Thoracic duct

“ Now if we examine in a dog the thoracic duct during digestion, which can easily be done by opening quickly the thorax on the right side, raising the lungs of that side, and by cutting the pleura along the aorta, which allows you to see immediately this canal then very white on account of the chyle that is passing through it, if, I say, we examine the thoracic duct in action, we shall see that the circulation goes on there nearly as in the veins. By opening it then, a more powerful throw of fluid does not indicate a greater velocity than that of the venous blood. ”

“ Intra-thoracic tumors, aneurisms, emphysema, and sclerosis of the [p. 571] lung cause hydrothorax by pressing upon the venous trunks and upon the thoracic duct without producing general dropsy. Chronic diseases, such as cancerous disease, chronic malaria, etc., produce great exhaustion and give rise to general hydræmia. Especially is this the case in chronic disease of the kidneys, such as the several varieties of nephritis and amyloid degeneration, where there has been a loss of albumen for a long time and the blood-serum has been rendered poorer in solid constituents. ”

“ At an early stage in the embryo pig two thoracic ducts are formed, one on either side of the aorta, and the incomplete fusion of these may account for the division often found in man’s duct. In the embryo pig too there have been found two pairs of lymph hearts for a short period. ”

“ The point of the aneurismal needle is to be brought out close to the inside of the artery within its sheath, by which means all danger will be avoided of injuring either the recurrent or the sympathetic nerves which lie behind or to the inside of it. As to the œsophagus, thoracic duct, or thyroid artery, they are not likely to be injured by any common operator ”

“ The study of their development shows that they grow into the tissue as a closed system of minute tubes, which indicates that in all probability they remain permanently closed. If we trace the lymphatic vessels towards the thorax we find that in some part of their course they terminate in structures known as lymphatic glands. From these again fresh lymphatic vessels arise which carry the fluid towards the main lymph-vessel, the thoracic duct. This runs up the posterior wall of the thorax close to the aorta, and finally opens into the junction of the internal jugular and left subclavian veins. ”

“ Another portion is picked up by small structures proceeding from below the mucous surface of the stomach, and from which originate a series of fine tubes that reach at last the lower portion of a common tube, termed the thoracic duct—a tube which ascends in front of the spinal column, and terminates at the junction of two large veins on the left side of the body, at a point where the venous blood, returning. from the left arm, joins with the returning blood from the left side of the head on its way to the heart. ”

“ It will be observed that when the sides are spread apart air flows into the bellows. When they are pressed together the air flows out. If an air-tight sack were hung in the bellows with its mouth attached to the projecting tube, the arrangement would resemble closely the general plan of the breathing organs (Fig. 41) . One respect, however, in which the bellows differs from the thorax should be noted. The thorax is never sufficiently compressed to drive out all the air. Air is always present in the lungs. This keeps them more or less distended and pressed against the thoracic walls. ”

“ When the drainage-tube has completely contracted, the stilette is withdrawn. The drainage-tube is then transfixed with a safety-pin inserted close to the skin, and the superfluous tubing cut off. Pus flows freely from the tube, which now firmly plugs the wound in the abdominal wall and liver, and bridges the peritoneal cavity. When the abscess has nearly emptied itself the usual antiseptic dressing is applied. In operating through the thoracic wall, if deemed desirable, part of a rib may be excised before the trocar is introduced. ”

“ If the thorax be pierced from any point whatever, provided the instrument be directed towards a common centre, A, Plate 1, the lung will suffer lesion; for the heart is, almost completely, in the healthy living body, enveloped in the lungs. So true is it that all the costal region (the asternal as well as the sternal) is a pulmonary enclosure, that any instrument which pierces intercostal space must wound the lung.
As the sternal ribs degenerate into the “false” asternal or incomplete ribs from before, obliquely backward down to the last dorsal vertebra, so the thoracic space takes form. ”

“ Should the lungs be congested with blood, they must be emptied. This object may be attained either by pressing upon the lower part of the thorax, which will have the effect of forcing the blood out through the nostrils and mouth; or else the diaphragm separating the thoracic cavity from the abdomen may be cut through, and the extravasated blood can therefore be got out through the opening. The injection of the thoracic cavity can also be performed through the same opening. ”

“ Quoted by Ashhurst, Hunter recorded a case of gunshot wound, in which, after penetrating the stomach, bowels, and diaphragm the ball lodged in the thoracic cavity, causing no difficulty in breathing until shortly before death, and even then the dyspnea was mechanical—from gaseous distention of the intestines.
Peritonitis in the thoracic cavity is a curious condition which may be brought about by a penetrating wound of the diaphragm. ”

“ Where the trunk of the nerve is entirely obliterated nothing can be done, and in many cases of injuries along the trunk of the recurrent it will be impossible to know that the nerve has not been destroyed in the mechanical lesion.
Paralysis caused by pressure upon the intra-thoracic portion of nerve is beyond the reach of surgical interference. When this is aneurism, disease of the apex of the lung, or pleuritis, as may possibly happen, the paralysis or paresis must of course have a history coeval with the thoracic disease. ”

“ When, in addition to the natural opening of the glottis, a false opening is made in the side at the point K, the air within the lung at I, and external to it in the now open pleural cavity, will stand in equilibrio; the lung will collapse as having no muscular power by which to dilate itself, and the thoracic dilator muscles will cease to affect the capacity of the lung, so long as by their action in expanding the thoracic walls, the air gains access through the side to the pleural sac external to the lung. ”

