19.2 The Heart within the thoracic cavity.

The heart is located within the ____ cavity

thoracic

Thoracic cage

Protective bony framework that encloses both the heart and lungs and supports the thoracic cavity.

The heart is positioned ___to the sternum

posterior

The heart is located ___of the body’s midline

left

The heart is between the lungs within the ___

Mediastinum

Mediastinum

Median space of the thoracic cavity between the lungs

The orientation of the heart is ___

• Slightly rotated such that its right side is located more ANTERIORLY

• Left side is located more POSTERIORLY

Base (of the heart)

The posterosuperior surface of the heart

Apex (of the heart)

The inferior, conical end of the heart

projects anterinferiorly towards the left side of the body with the right ventricle lying on the diaphragm.

Pericardium

A multi-layered fibroserous covering that encloses the heart and the roots of the great vessels.

How many layers does the pericardium have? (from outside to inside)

• Fibrous pericardium

• Parietal layer of the serous pericardium

• Visceral layer of the serous pericardium

Fibrous pericardium

• composed of dense connective tissue that encloses the heart but does not attach to it. Rather, this layer is attached superiorly to the base of the arterial trunks (pulmonary trunk and aorta) and inferiorly to the diaphragm.

Parietal layer of the serous pericardium

• composed of simple squamous epithelium and an underlying delicate layer of areolar connective tissue. This layer adheres to the inner surface of the fibrous pericardium.

Visceral layer of the serous pericardium

• (or the epicardium of the heart), is also composed of a simple squamous epithelium and an underlying delicate layer of areolar connective tissue. This layer forms the external surface of the heart.

The 2 serosal layers are separated by what?

Potential space called the pericardial cavity

What do the 2 layers of serous pericardium produce and release?

serous fluid, into the pericardial cavity. Which has the consistency of an oily mixture, and with every heartbeat it lubricates the serous membranes to minimize friction.

Pericardial sac

Encloses the heart and is a loosely fitting bag that holds the fibrous pericardium and the parietal layer together,

The fibrous pericardium of the pericardial sac does what?

Anchors the heart within the thoracic cavity and prevents the heart chambers from overfilling with blood.