3a pericardium Flashcards
What is the pericardium?
The pericardium is a membrane that covers the heart and is positioned within the middle mediastinum of the thorax.
What are the two layers of the pericardium?
- An outer fibrous layer
- An inner thin serous layer that reflects onto the surface of the heart.
What is the fibrous pericardium?
The fibrous pericardium is the outer layer, continuous with the great vessels adventitia, and blended inferiorly with the central tendon of the diaphragm.
What is the serous pericardium?
The serous pericardium is contained within the fibrous pericardial sac and consists of a double layer: visceral layer (epicardium) and parietal layer.
What are the functions of the pericardium?
- Protection from infection
- Fixes the heart in the mediastinum and limits its motion
- Lubrication
- Prevents rapid overfilling of the heart.
What is cardiac tamponade?
Cardiac tamponade is a potentially fatal situation when blood or fluid accumulates in the pericardium, compressing the heart and impeding its blood supply.
What are common causes of cardiac tamponade?
Common causes include pericarditis, trauma, heart surgery, dissecting aortic aneurysm, end stage lung cancer, or acute myocardial infarction.
What is pericardiocentesis?
Pericardiocentesis is a procedure to remove fluid from the pericardium to reduce pressure.
What is pericarditis?
Pericarditis is the inflammation of the pericardium.
What is the structure of the heart’s anterior surface?
The anterior surface is formed mostly from the right ventricle and is related anteriorly to the sternum and ribs.
What forms the inferior surface of the heart?
The inferior surface is formed mostly by the left ventricle and is related inferiorly to the centre of the diaphragm.
What is the base of the heart?
The base is situated on the posterior aspect, directed towards the vertebrae T6-9, formed mostly from the left and partly from the right atrium.
Where is the apex of the heart located?
The apex lies posterior to the 5th intercostal space in the midclavicular line and is directed antero-inferiorly and to the left.
What is the fibrous skeleton of the heart?
The fibrous skeleton is a supporting structure made of dense collagen that forms four fibrous rings around the valve openings.
What is the role of intercalated discs in cardiac muscle?
Intercalated discs separate cardiac muscle cells, holding them together and allowing electrical excitation to pass between cells.
What structures are found in the right atrium?
Key structures include the atrioventricular orifice, AV node, crista terminalis, fossa ovalis, interatrial septum, opening of the coronary sinus, pectinate muscles, right auricle, and SA node.
What structures are found in the left atrium?
Key structures include the atrioventricular orifice, fossa ovalis, interatrial septum, left auricle, and pectinate muscles.
What structures are found in the right ventricle?
Key structures include the atrioventricular orifice, tricuspid valve, chordae tendineae, conus arteriosus, interventricular groove, interventricular septum, moderator band, papillary muscles, pulmonary valve, and trabeculae carneae.
What is the aortic valve?
The aortic valve is a semilunar valve located between the left ventricle and the aorta.
What is the function of chordae tendineae?
Chordae tendineae, meaning ‘tendinous cords’, attach to the cusps of the atrioventricular valves and to the papillary muscles of the ventricle. They hold the valves in place and prevent reflux.
What are papillary muscles?
Papillary muscles extend from the ventricular walls and are attached to the chordae tendineae. They prevent prolapse of the atrioventricular valve cusps.
What is the pulmonary valve?
The pulmonary valve is a semilunar valve located between the right ventricle and the pulmonary trunk.
What are trabeculae carneae?
Trabeculae carneae, meaning ‘meaty ridges’, are irregular muscular columns found on the internal surface of the ventricles.
What is the atrioventricular orifice (left)?
The atrioventricular orifice (left) is the aperture through which blood flows from the left atrium to the left ventricle, where the bicuspid (mitral) valve is positioned.
