Pericardium = outer covering
Fibrous Pericardium
Visceral Pericardium
X

​X

​Layers of the Heart

Walls of Heart
X
X
Myocardium
Endocardium

​

What is the function of the following membranes?

Fibrous pericardium - provides protection and anchors heart in place
Serous pericardium - lubricates to reduce friction

​carries blood to lungs (picks up oxygen and releases carbon dioxide)

​​Pulmonary Circuit

​carries blood to body tissues and back (drops of oxygen and picks up Carbon dioxide)

​​Systemic Circuit

1. Two atria (right and left)

​2. Two ventricles (right and left)

Left Atrium and Left Ventricles = O2 blood
Right Atrium and Right Ventricle = no O2 in blood
The septum separates the two sides of the heart.

​4 Chambers of Heart

There are two sets of valves:

​1. Atrioventricular valves - between atria and ventricles
Tricuspid Valve
Bicuspid/mitral valve
2. Semilunar valves - between ventricles and major blood vessels.
Pulmonary Valve
Aortic Valve

​Major internal strutures of the heart.

Generally, think A before V...it works with the pulmonary arteries and veins as well as atrium and ventricles. ​

​General flow of blood through heart

Trace the path of the intrinsic conduction system.

SA node --> AV node --> AV bundle --> bundle branches --> Purkinje fibers

​

​Physiology of the heart

​Atrial Contraction (ventricles fill)
AV valves close making "lub" sound

​​Diastole (Relax)

​Isovolumetric contraction of ventricles
Ejection Phase
similunar valves close making "dup"sound
Isovoumetric relaxation

​​Systole (Contract)

Cardiac Output =

heart rate x stroke volume

Stroke Volume - volume of blood pumped out by a ventricle in a heart beat (average is 75 mL)
Heart Rate - number of times the heart beats per minute

​

​How can CO change?