Body cavity

“ Secondly, the body-cavity when it appears in the mesoblast plates, does not arise as a single cavity, but as a pair of cavities, one for each plate of mesoblast, and these cavities remain permanently distinct in some parts of the body, and nowhere unite till a comparatively late period. Thirdly, the primitive body-cavity of the embryo is not confined to the region in which a body-cavity exists in the adult, but extends to the summit of the muscle-plates, at first separating parts which become completely fused in the adult to form the great lateral muscles of the body. ”

“ In addition to forming the organs, the tissues are also grouped in such a manner as to provide supports for organs and to form cavities in which organs are placed. The various cavities of the body are of particular interest and importance. The three largest ones are the cranial cavity, containing the brain; the thoracic cavity, containing the heart and the lungs; and the abdominal cavity, containing the stomach, the liver, the intestines, and other important organs (Fig. 2) . Smaller cavities serving different purposes are also found.
[pg 008] ”

“ In a simple case of this kind little or nothing is effused into the cavity or secreted from the membranes of the chest, which will interfere with the processes which may have happily begun, and which it is desirable should be aided by the absolute quiescence of the patient, to whom no medicine should be given which may render any movement of the body necessary. ”

“ The digestive organs in early age preponderate considerably over the respiratory organs; whereas, on the contrary, in the healthy and well-formed adult, the thoracic cavity and organs of respiration manifest a greater relative proportion to the ventral cavity and organs. At the adult age, when sexual peculiarities have become fully marked, the thoracic organs of the male body predominate over those of the abdomen, whilst in the female form the ventral organs take precedence as to development and proportions. ”

“ That portion of the trunk which in man commences beneath, and in mammalia behind, the diaphragm, and terminates at the extremity of the pelvis. The abdominal cavity is the largest in the human body. It is lined with a serous membrane, called the peritoneum. ”

“ The cavity of the mouth is actually larger than that of the body, thorax and abdomen together. The upper jaw is very narrow, but greatly arched from before backwards, to increase the height of the cavity and allow for the great length of the whalebone-blades ”

“ The advantage of this arrangement is, of course, in the very large surface which it gives; every one of the individual lung sacs has its wall filled with capillaries and there are so many of the tiny individual sacs that the total surface over which the blood is spread is measured in hundreds of square feet. We cannot imagine any other arrangement by which so large a surface of exposure could be packed away into a cavity the size of the human chest. ”

“ Those, that are seated in the eyes, or in the gums, the nostrils or the exterior angle of the eye, or in the cavity of the ears, abdomen or the umbilicus, or about any suture of the body, hips, ribs, arm-pits, chest, breasts, sides, or the joints, as well as those, that secrete frothy blood or pus with a gurgling sound, or contain any foreign matter embedded in their inside, are healed only with the greatest difficulty. ”

“ First, other congeries of glands occupy but a particular part of the system, or constitute a particular organ, as the liver, or kidneys; but those glands, which secrete the mucus, and perspirable matter, which are called capillaries, are of very great extent; they receive the blood from the arteries, separate from it the mucus, which lines every cell, and covers every cavity of body; and the perspirable matter, which softens and lubricates the whole surface of the skin, and the more extensive surface of the air-vessels, which compose the lungs. ”

“ This regularity is found too only in the human skeleton. The animals are irregular men. (Vide Oken's Zahlengesetz in den Wirbeln. Isis, 1829, S. 306.)
Cavities of the Trunk.
2115. The osseous system forms the trunk or body, because it follows the vascular system; the two other galvanic systems, the dermal and intestinal systems, form the large portions of the trunk or its cavities; to them is added the sexual cavity or pelvis.
2116. There are thus three truncal cavities, a pulmonary, an intestinal, and a sexual cavity, or thoracic, abdominal, and pelvic cavity. ”

“ The left side of the body is cut away to the median plane so as to expose the abdominal and pericardial cavities and the neural canal in their whole length. The alimentary canal and the liver have been drawn downwards, and the oral cavity, the pharynx, part of the intestine, and the cloaca have been opened. The cartilaginous parts of the skeleton are dotted, and the calcified portions of the vertebral centra are black. abd.cav, Abdominal cavity; au, auricle; b.br, basi-branchial; b.hy, basi-hyal; c.art, conus arteriosus; cd.a, caudal artery ”

“ In all other Tunicata, an atrial cavity is formed by involu tion of the ectoderm, which thus gives rise to a cavity on each side of the branchial sac, into which the branchial clefts of the adult open ; and a thick cellulose cuticula, into which cells from the ectoderm usually wander, invests the exterior of the body. ”

