Cardiac physiology

Heart is located…

Within the mediastinum just above the diaphragm.

The heart is enclosed in

A pericardium

The heart is

A hollow muscle double pump

The heart is divided into

Four chambers

Left and right chambers of the heart have

A collecting chamber (an atrium) and a pumping chamber (a ventricle)

Collecting chamber

Atrium

Pumping chamber

Ventricle

There are three principal circulatory divisions in the cardiovascular system

systemic circulation, pulmonary circulation, and coronary circulation

Systemic circulation

Carries oxygenated blood from left ventricle through the body and returns venous blood to the right atrium

Pulmonary circulation

Carries venous blood from the right ventricle through lungs and delivers oxygenated blood through 4 pulmonary veins into the left atrium

In lungs, blood

Undergoes oxygenation

Coronary circulation

Delivers oxygenated blood for the heart through coronary arteries

Venous blood from the heart through cardiac veins

Collects into the coronary sinus and empties into the right atrium

Both pumps contract at the same time,

Both sides pump equal volumes of blood with each cycle systole and diastole

Contraction

Systole

Relaxation

Diastole

General organization of the circulatory system

1. Closed system

2. Heart

3. Arterial System

4. Venous System

5. Microcirculation

6. Systemic circulation

7. Pulmonary circulation

Blood movement through the Heart

Systemic Circulation (venous blood) → Superior Vena Cava/ Inferior Vena Cava → Right Atrium → Right Ventricle → Pulmonary Arteries (L/R) → Pulmonary Circulation → Pulmonary Veins (4) → Left Atrium → Left Ventricle → Aorta → Systemic Circulation (arterial blood)

Heart wall morphology

1. Pericardium

2. Epicardium

3. Myocardium

4. Endocardium

Pericadium

Composed of fibrous pericardium + visceral and parietal layers

Epicardium

Superficial visceral layer of the serous pericardium

Myocardium

Composed of contractile cells

Part which actually contracts

Contractile cells