One of the first challenges for aspiring surgeons to negotiate is the intercollegiate MRCS examination, which has replaced similar examinations previously run by the four Royal Surgical Colleges. The first edition of Fundamentals of Surgical Practice has become a recommended and standard text for the MRCS examination largely due to the reputation of its contributors. As editors of the second edition we are delighted that the majority of our authors have signed up to a revision and update of their chapters. There are some new contributors and some of our senior authors have revised their chapters with junior colleagues attuned to modern surgical thinking.

Technological aspects of surgery have undergone rapid change in the last two decades. A parallel change has taken place in the educational concepts underpinning transfer of basic knowledge into surgical practice. The knowledge base itself may not have changed a great deal but its method of presentation has. Therefore, we have selected authors with a gift for imparting the enthusiasm of their specialist interest in a straightforward and easily understood way but without missing out on the detail. In this edition the alimentary system has been expanded into two chapters on Upper gastrointestinal and Lower gastrointestinal surgery and a separate chapter on Hernia management has been added to emphasise the importance of surgery of the abdominal wall as an expanding area of specialist interest.

CARDIOVASCULAR SYSTEM

Cardiac anatomy

The heart has four chambers, four valves, and specialized conduction tissue. It is generally referred to as having left and right-sided chambers, but in humans the interatrial septum and inter-ventricular septum are located in a plane some 45° from the sagittal plane (Fig. 8.1). The right atrium and ventricle are therefore located anterior and to the right of the corresponding left atrium or ventricle. It is useful to bear this in mind when visualizing the cardiac chambers through echocardiograms (ECHO) or when assessing traumatic injuries to the chest wall.

Cardiac valves

The aortic and pulmonary valves are similar in structure and function, and consist of three components:

The aortic valve leaflets are referred to by clinicians as the left coronary, right coronary, and non-coronary leaflets. The fibrous annulus is shaped like a three-pronged coronet from which the valve leaflets are suspended. Valve stenosis may arise when the valve leaflets are fused or stiff and the annulus narrows; valve incompetence results from abnormalities of the valve leaflets and/or dilation of the annulus. The sinuses of Valsalva are important for initiating valve closure. They prevent the valve leaflets from being pressed flat against the aortic wall during systole, and eddy currents within the sinuses help initiate valve closure in diastole.