5 The heart Flashcards
(95 cards)
What is the shape of the pericardium?
Conical shaped
What is the pericardium continuous with?
With pretracheal layer of cervical fascia superiorly
Nb function of pericardium
Shock absorber (cardiac seatbelt), prevents over expansion when blood increases and limits heart movements
Layers of pericardium
- Fibrous
- Serous
Outermost layer of pericardium
Fibrous
Describe fibrous layer
Irregular dense connective tissue with much collagen
Function of fibrous layer
To anchor heart to diaphragm and the great vessels
Serous pericardium layers
- Parietal
- Visceral
What is the parietal layer attached to?
Fibrous pericardium
What is the visceral attached to?
To surface of the heart and aorta, pulmonary trunk, vena cavae (epicardium)
What do the lines of reflection between visceral and parietal pericardium form?
Two pericardial sinuses – oblique and transverse
What is the pericardial cavity filled with?
With serous pericardial fluid, really a potential space containing 10-20 mls of pericardial fluid
Function of pericardial cavity being lubricated?
Prevents friction as the heart beats
Inflammation of the pericardium
Pericarditis
Where is the transverse pericardial sinus located?
Anterior to the SVC and post to the Ascending aorta and Pulmonary Trunk
What does the transverse pericardial sinus seperate?
The arterial vessels (A, PT) and the venous vessels (SVC, PV)
What can the transverse sinus be used to locate?
The arteries of the heart during coronary artery bypass grafting.
What is the oblique sinus bound by?
The lines of reflection of the serous pericardium onto the
inferior vena cava and the left and right pulmonary veins
Cardiac tamponade long
The relatively inextensible fibrous pericardium can cause pericardial effusion (increased fluid) in the pericardial cavity. Increased pressure. The chambers can become compressed, thus compromising cardiac output.
Haemopericardium (bloodin the pericardium) and pericarditis
Arterial blood of pericardium
- Internal thoracic - Musculophrenic and pericardiophrenic branches
- Descending thoracic aorta from bronchial, oesophageal and superior phrenic arteries
Venous blood of pericardium
Venous drainage to azygous system
Nerves of pericardium
Phrenic nerve to fibrous and serous pericardium / visceral is vagus and sympathetic trunks (insensitive to pain)
3 layers of the heart from out - in
- Epicardium
- Myocardium
- Endocardium
Describe epicardium
- Visceral layer of pericardium
- Adipose and fibroelastic tissue