Homiletics

“ We have seen, that the blood passes from the arteries into the veins, not from the veins into the arteries; we have seen, farther, that almost the whole of the blood may be withdrawn from a puncture made in one of the cutaneous veins of the arm if a bandage properly applied be used; we have seen, still farther, that the blood flows so freely and rapidly that not only is the whole quantity which was contained in the arm beyond the ligature, and before the puncture was made, discharged, but the whole which is contained in the body, both that of the arteries and that of the veins. ”

“ The pumping of the blood through the arteries is assisted by the contractions of the muscular coat, while the elastic tissue, of which it contains a certain amount, gives elasticity to the walls and enables them to stretch and so to accommodate the larger blood supply forced into them at each beat by the heart. The walls of the veins have not the power of contracting and the blood is pushed through more by gravity and the action of the arteries than by any action of their own. ”

“ And then the experiment is easily tried of leaving the vein untouched and only dividing the artery in the neck of a sheep or dog, when it will be seen with what force, in what abundance, and how quickly, the whole blood in the body, of the veins as well as of the arteries, is emptied. But the arteries receive blood from the veins in no other way than by transmission through the heart, as we have already seen; so that if the aorta be tied at the base of the heart, and the carotid or any other artery be opened, no one will now be surprised to find it empty, and the veins only replete with blood. ”

“ Let us take a comparison; the greater the force with which a projectile is thrown into the air, the less influence the weight has in making it deviate; in the case of the blood its influence is still less. ”

“ Now let any one make an experiment upon the arm of a man, either using such a fillet as is employed in blood-letting, or grasping the limb tightly with his hand, the best subject for it being one who is lean, and who has large veins, and the best time after exercise, when the body is warm, the pulse is full, and the blood carried in larger quantities to the extremities, for all then is more conspicuous ”

“ When a weapon passes through a limb, or attaches one part of the body to another, he directs us to cut off the part which projects, and then extraction may easily be accomplished. If fastened in a bone, he advises us to turn it round so as to loosen it ”

“ When blood escapes from a blood-vessel it comes into contact with a foreign surface, either a tissue or the damaged walls of the cut vessel. Very speedily this contact results in the discharge of thrombogen and thrombokinase, the former from the white blood corpuscles and also possibly from the platelets, the latter from the platelets or from the tissue with which the blood comes in contact. The interaction of these two bodies next results in the formation of prothrombin, which, combining with the calcium of any soluble lime salt present, forms thrombin or fibrin-ferment. ”

“ If the Bullet sticks so far in a Bone that it cannot be taken away without breaking the same Bone, it is more expedient to let it lie therein; but if the Leg or Arm-Bones are very much split or shattered, then the Amputation of 'em becomes absolutely necessary. The Pain and Inflammation of the Part may be asswag'd by letting Blood, topical Anodyns, cooling Clysters and Purgations; but in case much Blood hath been already lost, Phlebotomy must be omitted. ”

“ The methods employed by animals increased interest in using artificial methods for letting blood in man.
The devices man has employed to remove blood from the body fall into two major categories: (1) those instruments used for general bloodletting, that is, the opening of an artery, or more commonly a vein, and (2) those instruments used in local bloodletting. Instruments in the first category include lancets, spring lancets, fleams, and phlebotomes. Associated with these are the containers to collect and measure the blood spurting from the patient. ”

“ Tested with nitric acid and ammonia, it is found to contain a protein substance which is called fibrin.
Blood plasma, then, is made up of a fluid portion of serum, and fibrin, which, although in a fluid state in the blood vessels within the body, coagulates when blood is removed from the blood vessels. This coagulation aids in making a blood clot. A clot is simply a mass of fibrin threads with a large number of corpuscles tangled within. The clotting of blood is of great physiological importance, for otherwise we might bleed to death even from a small wound. ”

“ Hence the pulmonary arteries yawn nearest for the blood, and, being short, wide vessels, present the least resistance to the first rush of blood-- mainly venous blood for the right auricle. As they fill up, the back resistance in them becomes equal, and then greater, than the resistance at A, and the rush of blood, now of a mixed quality passes through that aperture. It selects the dorsal aorta, because the carotid arch, plugged by the carotid gland, offers the greater resistance. ”

“ Then the blood is carried to the lungs, where the fresh air you breathe in blows away the “smoke” and makes the blood red again.
The blood is pumped all over the body through tubes or pipes, called blood vessels. Those that carry the red blood out from the heart, we call arteries. They are deep down under the skin, and we cannot see them. The pipes that carry the purple blood from the muscles and other parts back to the heart again, we call veins; and some of these are so close to the surface that we can easily see them through the skin. ”

“ Whenever, on incising an artery, you find blood in the artery, and it runs freely, it indicates that there is a considerable quantity of blood in the arterial system. This blood then should be removed, because, were fluid to be injected into the artery, when it is full of blood and in this congested condition, all of this blood would be pushed ahead of the fluid toward the center of pressure, and from there large quantities would be pushed back into the tissues of the face, which would result in a greatly discolored face and a very poor cosmetic effect. ”

“ But if the divine Galen will here allow, as in other places he does, “that all the arteries of the body arise from the great artery, and that this takes its origin from the heart; that all these vessels naturally contain and carry blood; that the three semilunar valves situated at the orifice of the aorta prevent the return of the blood into the heart, and that nature never41 connected them with this, the most noble viscus of the body, unless for some most important end;” ”

