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 = myocardiumSize of a closed fist 5” long and 3.5” wide

Weighs about 12-13 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 StructuresSuperior Vena Cava

R Atrium

IInferior Vena Cava

R Ventricle

Aorta

Pulmonary Artery

L Atrium

L Ventricle

Ventricular Septum

Valves of the Heart

Tricuspid Valve

PulmonarySemilunar 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