Lecture 2: Heart Layers and Coverings

Excess fluid/blood leaks into the heart and compresses it, so you have limited pumping ability (and blood is not pumped properly)

Cardiac Tamponade

After the Visceral layer, there is the heart. The heart is composed of 3 layers. What are they?

Epicardium Myocardium Endocardium

What is the Myocardium? Function?

It is the thick layer of cardiac muscle within the heart; it is the reason the heart contracts (beats)

Spiral bundles of contractile cardiac muscle cells;

Myocardium

Pericardial Sac vs Pericardial Cavity

Pericardial Sac: double-layer sac that is on top of the heart; It is composed of: 1) Fibrous Pericardium (lines the cavity) 2) Serous Pericardium: (Parietal: layer next to fibrous layer) (Visceral: layer that touches the organ--heart) Pericardial Cavity: is a space in between the Parietal and Visceral layers of the Pericardial Sac; it reduces friction. Pericardial Sac A: Fibrous Pericardium Serous Pericardium B: Parietal layer C: Pericardial Cavity (space) D: Visceral layer

What is a key sign of Pericarditis?

Pericardial friction rub (a creaking sound) heard by the stethoscope

inflammation of the Pericardium (membrane surrounding the heart)

Pericarditis

What are the 2 sublayers of the Serous Pericardium

The Parietal layer and the Visceral layer

Differentiate between the Parietal and Visceral layers of the heart.

The Parietal layer lines the internal surface of the Fibrous Pericardium. The Visceral layer actually touches the organ; it is on the external surface of the heart.

The Parietal layer and The Visceral layer are separated by a fluid-filled cavity to decrease friction; what is this cavity called?

The Pericardial Cavity

What does the heart sit in?

The Pericardial sac (Pericardium)

The double-walled sac that he heart sits in is called what?

The Pericardium (The Pericardial sac)

What cavity do the lungs sit in?

The Pleural cavity

Crisscrossing, interlacing layer of connective tissue that: - anchors cardiac muscle fibers - supports great vessels and valves - limits the spread of action potentials to specific paths What is this?

The cardiac skeleton

Pericardial friction rub (a creaking sound heard by the stethoscope) is a key sign of Pericarditis. Why is this sound made?

The membrane surfaces have roughened

This layer of the Pericardium is made up of tough, dense connective tissue. It protects the heart and anchors to surrounding structures; it prevents overfilling. Which layer is this?

The superficial Fibrous Pericardium

The Myocardium is around the Atria and Ventricles; it squeezes blood downward/upward.

downward: from atria to ventricles

What is Pericarditis?

inflammation of the Pericardium (membrane surrounding the heart)

What is the Mediastinum?

the medial cavity of the thorax where the heart is enclosed

What is the cardiac skeleton?

Crisscrossing, interlacing layer of connective tissue that: - anchors cardiac muscle fibers - supports great vessels and valves - limits the spread of action potentials to specific paths

Differentiate between: Epicardium Myocardium Endocardium

Epicardium: above the heart = same as the visceral pericardium Myocardium: the thick layer of muscle Endocardium: the inside of the heart; inside lining of the heart chambers

What is Cardiac Tamponade?

Excess fluid/blood leaks into the heart and compresses it, so you have limited pumping ability (and blood is not pumped properly)

What are the 2 layers of the Pericardium?

The Superficial layer is called the Fibrous Pericardium and it is made up of dense connective tissue; it's very tough. The Deep layer is called the Serous Pericardium; it is composed of thinner connective tissue and secretes serous fluid to reduce friction.

This layer is composed of thinner connective tissue and secretes serous fluid to reduce friction. This layer is composed of 2 sublayers.

The deep Serous Pericardium

What causes Cardiac Tamponade?

sometimes the aorta can leak blood and fluid if it is damaged