Marrow bone

“ The short, square, and flattened bones of the body, such as those of the wrist, the skull, and the hips, instead of being hollow inside are spongy; and the spaces in the bone-sponge are filled with a soft tissue called the red marrow in which new red and white corpuscles for the blood are born, to take the place of those which die and go to pieces. ”

“ Although the tissue elements in this disease resemble those of a new growth arising in the marrow, they differ in their arrangement and in their method of growth; there is no tendency to erupt through the cortex of the bone, to invade the soft parts, or to give rise to secondary growths.
_Clinical Features._--The onset of the disease is insidious, and attention is usually first directed to it by the occurrence of fracture of the shaft of one of the long bones--usually the femur--from violence that would be insufficient to break a healthy bone. ”

“ ANIMALS WHICH HAVE NO MARROW.
The marrow seems also to be formed of a similar material; in the young it is of a reddish colour, but it is white in the aged. It is only found in those bones which are hollow, and not in the tibiæ of horses or dogs; for which reason it is, that when the tibia is broken, the bone will not reunite, a process which is effected309 by the flow of the marrow. The marrow is of a greasy nature in those animals which have fat, and suetty in those with horns. ”

“ In the larger bones, the fine oil, by the gentle heat of the body, is exhaled through the pores of its small vesicles, and enters some narrow passages which lead to certain fine canals excavated in the substance of the bone, that the marrow may supply the fibres of the bones, and render them less liable to break. Blood-vessels also penetrate the bones to supply this marrow and this blood; and consequently the marrow is supplied in the infant by means of the umbilical cord. From the marrow diffused, as mentioned above, through the bones, they derive their solidity and strength. ”

“ If the articular surface is extensively diseased, a thin slice of bone should be removed, and if foci in the marrow are then revealed, it is better to gouge them out than to remove further slices of bone, as this involves sacrifice of the cortex and periosteum. ”

“ BONE MARROW. Armour and Company. 7 min., si., color, 16mm. (Animated Hematology, no. 2)
Summary: Points out that the study of bone marrow suggests the diagnosis, treatment, and prognosis of a number of disorders, such as the leukemias, metastic carcinoma, and malaria. ”

“ The soft cellular tumours are composed mainly of spindle or round cells; they grow from the marrow of the spongy ends or from the periosteum of the long bones, the diploë of the skull, the pelvis, vertebræ, and jaws. As they grow they may cause little alteration in the contour of the bone, but they eat away its framework and replace it, so that the continuity of the bone is maintained only by tumour tissue, and pathological fracture is a frequent result. ”

“ The cavity of these bones is filled with a soft white substance called marrow. This is largely fat. Each bone is surrounded by a tough membrane to which the muscles are attached.
Arrangement of the Bones.—The bones of the head form the skull. The other bones of the body not belonging to the limbs make up the trunk. There are over two hundred bones in the entire body. Eight of these form a case for the brain. Fourteen give shape to the face. A chain of twenty-six bones named vertebræ forms the backbone. ”

“ New growths which originate in the skeleton are spoken of as _primary tumours_; those which invade the bones, either by metastasis from other parts of the body or by spread from adjacent tissues, as _secondary_. A tumour of bone may grow from the cellular elements of the periosteum, the marrow, or the epiphysial cartilage. ”

“ The bone marrow loses its fatty constituents, appears red and gelatinous, and contains a greatly exaggerated number of blood-vessels. When heated, the bones do not yield oil as in healthy subjects, and when dry, they seem abnormally porous. ”

“ The outside of the bones is hard, but the inside is soft and hollow. Where there is a joint between two bones, there is a coating of marrow, which may be regarded as a soft bone. The teeth, too, are to be counted among the bones. ”

“ Again the bone, in its nascent stage, enters into the organic principle of bone, and there, by the inherent heat of that principle, is resolved into three factors, viz, its excreted portion goes towards the formation of hairs, mustaches, etc, its thick or condensed portion is assimilated into the organic principle of bone, and its subtile portion is metamorphosed into marrow. ”

“ Dissect out a long bone from one upper and one lower limb and one of the largest ribs. Prepare cultures from the bone marrow in each case. Set aside these bones for the subsequent preparation of marrow films.
24. Film preparations of bone marrow are best made by the Price-Jones method. Seize the bone in a pair of pliers and squeeze out some of the marrow; receive it in a platinum loop, and transfer to a watch glass of dissociating fluid and emulsify. The dissociating fluid is a neutral 10 per cent. solution of glycerine prepared as follows:—
Measure out 10 c.c. ”

“ When there is widespread suppuration in the marrow, and the shaft is extensively bared of periosteum and appears likely to die, it may be resected straight away or after an interval of a day or two. Early resection of the shaft is also indicated if the opening of the medullary canal is not followed by relief of symptoms. In the leg and forearm, the unaffected bone maintains the length and contour of the limb; in the case of the femur and humerus, extension with weight and pulley along with some form of moulded gutter splint is employed with a similar object. ”

“ In bacterial diseases originating in the marrow, if the epiphysial junction is directly involved in the destructive process, its bone-forming functions may be retarded or abolished, and the subsequent growth of the bone be seriously interfered with. ”

“ Only a part of the marrow, the so-called red marrow, is normally occupied by erythroblastic tissue, the rest of the medullary cavity of the bones being taken up by fat. If any long-continued demand for red corpuscles is made, the fat is absorbed, and its place gradually taken by red marrow. ”

