Cardiovascular System

Location of the heart

Within the thorax, lungs on both sides

Apex towards the left hip(bottom of the heart)

Belong the 2nd rib(top of the heart)

Rests on diaphragm

Double sac

Encloses the heart like a bag (2 layers)

1. visceral pericardium(inner)-directly hugs the heart

2. Parietal pericardium(outer)-anchored at sternum and diaphragm

3 layers of heart wall

1.Epicardium-visceral pericardium

2.Myocardium-cardiac muscle tissue, the contractions start here

3.Endocardium-thin sheets, lines inner heart chambers, continuous with blood vessels

Septum

Separates right and left of the heart

Atria-thin walled, upper chambers, receives blood

Ventricles-thick, muscular lower chambers, rushes blood out of the heart through arteries

Autonomic nervous system

(Brain)- the checks and balances to high and low heart rate depending on various factors. It helps to control the rate of the heart beat but it doesn’t initiate cardiac cycle

Intrinsic conduction system

(Nodal system)-special tissue within the heart and causes muscle to depolarize in 1 direction (a-v)

Fibrillation

Lack of adequate supply of blood to the heart and the heart may become so uncoordinated

Tachycardia

Rapid heart rate

Bradycardia

Slow heart rate

Lub sound

closing of av valves

Dub sound

Semi lunar valves closing

Stroke volume

Volume of blood pumped with each beat

Cardiac output

Amount of blood pumped out of each side of the heart per min

Starlings law

Factor which controls stroke volume is how much cardiac muscle cells are actually stretched before contraction