortic Semilunar Valve

Summary R & L Atria R & L Ventricle Pulmonary Artery Aorta Mitral Valve Tricuspid Valve Superior & Inferior Vena Cava Pulmonary Semilunar Valve Aortic Semilunar Valve Ventricular Septum *R side heart = deoxygenated blood *L side heart = oxygenated blood