Structure of the pericardium Flashcards
Pericardium
a fibrous serous fluid filled sack
What foes the pericardium surround
the muscular body of the heart as well as the root of the great vessels
What else does the pericardium attach to?
it is also attached to the central tendon of the diaphragm
The pericardium is mad up of 2 layers:
fibrous pericardium
serous pericardium
fibrous pericardium
- The tough tough external layer
serous pericardium
- thin internal layer
Functions of the pericardium
- To fix the heart in the mediastinum
- To limit the motion of the heart
- To prevent over-filling of the heart
- For lubrication - this layer of fluid between the two pericardium layers reduces the friction made by the heart
- For protection from infection
Fibrous pericardium
(tough superficial layer)
– Function: Protects, anchors, & prevents overfilling
Serous pericardium
(deep 2-layered)
Visceral layer (epicardium) on
external surface of heart Separated by fluid-filled pericardial cavity
(Function: decreases friction)
– Parietal layer lines internal surface of fibrous pericardium
Function: providing lubrication which facilitates movements of heart within pericardial sac.
Fibro-serous sac
- Double layer
- Surrounds heart
Superior:
Covers heart and beginning of major blood vessels
Inferior:
Attached to diaphragm
Layers of the pericardium:
- Fibrous pericardium
- Serous parietal pericardium
- Pericardial space
- Serous visceral pericardium (epicardium)
- Myocardium
- Endocardium
Fibrous pericardium:
- Is the outer layer
Superior attachment of the fibrous pericardium
continuous superiorly with the tunica of the great vessels entering and leaving the heart and with the pre-tracheal layer of deep cervical fascia
Anterior attachment of the fibrous pericardium:
Posterior surface of the sternum
- via sternopericardial ligaments
Posterior attachment of the fibrous pericardium:
Bound by loose connective tissue to structures in the posterior mediastinum
Inferior attachment of the fibrous pericardium:
Continuous inf. with the central tendon of the diaphragm
- attaches via pericardiophrenic ligament
Serous pericardium consists of 2 layers:
- Outer parietal layer
- inner visceral
The inner visceral layer is also called the
epicardium
Pericardial cavity
potential space between the parietal and visceral layers
What does the pericardial cavity contain, and what is its function?
- It normally contains a thin film of fluid
- that enables the heart to move and beat in a frictionless environment
Must be able to draw!
The wall of the heart is made up of the
- Epicardium (visceral)
- Myocardium
- Endocardium
Forms the bulk of the heart and contains the cardiac muscles
Myocardium
Sheet of simple squamous epithelium
Endocardium
Pericardial space contains 2 sinuses:
- Oblique pericardial sinus
- Transverse pericardial sinus
Are the pericardial sinuses anatomical sinuses
No, not really anatomical sinuses (like nasal sinus) = more passageways that we find in the pericardial space
How is the oblique sinus formed
formed by the reflection of the pulmonary veins onto the heart and is enclosed between the limbs of the inverted U of the venous mesocardium.
where does the oblique sinus lie?
Behind the left atrium and in between the left and right pulmonary veins.
Transverse pericardial sinus
- Tunnel shaped
- separates arteries and veins
Transverse pericardial sinus position
- Lies posterior to the ascending aorta and the pulmonary trunk
- Lies anterior to SVC and Superior pulmonary veins
Main arterial supply of the pericardium:
Mainly through a branch of internal thoracic artery
= Pericardiophrenic artery
Other arterial contributions of the pericardium:
- Branches of the musculophrenic artery
- Oesophageal artery
- Bronchial artery
- Superior phrenic artery
- Coronary arteries also involved, but supplies mostly blood to the epicardium (visceral layer of pericardium)
Venous drainage of the pericardium
- Via pericardiophrenic veins which drains into the bracheochephalic or internal thoracic veins
- Also get drainage into the azygos venous system
Nerve innovation of the pericardium is mostly from
- vagus nerve
- phrenic nerve
Innervation of the outer fibrous and parietal pericardium
- from the phrenic nerve
(C3-5) - Provides motor and sensory innervation to the diaphragm
- Originates from the neck and travels down, through the thoracic cavity
- general source of referred pain
innervation of the visceral pericardium
- from the vagus nerve
- and sympathetic trunk