“ The lighter weight and greater mobility of the upper extremity as a whole, as decreasing the resistance to the bullet, were also probably an element in the fact that these effusions were less severe than those in the joints of the lower limb. ”

“ Thus you will be made to gnaw your finger until the blood flows, the blood will then drop on the bones, and if it sinks in, then, indeed, the bones are those of your father; should, however, the blood not soak in, but remain on the surface of the bones, then they are those of a stranger and of no one having any blood-tie with you whatever. ”

“ All reasonable medical men, both of ancient and modern times, have believed in a mutual transfusion, or accession and recession of the blood between the arteries and the veins; and for the sake of permitting this, they have imagined certain inconspicuous openings, or obscure foramina, through which the blood flowed hither and thither, moving out of one vessel and returning to it again. Wherefore it is not wonderful that Riolanus should in various places find that in the ancients which is in harmony with the doctrine of a circulation. ”

“ But if all things be as they are now represented, we shall feel ourselves at liberty to calculate the quantity of the blood, and to reason on its circular motion. Should any one, for instance, in performing phlebotomy, suffer the blood to flow in the manner it usually does, with force and freely, for some half-hour or so, no question but that the greatest part of the blood being abstracted, faintings and syncopes would ensue, and that not only would the arteries but the great veins also be nearly emptied of their contents. ”

“ It is however by the muscular power alone, that they assist in propelling the blood; for the elasticity of their coats can serve no other purpose than preserving the mean diameter of the vessel. If we suppose the arteries to be dilated by the blood, poured into them by the heart, they will, by their contraction, as elastic tubes, undoubtedly propel the blood: but supposing them to be perfectly elastic, the force of the heart will be just as much diminished in dilating them as the force of the blood is increased by their contraction. ”

“ But whatever be the difference of physiognomy, and whatever the difference of temperament, the physiologist tells us that after careful analysis he finds out that the plasma and the disk in the human blood have the same characteristics: so that if you should put twenty men from twenty nationalities abreast in line of battle, and a bullet should fly through the hearts of the twenty men, the blood flowing forth would, through analysis, prove itself to be the same blood in every instance. ”

“ The operation is to commence with first cutting the skin, and then when the bone of a limb is to be sawn, you must not cut through the whole flesh at once, lest an immoderate discharge of blood take place from the veins and arteries so as to occasion the death of the patient and interrupt the process of sawing the bone; except the flesh of the limb be wasted or putrid. ”

“ Infantry, and all the other branches, in a healthy body—and our own body is healthy. Watch our phagocytes come forward now, just as those tiny white corpuscles rush through the blood to an invaded spot. ”

“ The coagulation of the blood, while it is a matter of fundamental importance in physiology, has peculiar interest for the surgeon, on account of the special feature of coagulability of inflammatory exudations and the part played by lymph in the healing of wounds and various other pathological phenomena, such as the sealing of divided arteries by blood-clot. ”

“ In this passage every fragment of the body has been bathed in blood. This stream rushing through the capillaries contains the material from which bone, muscle, and brain are made, and carries away all the waste material which must be thrown off.
The actual work of making bone or muscle is performed outside of the blood in the tissues. You say, the capillaries are closed, and how can the blood get to the tissues? It will be necessary here to speak of a certain property of membranes in order that you understand how the tissues are built up by the blood apparently closed within the veins. ”

“ The millions of blood cells whose duty it is to do the repair work arrive on the scene on the "double-quick" and at once begin to again connect the tissues, displaying the most wonderful intelligence and activity in their work. The cells of the tissues, nerves, blood vessels, on both sides of the wound, begin to increase and multiply, bringing into being millions of new cells, which, advancing from both sides, finally meet in the center of the wound. ”

“ Carry fresh, warm, invigorating blood in your veins to inject into the veins of the world. This is far safer and nobler than sticking the lance into the swollen veins of the world, to draw forth its putrid blood for your own use. ”

“ The mode of displacement of the lateral fragments when a wide shaft such as that of the femur is struck, throws some light on that of the displacement of soft tissues such as the component parts of a perforated nerve or artery. The bullet, passing through, expends the chief part of its energy in driving before it the fragments produced in its direct course, while a minor part of the energy is expended on displacing the lateral fragments, which are pushed to either side without becoming separated from their periosteal attachment. ”

“ In experiments upon animals, it has always been found that the power of the constitution, in resisting the effects of the injection of pus into the veins, was much greater at the first than at any subsequent operation. This circumstance would appear to associate itself directly with the observations now made, and to afford another illustration of the power of healthy blood in resisting the entrance of some foreign matters into the system. ”

“ That a blunt instrument, like the small end of a ramrod, should be forced between the loose viscera of the abdomen without wounding any of them, may be easily conceived, but that balls or sharp-pointed swords should do so, is not to be understood so easily. ”

“ Within the thoracic cavity anterior to the heart note a mass of pinkish tissue, the thymus gland. Observe the large masseter muscles, which cover the jaws. What is their function? On either side of the neck lies a large blood-vessel, the external jugular vein, which collects blood from the head and carries it down to the heart. Note the large pectoral muscles which cover the breast and extend out into the arms, and which are so strong and highly developed in the sparrow. The head is supported by large muscles which run down the back of the neck to the ribs. ”