Section III: Properties of Fibrous Tissues
In its recent state, this tissue possesses but little elasticity, although when it is dried, this quality becomes very remarkable. The force of resistance to rupture is enormous, and it is owing to this property that the fibrous organs are not susceptible of any considerable or sudden extension.
Thus in inflammation beneath aponeurotic or fasciatic structures, in consequence of their unyielding nature, they compress and aggravate the parts which they cover. But if the force applied be greater than the resistance of these organs, they give way and are lacerated, as happens in various dislocations. On the contrary when the distending force acts slowly, they are not ruptured, but are extended; this is observed in dropsy of the pericardium, or of any of the articulations. They are not capable of suddenly contracting, although they are restored in part to their original state after they have been gradually distended.
These parts possess no animal contractility, so that irritation produces no alteration in their state. Their sensibility has been doubled by many writers, and in the ordinary acceptation of that word, this opinion is probably correct; because if a ligament or tendon be pricked with a needle or cut with a knife, no pain is excited. But it is necessary to bear in mind that the degree and the kind of sensibility vary in different organs according to the particular functions they have to perform. The ligamentous, tendinous, and other similar parts, have no need of that exquisite sensibility which is so essential to the external surface of the body, because they are protected by their deep situation from any direct mechanical irritation; but as the greater part of these organs are liable to be distended and twisted in the violent movements of the limbs, it is necessary that they should be endowed with that species of sensibility, which will enable them to warn the percipient principle when the irritation is carried to an injurious extent. The following experiment illustrates the force of these observations: if one of the joints be completely exposed in a living animal, by removing the surrounding parts, particularly the nerves, it is found that the ligaments may be irritated by chemical or mechanical agents without the animal giving any expression of suffering; but if the same ligaments are forcibly distended and twisted, great pain is produced, and the animal struggles violently.
The uses of the fibrous structures will be noticed in the coming chapters. In the embryo this system is, like all other parts, soft and gelatinous. In infancy it retains much of its leanness and flexibility; it receives a considerable number of blood-vessels, is of a blueish colour, nod is easily dissolved in boiling water. In the adult these organs become more fibrous, dense, and resisting; and these properties are still farther developed in old age, when the ligaments, tendons, &c., losing something of their white and polished appearance, assume a yellowish colour.
Having considered in the preceding pages the common characters of the fibrous system, I shall now describe the peculiarities of its several parts. <Callout type="important" title="Key Property">Fibrous tissues are highly resistant to rupture but lack elasticity when fresh.</Callout> <Callout type="risk" title="Rupture Risk">In cases of sudden force application, fibrous structures like ligaments and tendons can be lacerated or ruptured.</Callout>
Key Takeaways
- Fibrous tissues are highly resistant to rupture but lack elasticity when fresh.
- Inflammation beneath fibrous structures can compress and aggravate the covered parts.
- Sudden force application can lead to lacerations or ruptures of fibrous organs.
Practical Tips
- Understand that sudden movements may cause injury to ligaments and tendons due to their lack of elasticity.
- Recognize that gradual distension allows for safe movement without rupture in conditions like dropsy.
Warnings & Risks
- Fibrous tissues can be lacerated or ruptured if subjected to excessive force, leading to severe injuries such as dislocations.
- In cases where fibrous structures are irritated by chemical agents, the animal may not show signs of pain due to their lack of sensory nerves.
Modern Application
This chapter provides foundational knowledge on the properties and behavior of fibrous tissues in the human body. While medical practices have advanced since 1829, understanding these basic anatomical principles remains crucial for modern emergency responders and survivalists. Knowledge of how ligaments and tendons behave under stress can help prevent injuries and guide appropriate treatment.
Frequently Asked Questions
Q: What happens to fibrous tissues when they are dried?
When fibrous tissues such as ligaments and tendons are dried, their elasticity becomes very remarkable compared to their fresh state.
Q: Why do fibrous structures lack animal contractility?
Fibrous structures like ligaments and tendons have no need for exquisite sensibility because they are protected by their deep situation from direct mechanical irritation. They only require a specific type of sensibility to warn against injurious movements.
Q: What is the significance of the experiment described in this chapter?
The experiment illustrates that while fibrous tissues can be irritated without causing pain if nerves are removed, forcibly distending and twisting them causes significant pain and distress, highlighting their sensitivity to mechanical stress.