“ It is evident that congestion of the minute branches of the pulmonary artery would not give to the lung-tissue a bright-red color, and if such a condition exists it must be due to injection of the bronchial vessels. It is by no means proven that such injection ever precedes pneumonic engorgement. In the stage of engorgement that portion of the lung which is involved in the pneumonic process does not collapse when the thoracic cavity is opened. ”

“ These are the mouths of the perspiratory ducts, which convey to the surface the product of the sweat glands. The gland itself is merely a coiled tube, already described as situated deep down in the true skin, and is surrounded with a network of blood-vessels. The duct is simply a continuation of the same tube upward through the cuticle to the surface. It passes out upon the surface of the skin obliquely, thus leaving a small portion of the cuticle overlapping its orifice, forming a sort of valve. ”

“ The upper ends of these numerous involutions unite together and form a string of cells, at first solid, but very soon acquiring a lumen, and becoming a duct which communicates (as it clearly must from its mode of formation) , at numerous points with the pleuro-peritoneal cavity. It is very probable that there is one involution to each segment of the body between the front and hind ends of the Oviduct. This duct is the Wolffian duct, which thus, together with the Oviduct, is formed before the appearance of the external gills. ”

“ This duct arises, as in Teleostei and Amphibia, by the constriction of a hollow ridge of the somatic mesoblast into a canal, which is placed in contiguity with the epiblast, along the line of junction between the mesoblastic somites and the lateral plates of mesoblast. Anteriorly the duct [Pg 816] does not become shut off from the body-cavity, and also bends inwards towards the middle line. The inflected part of the duct is the first rudiment of the pronephros, and very soon becomes considerably dilated relatively to the posterior part of the duct. ”

“ While the principle of the thoracic pneumatic apparatus remains underanged, the motor powers perform their functions capably. The physical or pneumatic power acts in obedience to the vital or muscular power, while both stand in equilibrium; but the ascendancy of the one over the other deranges the whole thoracic machine. When the glottis closes by muscular spasm and excludes the external air, the respiratory muscles cease to exert a motor power upon the pulmonary cavity; their united efforts cannot cause a vacuum in thoracic space in opposition to the pressure of the external air. ”

“ During the formation of the Müllerian duct its anterior part becomes hollow, and attaching itself in front to the peritoneal epithelium acquires an opening into the body cavity. The process of hollowing is continued backwards pari passu with the splitting of the segmental duct. In the female the process is continued till the Müllerian duct opens, close to the Wolffian duct, into the cloaca. In the male the duct usually ends blindly. ”

“ But however much the lungs vary in capacity, or the heart as to position in the respiratory motions, still the lungs are always closely applied to the thoracic walls. Between the pleura costalis and pulmonalis there occurs no interval in health. The thoracic parietes expand and contract to a certain degree; and to that same degree, and no further, do the lungs within the thorax expand and contract. By no effort of expiration can the animal expel all the air completely from its lungs, since by no effort of its own, can it contract thoracic space beyond the natural limit. ”

“ It is irrefutable that the variations in the circumference of the thorax (and, of course, in its diameters) are so considerable that no certain normal mean for a thorax that has breathed, and for one that has not breathed, can be laid down. In most cases the measurements of the thorax are incapable of determining whether the lungs contain air or not. The reasons for these variations is, without doubt, to be referred to the congenital differences in the volume of the osseous thorax; partly, also, to the thickness of the soft parts, particularly of the subcutaneous fat and the thoracic muscles ”

“ There is only one phenomenon positively characteristic of thoracic aneurism, and that is the existence in some part of the thorax of a pulsating tumor other than the heart, which beats isochronously with it, and at least as forcibly, and which at each pulsation expands in every direction. ”

“ When the inflammation has resulted from ascending infection of the salivary ducts, exaggerated sensibility may sometimes be detected throughout the whole length of Stenon’s duct, particularly at the point where the duct crosses the jaw. There is always marked difficulty in moving the head, particularly towards the side, and sometimes in a vertical plane. The head is extended on the neck, and is held stiffly in such a way as to suggest the possibility of tetanus. Some observers have described as an important symptom marked swelling of the orifice of Stenon’s duct. ”

“ Excessive polypoid tissue hypertrophy should be excised. The less redundant cases subside under galvanocaustic treatment, which may be preceded by tracheotomy and extubation, or the intubation tube may be replaced after the application of the cautery. The former method is preferable since the patient is far safer with a tracheotomic cannula and, further, the constant irritation of the intubation tube is avoided. Subglottic hypertrophic stenosis consists in symmetrical turbinal-like swellings encroaching on the lumen from either side. ”

“ As intimated, especially if the cells of the duct are still in situ, it is impossible to follow the fine nerve-fibres any further. By pressing out the cells from the ducts, one can obtain portion of the duct, with the capillaries belonging to them, but they are short pieces, and the nerve fibril is not easily discoverable. ”

“ All forms of malignant intra-thoracic disease, however, are steadily progressive to a fatal termination. Death commonly arises from the gradual increase in seriousness of the pressure symptoms. Inability to lie down, harassing cough, want of sleep, all tend to induce fatigue which may prove fatal. Deficient aëration of the blood may occasion stupor, or sudden simultaneous pleural and pericardial effusion or general pulmonary oedema may terminate the scene. In exceptional instances death has resulted from laryngeal spasm or from acute hypertrophy of the thyroid gland with tracheal occlusion. ”

“ There; an emergency pressure duct, designed to open automatically in the event of malfunction of the ship's atmospheric regulators. Emergency pressure could be built up through the ducts in the event of any sudden fall of more than eight ounces per square inch; and would be instantly released should it mount more than three pounds above. All he had to do was jam this single duct to the "excess" position and hold his breath.
It was like picking a lock with his bare fingers, and they felt like fat sausages. ”