The Anatomy of the Heart

Gareth Yeung

Overview

Large conical shaped muscular organ

Size depends on size of person Usually size of clenched fist

250g = Women 300g = Men

Located within the chest

Where is the heart?

Martini, F., Nath, J. (2011) Fundamentals of Anatomy & Physiology (9th Edition). 9 Edition. Benjamin Cummings

Where is the heart?

Martini, F., Nath, J. (2011) Fundamentals of Anatomy & Physiology (9th Edition). 9 Edition. Benjamin Cummings

The Pericardium

Outer layer – Parietal Layer Inner Layer – Visceral Layer

Cavity – Pericardial Cavity

Serous Fluid provides lubrication for the two layers

The Pericardium

Martini, F., Nath, J. (2011) Fundamentals of Anatomy & Physiology (9th Edition). 9 Edition. Benjamin Cummings.

Tortora, G., Derrickson, B. (2011) Principles of Anatomy and Physiology (Tortora, Principles of Anatomy and Physiology). 13 Edition. Wiley.

The Heart Wall

Divided into three layers – The Epicardium (external layer) The Myocardium (middle layer) The Endocardium (inner layer)

The Epicardium

Here is where the coronary arteries lie before entering the myocardium

Contains a lot of fat for protection

The Myocardium

Cells arranged in circular bundles that link all the chambers together

This affects the way the heart contracts

Martini, F., Nath, J. (2011) Fundamentals of Anatomy & Physiology (9th Edition). 9 Edition. Benjamin Cummings

The Endocardium

Lies inside the heart Thin sheet of endothelium on top of

connective tissue Lines the heart chambers and blood

vessels entering and leaving the heart.

The Heart Wall

Tortora, G., Derrickson, B. (2011) Principles of Anatomy and Physiology (Tortora, Principles of Anatomy and Physiology). 13 Edition. Wiley.

The Chambers of the Heart

Four chambers in the Heart

Two Atria – Pump blood into Ventricles

Two Ventricles – Pump blood out of the Heart.

Right Atrium

Feeds right ventricle Fed by 3 main vessels:

Superior Vena Cava Inferior Vena Cava Coronary Sulcus

Contains de-oxygenated blood ~ 75% saturation Sino-atrial Node & Atrioventricular Node Contains depression called Fossa Ovalis Pressure = 4 mmHG

Martini, F., Nath, J. (2011) Fundamentals of Anatomy & Physiology (9th Edition). 9 Edition. Benjamin Cummings

Left Atrium

Feeds left ventricle Fed by 4 blood vessels:

Two from left Two from right

Smaller than right atrium Contains oxygenated blood ~ 97-99% saturation Pressure = ~ 8 mmHG

Right Ventricle

‘Crescent’ shaped Fed by the RA through the Tricuspid Valve Pumps blood into pulmonary system

through the pulmonary valve and into the pulmonary artery

Unique band of muscle – Moderator band Pressure:

Peak Systole = 15–30 mmHG End Diastole = 3–8 mmHG

James Publishing, (2010), Cross-section of the ventricles of the heart, which are important to blood movement [ONLINE]. Available at: http://www.jamesdisabilitylaw.com/images/Cross_Section_Ventricles.gif [Accessed 15 April 12].

Left Ventricle

‘Conical’ shaped Fed by the LA through the Mitrial Valve Pumps blood into circulatory system

through the aortic valve and aorta Much thicker muscle mass Pressure:

Peak Systole = 90–140 mmHG End Diastole = 5–12 mmHG

The Atrioventricular Valves

Chordae Tendineae attached to free edge of cusp

Papillary muscles anchor tendons to the heart

Tendons and muscle help prevent inversion of cusps

Tortora, G., Derrickson, B. (2011) Principles of Anatomy and Physiology (Tortora, Principles of Anatomy and Physiology). 13 Edition. Wiley.

The Pulmonary Artery & The Aorta

Three layers: Tunica Intima (Inner) Tunica Media (Middle) Tunica Externa (Outer)

Carries blood away from heart = artery PA is only artery to carry de-oxygenated

blood Carries blood to lungs Aorta transports blood to body cells Two coronary arteries branch off here

References

James Publishing, (2010), Cross-section of the ventricles of the heart, which are important to blood movement [ONLINE]. Available at: http://www.jamesdisabilitylaw.com/images/Cross_Section_Ventricles.gif [Accessed 15 April 12].

Klabunde, R. (2011) Cardiovascular Physiology Concepts. Second Edition. Lippincott Williams & Wilkins.

Martini, F., Nath, J. (2011) Fundamentals of Anatomy & Physiology (9th Edition). 9 Edition. Benjamin Cummings.

Tortora, G., Derrickson, B. (2011) Principles of Anatomy and Physiology (Tortora, Principles of Anatomy and Physiology). 13 Edition. Wiley.