“ In man and the other mammals (but only in these) this cœloma divides, when fully developed, into two different cavities, which are separated by a transverse partition—the muscular diaphragm. The fore or pectoral cavity (pleura-cavity) contains the œsophagus (gullet) , heart, and lungs; the hind or peritoneal or abdominal cavity contains the stomach, small and large intestines, liver, pancreas, kidneys, etc. ”

“ If we pursue our researches into the interior of this animal, we find within the framework of the skeleton a great cavity, or rather, I should say, two great cavities,–one cavity beginning in the skull and running through the neck-bone, along the spine, and ending in the tail, containing the brain and the spinal marrow, which are extremely important organs. The second great cavity, commencing with the mouth, contains the gullet, the stomach, the long intestine, and all the rest of those internal apparatus which are essential for digestion ”

“ Mouth Cavity in Man.—In our study of a frog we find that the mouth cavity has two unpaired and four paired tubes leading from it. These are (a) the gullet or food tube, (b) the windpipe (in the frog opening through the glottis) , (c) the paired nostril holes (posterior nares) , (d) the paired Eustachian tubes, leading to the ear. All of these openings are found in man.
In man the mouth cavity, and all internal surfaces of the food tube, are lined with a mucous membrane. The mucus secreted from gland cells in this lining makes a slippery surface so [Pg 301] that the food may slip down easily. ”

“ The teeth.—Imperfect use of the teeth leads to many ills. When adequately exercised and made to execute for one or two hours every day a lively dance in their sockets, during which the circulation of blood and lymph in the tooth-pulp, periodontal membrane, and surrounding tissue of the gum is vigorously stimulated, and the cavity of the mouth is bathed in a copious flow of salivary and other buccal secretions, we have conditions which make alike for the health of the buccal mucous membrane, of the teeth, and of the periodontal membrane and alveoli ”

“ The assumption of peritoneal adhesion, and consequent obliteration of serous areas, offers many advantages in considering the adult human abdominal cavity, especially from the standpoint of comparative anatomy. ”

“ In the chambers of the eye, water, as being a product of digestion, is constantly secreted; the orbitar cavity is a mouth with salivary glands, giving tears; the lachrymal canal is a bronchial duct, which opens into the nose like the Eustachian tubes did from the ear into the mouth; the eye-lids correspond to the lips, and are, in like manner, fringed with hairs; indeed, this little organ repeats in itself the whole of man, which is the highest and most complete organization. ”

“ It is painful, tender, advances rapidly to maturity, becomes conical, and finally bursts and discharges bloody "matter." Through the opening, and filling the cavity, may be seen a piece of sloughing cellular tissue which is called the core. ”

“ These cavities are known as the infundibular or subgenital cavities. They serve probably for the aeration of the gonads by admitting to their vicinity water with its dissolved oxygen; they never serve as genital ducts, since the generative products are always dehisced into the stomach and pass out by the mouth. In some genera, for instance, Cyanea and its allies the gonad as a whole protrudes through the subgenital cavity as if it had undergone a hernia, and hangs down in the subumbral space as if suspended by a mesentery (fig. 15) . ”

“ When we are about to take a long breath, the muscles pull upon the sides of the chest in such a way as to draw them apart. At the same time the diaphragm draws itself downward. By these means, the cavity of the chest is made larger and air rushes in through the nose or mouth to fill the space. ”

“ The mucus which constantly forms on the lining membrane of the nose and the little hairs in the nostrils, act as screens, preventing dust being breathed into the lungs. The pharynx is the cavity behind the nose, mouth and larynx. ”

“ They adhere to one another end to end, and become flattened, or lengthened, or ramified; or they unite and form one common cavity, keeping their walls only at points where they are not in contact, thus forming tubes, or fibres, as, for example, in the histological elements of muscles and nerves. ”

“ The little visceral cavity contains the complex groups of muscles for opening and closing the valves, a simple stomach, a large granular liver, a short intestine, two hearts, and the centre of the nervous system. ”

“ It is possible also that the same larvæ which are free in the oral cavity when the food is being eaten migrate into the nasal cavities. After being stationary a fresh skin is formed and the spine-bearing cuticula are thrown off. ”

“ Collect a further sample of blood or serum for subsequent investigation as to the presence of antibodies.
Peritoneal Cavity.—
16. Sear a broad track in the middle line of the abdominal wall; open the peritoneal cavity by an incision in the centre of the seared line. Observe the condition of the omentum, the mesentery, the viscera and the peritoneal surface of the intestines.
17. Collect a specimen of the peritoneal fluid (or pus, if present) in a capillary pipette. Make cultivations, tube and surface plate, and cover-slip preparations from this situation. ”