Section II. Composition and organization of the adipose tissue TISSUE. This tissue consists of masses which vary in their magnitude and shape; in some places they are as large as peas, and even as hazel-nuts. Each of these bodies is composed of grains, and these, when viewed with the microscope, appear to be formed of vesicles, the diameter of which varies from the eight hundredth to the six hundredth part of an inch. The size, which is not the same in all animals, successively increases, according to Wolff, in the hen, in the goose, in man, in the ox, and in the pig. In the different parts of the human body, the size of the vesicles is the same, although that of the masses infinitely varies. They are generally round in form; but in the orbits, in the thickness of the cheeks, in the interior of the pelvis, before the pubes, in the neighbourhood of the kidneys, &c., they are round. In the omentum and appendices epiploicae, the masses are pyramidal or pediculated. Those which are met with in the median line of the abdomen, are ovoid, having one end placed in the skin, and the other in the aponeurosis. The fat under the linea alba sometimes projects through it, and becoming hardened, resembles, in some respects, an omental and ventral hernia. Scarpa states, that he once committed the error of operating on a fatty tumour which he thought was a hernia. The fatty tissue may then be regarded as composed of conglomerated vesicles, which are united into grains, and these in their turn, are collected together to form masses. It is true the parietes of the vesicles are so delicate, that they cannot be anatomically demonstrated; but there are proofs to show, that they actually exist. It would be difficult otherwise to account for the constant and regular forms, which the adipose masses and their component parts present. Haller, and since him Meckel, have said that this form is inherent to fat, and independent of its situation in the cellular tissue. But this is incorrect; for when fat is removed from its containing structure, it possesses no globules with the determined form assigned to them by Haller. If some of these vesicles are placed in tepid water, no oil can be perceived by the microscope on the surface; but when they arc cut, some drops immediately escape, which float on the liquid.* If the fat were contained in the same cells as the serosity, being fluid during life, it ought to obey the laws of gravitation. But this does not take place, for the fat never accumulates in the rectum or penis, in the most extreme cases of obesity, although in anasarca cases those parts are much distended. Again, the water in dropsy, the air in emphysema, and the blood in extravasation of that fluid, recede upon pressure, which produces what is technically called pitting; and the same thing happens in the dead body when oil is thrown into the reticular or cellular membrane; the fluid produces an edematous swelling, and it can be pressed from one part to another, as if it were water. But the natural oil of the adipose membrane, although it may exist in a large quantity, cannot be pressed from one part to another. The preceding circumstances render it most probable that the vesicles do not communicate. Some naturalists have absurdly attributed the formation of the pendulous breasts of some women, and the enlarged nates of others, to the gravitation of the fat. Observations made concerning the vessels of the cellular tissue may be generally applied to those of the adipose substance. The arteries can be readily injected, especially in young subjects — they ramify in the intervening cellular tissue, and end at the microscopic vesicles, where they secrete the fat which the latter contain. The absorbents are less distinct, and their existence is rather admitted from the functions of the tissue than from any anatomical demonstration of them. Miucagni speaks of an external and internal layer of lymphatic vessels, as forming the viniticuli; but he relates no fact in support of this opinion. No nerves have been traced in the reticles, although filaments may be followed in the general cellular substance to a considerable degree of minuteness.* <Callout type="important" title="Fat Distribution Variability">The size and shape of fat masses vary greatly between individuals and species.</Callout> <Callout type="risk" title="Misdiagnosis Risk">Operating on a fatty tumor as if it were a hernia can lead to incorrect treatment.</Callout> <Callout type="gear" title="Microscopic Examination">Observing the structure of fat requires microscopic examination, highlighting the importance of proper tools in medical diagnosis.</Callout>
Key Takeaways
- Adipose tissue is composed of vesicles that vary in size and shape.
- Fat does not accumulate in certain parts of the body, such as the rectum or penis, even in extreme cases of obesity.
- The structure of fat can be studied using microscopic examination.
Practical Tips
- Understand the variability in fat distribution to better assess health risks and conditions.
- Be cautious when diagnosing fatty tumors; they may not behave like other types of hernias.
- Utilize microscopy for accurate diagnosis, as it reveals the true nature of adipose tissue.
Warnings & Risks
- Misdiagnosing a fatty tumor can lead to incorrect treatment and complications.
- Ignoring fat distribution variability can result in misinterpretation of health conditions.
Modern Application
While the chapter provides valuable insights into the structure and function of adipose tissue, modern techniques such as MRI and CT scans offer more precise imaging. However, understanding fat distribution remains crucial for assessing obesity-related risks and diagnosing conditions like lipomas or hernias.
Frequently Asked Questions
Q: What is the significance of the vesicles in adipose tissue?
The vesicles in adipose tissue are significant because they form the basic structure of fat, with each vesicle containing a small amount of fat. Their existence can be inferred from the regular forms and structures observed in adipose masses.
Q: Why does fat not accumulate in certain parts of the body like the rectum or penis?
Fat does not accumulate in these areas because it is not contained within the same cells as serosity (serous fluid). Instead, it remains separate and does not obey the laws of gravitation.
Q: What are the risks of misdiagnosing a fatty tumor?
Misdiagnosing a fatty tumor can lead to incorrect treatment. Operating on what is thought to be a hernia but is actually a fatty tumor could result in unnecessary surgery and potential complications.
Q: How does the variability of fat distribution affect medical diagnosis?
The variability in fat distribution means that doctors must consider individual differences when diagnosing conditions. Misinterpreting the normal variation can lead to incorrect diagnoses, such as mistaking a fatty tumor for a hernia.
Q: What tools are necessary for studying adipose tissue structure?
Studying the structure of adipose tissue requires microscopic examination. Proper tools like microscopes are essential for observing the vesicles and understanding their composition.