“ Finally, this red zone was covered with a fairly thick layer of 42 white bone: this was the layer formed after the madder had been left off.... We shall have no further difficulty in understanding whence transudes the osseous juice that was thought necessary for the formation of callus and the filling-up of the wounds of the bones, now we see that it is the periosteum that fills up the wounds, or is made thick round the fractures, and afterward becomes of the consistence of cartilage, and at last acquires the hardness of bones. ”

“ The limb is often enormously swollen and indurated. The gelatinous effusion beneath the periosteum speedily becomes organised, nodules of osseous matter project into it, and adhere to the surface of the bone frequently by a narrow neck; these increase in number, gradually assume a solid appearance: the bone is thus thickened, often to a very great extent. ”

“ Necrosis, fortunately, seldom occurs in the heads of the long bones, or penetrates the separation betwixt the cancelli of the shaft and the epiphysis. Bits of dead bone in the articular ends, however, very often lead to disease in the joint. ”

“ It consists of two layers, an outer fibrous and an inner cellular layer; the cells, which are called osteoblasts, are continuous with those lining the Haversian canals and the medullary cavity.
The arrangement of the blood vessels determines to some extent the incidence of disease in bone. The nutrient artery, after entering the medullary canal through a special foramen in the cortex, bifurcates, and one main division runs towards each of the extremities, and terminates at the ossifying junction in a series of capillary loops projected against the epiphysial cartilage. ”

“ Where there are two parallel bones--as in the leg, for example--the growth of the diseased bone may be impaired, and the other continuing its normal growth becomes disproportionately long; less frequently the growth of the diseased bone is exaggerated, and it becomes the longer of the two. In either case, the longer bone becomes curved. An _obliquity_ of the bone may result when one half of the epiphysial cartilage is destroyed and the other half continues to form bone, giving rise to such deformities as knock-knee and club-hand. ”

“ If the attachments of the dura mater be strong, and the separation which has taken place between it and the bone be small, the blood effused is compressed by the bone on one side, on which it can exert no influence, and is resisted by the dura mater, which will recede no further on the other. ”

“ When necrosis is extensive, there is a risk of fracture occurring, if motion of the limb be permitted before a sufficient quantity of matter has been effused, before nature has had sufficient time for the consolidation of her substitute, and consequently before the new bone has come to resemble the old in thickness and cohesion. ”

“ Tumours with broad bases, and of soft medullary consistence, attended with extensive change in the structure of the membrane, and softening of the bones and cartilages, grow very rapidly, fill the cavities and expand them, giving rise to great deformity, as seen opposite. They show themselves on the face, through the nostrils—protrude through the floor of the orbit—get into the mouth behind the palate, through the tuberous processes of the superior maxillary bone—or project through the alveolar processes. ”

“ If, on the contrary, there is much displacement, and if that is not entirely removed, intense action ensues both in the soft and hard parts, there is great effusion of new matter, or callus, soft and yielding at first, but gradually becoming hard and dense—bony particles being deposited from the vessels ramifying in the extremities, or in the attached fragments, of the old bone. When detached portions of callus are found lying in the soft parts, a piece of old bone which retained its vitality has generally formed the matrix of the deposit. ”

“ The ossification of the bones on the sides and upper part of the skull, for example, begins by a rounded spot in the middle of each one. From this spot the ossification extends outward in every direction, thus gradually approaching the edges of the bone. When two adjacent bones meet, there will be a line where their edges are in contact with each other, but have not yet united ”

“ The broken extremities of the bones become intimately united by bony matter passing from one to the other. The mass of new bone on the outside, formed by the ossification of the callus, being no longer wanted, is absorbed; by degrees the whole of it disappears, and the bone is left having the same dimensions which it had before the occurrence of the accident.
The process of union is completed in young persons sooner than in those advanced in life; in the upper extremities sooner than in the lower; and in smaller animals more speedily than in man. ”

“ We are not less interested in tracing the formation of bone through its several stages, than in considering other parts of the human system. The formation of the Haversian canals for the passage of blood-vessels to nourish the bones, the earlier construction of bony tissue by a metamorphosis of cartilaginous substance, and also the commencement of ossification at distinct points, called centers of ossification, are all important subjects, requiring the student's careful attention. ”

“ As the muscles and bones have a richer blood supply than the integument, the death of skin and subcutaneous tissues extends higher than that of muscles and bone, with the result that the stump left after spontaneous separation is conical, the end of the bone projecting beyond the soft parts. ”

“ The interment consisted of a quantity of calcined human bones, which lay upon a thin layer of earth at the bottom of the hole, as compactly as if they had at first been deposited within a shallow basket or similar perishable vessel. Upon them lay some fragments of iron, part of two bone combs, and twenty-eight convex objects of bone, like button-moulds.
“The pieces of iron have been attached to some article of perishable material; the largest fragment has a good-sized loop, as if for suspension. ”

“ Thus bones are not dry, lifeless substances, but are the very type of activity and change. In life they are richly supplied with blood from the nutrient artery and from the periosteum, by an endless network of nourishing canals throughout their whole structure. Bone has, therefore, like all other living structures, a self-formative power, and draws from the blood the materials for its own nutrition. ”

“ Bone Formation.—Most of the skull and face bones begin as membranes of connective tissue, that is, are formed in membrane. Bones are also formed in cartilage, the bone formation in this case beginning from centers of ossification, where the deposit of lime salts in the intercellular substance begins, the salts coming to the centers dissolved in the plasma. Such a center of growth in a bone is called the epiphysis and is separated from the main part of the bone or diaphysis by cartilage until full growth is attained, when ossification becomes complete. ”