The Cardiovascular System

Location of the heart

Mediastinum (behind the sternum and angled slightly to the left)

Overall structure of the heart

• 4 chambers (2 atria, 2 ventricles)

• 2 sets of valves (2 x atrioventricular valves, 2 x semilunar valves)

Remember: tRIcuspid has RI in it for RIght side or LAB RAT (Left Atria Bicuspid, Right Atria Tricuspid)

Function of the heart

Pump blood around the body

Flow of blood through the heart

Layers of the heart wall

1. Epicardium (aka visceral pericardium)

2. Myocardium

3. Endocardium

Functions of the layers of the heart wall

1. Epicardium = outer layer supports blood vessels + nerves

2. Myocardium = middle layer of cardiac muscle

3. Endocardium = inner layer of squamous epithelium continuous with endothelial linings of blood vessels (prevents blood sticking to walls)

Major blood vessels serving the heart

Differences in Systemic and Pulmonary circulations

1. Blood Pressure

• Pulmonary circuit: low pressure due to delicate respiratory system

• Systemic circuit: high pressure due to oxyegn demand of cells all around body

Functions of blood vessels

Transports blood, which carries nutrients, gases, waste products, hormones, immune cells, etc

Breakdown of epithelial layer

Blood sticks to wall of blood vessels = clots = stroke/ pulmonary embolism

Myo

Muscle

Epi

Outer / upper / top layer

Endo

Inside / under/ bottom

Cardium

Anything to do with the cardiovascular system

Function of valves

Prevent backflow of blood by opening and closing in response to pressure changes

Location of valves

• atrioventricular valves: between the atria and ventricles

• semilunar valves: between ventricles and arteries leaving the heart

Heart nourishment

an area behind the aorta where he coronary arteries can get the best blood possible.

Coronary artery

supplies the heart with everything that it needs to function as a pump

Coronary arteries

Both located in the epicardium and supply myocardium

1. Left Coronary Artery: branches into 2 branches called

• Anterior interventricular artery and circumflex artery)

2. Right Coronary Artery: divides into 2 branches called

• right marginal artery

• posterior interventricular artery

Coronary Veins

• Carry away waste products

• collects Venus blood

Coronary Sinus

• Empties blood into right atrium

• Contains 3 large tributaries: great cardiac vein, middle cardiac vein, lesser cardiac vein