Thrombosis and blood coagulation are dynamic processes necessary for the maintenance of circulatory hemostasis. As well as preventing life threatening loss of blood during surgery or accidental wounding, the process is concerned with the more subtle preservation of the integrity of small blood vessels and quickly plugs vessels when a solution of continuity occurs. Hemostasis depends on a combination of three factors. These are the integrity of the capillary and blood vessel wall, circulating blood platelets and a number of clotting factors of which eleven have been isolated. Inefficiency of one or a combination of these factors leads to athrombocytopenic purpura, thrombocytopenic purpura, hemophilia and various other abnormal bleeding states.

Dyspnoea is a common, if not the commonest symptom, of thyrotoxicosis (Wayne) and cardiovascular overactivity is recognized as a cardinal sign of the disease. Despite the prominence of these manifestations the underlying physiology is poorly understood. Probably the major reason for this is lack of data. Stein, et al.,(l961) have recorded a relatively comprehensive study of pulmonary function on thirteen patients at rest and on exercise. Their findings are discussed later but they, in common with all other investigators, did not report on the exercise diffusing capacity.

The man produced radiation had been with us for nearly three-quarters of a century. It represents an element which has significant impact on nearly every phase of human life. In the latter part of last century, the experiments with vaccum dischargers have led to the discovery of X-rays by Roentgen in 1895. This was soon followed by Becherel's (1896) discovery of radiation from radiactive materials. Within months it was recognized that each of these radiation could have injurious effect upon persons exposed to it. The increasing incidence of radiation damage had culminated in the establishment of International Commission of Radiological Protection in 1928.

There has been much development in the field of respiratory physiology within the recent past, and this has been accelerated by the availability of better instruments for the purposes of making measurements. Since Hutchinson introduced the spirometer in 1846, the introduction of each new instrument has revealed a new area into which efforts of research, both clinical and purely physiological, have been directed. One of the most powerful, and yet the most simple tests of respiratory dynamic capability is the Forced Expiratory Volume, consisting of a maximal forced expiration following a maximal inspiration. It has been demonstrated that this test is a sensitive indicator of respiratory airway resistance.

The cutaneous burn and the problem of effective therapy, especially in the more extensive ones, is profound and interest in it dates back many decades. In this paper, we are presenting the problem of cellular injury resulting from the application of heat to living tissue, otherwise known as a "thermal burn". There are numerous varieties of thermal burns aptly named according to the physical nature of the heat emitting agent. Amongst these are electrical burns resulting from contact with a “live electric current”, flash burns secondary to intense radiant energy, flame burns produced by contact with flames from any flamable agent, and scald burns resulting from contact with high temperature liquids to mention only a few.

The importance of removing the epicardium for myocardial revascularization was recognized by Beck in 1935. Beek and Tichy (1935) recommended removal of the epicardium irrespective of the graft or material used, be it talc powder, pericardium, pericardial fat, mediastinal tissue, pleura, etc. Beck believed that the epicardium was a barrier to the development of extra-coronary vessels. Further, he stated that a pressure differential was necessary to promote anastomoses between the cardiac and extra-cardiac vascular beds.

From 1927 to 1930 various groups of investigators demonstrated that adrenal cortical extracts were capable of prolonging the life of adrenalectomized cats (1-4) and dogs (5). Subsequently, Wintersteiner, Vars and Pfiffner (6,7) showed that after the removal of various crystalline substances from adrenal cortical extracts, a non-crystallizable amorphous residue remained which was more active than the separated crystalline components in maintaining the life of an adrenalectomized dog. Kendall, Mason and associates (8) also found that the most physiologically active traction remained in solution and that it was at least ten times more active than compound B. similar findings were reported by Kuizenga and Cartland (9).

A knowledge of the role played by the papillary muscles in the activity of the heart and especially in the closure and function of the mitral valve has become important to the surgeon involved in surgery of the cardiac valves. Current surgical techniques tend to destroy the normal relationships of the papillary muscles and there is some clinical evidence (16.20) that this is detrimental to the cardiac dynamics. Current understanding of the importance of the papillary muscle mechanism is limited by a lack of information describing the activities of the papillary muscles. It is the object of this thesis to investigate the activity of the papillary muscles and to relate these observations to an understanding of the role of the papillary muscles in atrioventricular valve function.

During the past few years, the function of the thymus gland has been greatly clarified. It is now known to play an important role in the development of immunological competence. However, less is known about that role, if any, the thymus plays in the maintenance of immune function during adult life. Because of the bearing of immune function on tissue transplantation and because of the possible role of the thymus in immune function, this gland may be of importance in a better understanding of organ and tissue rejection. Similarly, modification or removal of the thymus, with or without other treatment, may be of value in modifying the homograft rejection phenomenon. If any rational attempt, to alter homograft rejection by manipulation or extirpation of the thymus, is to be made, a more thorough knowledge of the function of the adult thymus is necessary.

Anatomically the lung consists of two conducting systems to bring the inspired air and venous blood into contact. The effectiveness of gas exchange is largely dependent on the efficiency of these distribution systems. If parts of the lung are ventilated but not perfused, or perfused but not ventilated, no gas exchange will occur in these areas. Furthermore, ventilation in excess of perfusion, or perfusion in excess of ventilation are relatively inefficient. The optimum distribution is clearly when the quantities of ventilation and perfusion are matched, that is, the Ventilation/Perfusion ratio is equal in all lung units. To predict gas exchange it is therefore necessary to know not only the total quantities of alveolar ventilation and pulmonary capillary blood flow, but also their distribution.