Cardio practical 3+4 wet room Flashcards
How are autonomic motor fibres travelling in the vagus nerves (parasympathetic) and spinal cord segments T1-4 (sympathetic) routed to the heart and coronary arteries?
Via the cardiac/cardiopulmonary plexus situated at the bifurcation of the trachea
What are Purkinje fibres?
The Purkinje fibres are specialised conducting fibres composed of electrically excitable cells that are larger than cardiomyocytes with fewer myofibrils and a large number of mitochondria and which (cells) conduct cardiac action potentials more quickly and efficiently than any other cells in the heart.
-Purkinje fibres allow the heart’s conduction system to create synchronized contractions of its ventricles, and are, therefore, essential for maintaining a consistent heart rhythm.
Where are Purkinje fibres located?
They are located in the inner ventricular walls of the heart, just beneath the endocardium in a space called the subendocardium
Where does the sino-atrial (SA) node lie?
It lies near the opening of the SVC in the right atrium
Where does the atrioventricular (AV) node lie?
It lies in the inferior part of the interatrial septum
Where does the atrioventricular bundle (of his) lie?
It lies within each side of the interventricular septum
Where does the heart lie?
It lies in front of the oesophagus and vertebra T5-T8
What is the surface marking of the apex (apex beat)?
5th intercostal space, midclavicular line
posterior to which bone is the heart situated?
Sternum
Anterior to which four vertebrae is the heart situated?
T5-T8
Upon which structure does the inferior surface of the heart lie?
Diaphragm
Where is the Pulmonary heart sound auscultated?
2nd left space, parasternally
Where is the Aortic heart sound auscultated?
2nd right space, parasternally
Where is the Mitral heart sound auscultated?
5th left space, midclavicullar line (apex)
Where is the Tricuspid heart sound auscultated?
Over lower sternum, (or just to the right of it)
