-Blood is pumped by the heart

-Blood is then transported through blood vessels

-Blood circulates through lungs to replenish oxygen and dispose of CO2

-Blood circulates through kidneys to remove other waste products (urea)

-Nutrients absorbed into blood as it passes through GI tract

-The heart is approximately the size of a fist

-Weighs less than 1 pound

-250-350 grams

-Lies within the mediastinum

The medial cavity of the chest (thorax)

-Most of the heart lies in the left chest

-PMI - Point of maximal intensity

Where the apex of the heart contracts the chest wall

Can feel your heart beating

(Peri = around; cardio = heart)

Encloses the heart in a double walled sac

Fibrous Pericardium

Serious Pericardium

-Outer, superficial part of the double walled sac

-Three main functions

protect the heart

anchor it to surrounding structures

prevent overfilling of the heart with blood

Pericardium cont 

deeper to the fibrous layer

serous layer

-parietal layer

-visceral layer

Found between the parietal and visceral layers

contains a film of pericardial fluid

Reduces the friction between the parietal and visceral surfaces as the heart beats

Inflammation of the pericardium

Build up of percardial fluid

May become life threatening because fluid compresses the heart

-cardiac tamponade (blockage or closure)

Deep pain in the sternum

Can lead to adhesions so the pericardia stick together impeding heart activity

3 Layers:

Superficial to deep

-Epicardium

-Myocardium

-Endocardium

Most superficial layer of the heart wall

Visceral layer of pericardium

Where fat accumulates

-esp in elderly

-Middle layer of heart wall

-Mostly cardiac muscle

-Forms bulk of the heart

-Contracting layer

Deepest Internal layer

White sheet of endothelium tissue on layer of connective tissue

Lines the heart chambers and valves

-Right Atrium

-Right Ventricle

-Left Atrium

-Left Ventricle

-Left & Right atria receive blood

-Small and thin walled

-Right and left atria separated by the interatrial septum

Right Atria filled by 3 veins

-Superior vena cava

-Inferior vena cava

-Coronary sinus

Left atria filled w/ 4 pulmonary veins

-Make up majority of heart

-Papillary muscles 

Help hold the tricuspid and bicuspid (mitral) valves shut

-Pump of the heart

Eject (push) blood out of the heart

Right Ventricle:

-Forms most of the hearts anterior surface

-Pumps blood into the lungs for gas exchange

Left Ventricle:

-Forms most of the hearts posterio-inferior surface

-Ejects blood into the aorta