Characteristics of connective tissue

There are many aspects of the body that we know well: what they do, where they are and what happens when they go wrong. We can confidently predict what diseases will occur if these major bodily structures fail. As both patients and healthcare practitioners, we see these structures mentioned frequently and many can exist in everyday conversation.

However, there is another part of the body whose function is less widely-known. Binding together the major components of the body, the connective tissue is a vital piece of bodily integrity. The function and characteristics of connective tissue are not as widely communicated as previously mentioned structures, yet it has important roles that can lead to profound disease states. Understanding what connective tissue is, how it works and how it can go wrong is key to providing a thorough picture of how the body works- and providing your patient with answers to their health issues.

 

What is connective tissue?

Connective tissue is a broad term that describes a wide variety of specialised biological material widely distributed throughout the body. Using the analogy of a house, if cells are the bricks, then connective tissue can be thought of as the cement that binds the cells of the body together.

Its development begins during the development of the foetus. Depending on the location, different growth signals are released which lead to the specialisation of connective tissue in different compartments. This specialisation continues as we grow and develop, meaning the integrity of connective tissue in the body is intimately linked with our health.

 

What are the types of connective tissue?

The three main categories of connective tissue (CT) are loose connective tissue, dense connective tissue, and specialised connective tissue [1].

Loose CT and dense CT are made up of the three same basic structures: collagen fibres, elastin fibres and reticular fibres. Collagen fibres are perhaps most well-known by patients as many cosmetic products contain collagen due to its role in skin integrity. In addition, collagen is arranged differently in loose CT compared to dense CT; in dense CT, the collagen fibres are closely packed together to increase tensile strength.

Elastin fibres are found where elastic recoil is important, such as distensible structures (e.g., large arteries). In these structures, elastin in connective tissue enables the overall structure to expand and then recoil back to shape, contrasting the strong (but inelastic) collagen fibres. Reticular fibres can be thought of as similar to collagen fibres, in that they provide structural support, but also contain spaces that enable fluid and soluble molecules to pass through.

The relative quantities and physical arrangement of these three basic structures determine the properties of the CT. For example, tendons need to be very strong with little elasticity as they are required to efficiently transfer large amounts of force. For this reason, they contain large amounts of densely-packed collagen fibres. However, structures such as the lungs need to be able to expand and then recoil, thus the CT here contains large amounts of elastin.

 

What is specialised connective tissue?

The third type of connective tissue is specialised CT. Examples of this include adipose tissue, cartilage, bone, blood, and lymph [1]. Rather than simply containing different quantities of fibrous proteins, specialised CT comprises highly variable cells that provide specific characteristics.

Adipose tissue is further subdivided into white and brown. White adipose tissue is our body’s main store of fat and provides organ protection and warmth. Brown adipose tissue is so-called due to a large number of mitochondria in the fat cells which generate heat through metabolic processes.

Bone and cartilage are highly specialised structures that must be strong but flexible enough to withstand force. The structure of bone is unique in that it contains collagen fibres to absorb energy, but also a mineralised matrix of cells that give substantial strength and structural support [2]. This delicate balance can be seen in diseases such as osteoporosis, where reduced bone density results in much weaker, fragile bones that fracture easily [2].

Cartilage is a strong, elastic type of specialised CT found in joints and important bony areas, such as the spine. The most classic cartilage type is hyaline cartilage which is found in joints such as the knee; the balance between strength, energy absorption and low-friction gliding means hyaline cartilage is extremely specialised [3]. Once again, the crucial characteristics are best demonstrated in disease states such as osteoarthritis where the progressive wearing of cartilage and articular surfaces results in reduced joint function and pain.

 

Connective tissue and health

As you may have inferred, the connective tissue is far from the simple, fibrous structure we tend to imagine; it comprises a wide variety of structures from tough, inflexible tendons to spongy adipose tissue, to specialised nerve fibres and blood cells.

Due to its widespread and highly variable functions in the body, disease states can be caused by, or exacerbated by, problems with connective tissue. This is due to the complex interactions between connective tissue, body cells and the immune system, which are linked by the extracellular matrix (ECM).

The ECM is the metabolically active fluid that surrounds our cells and contains specialised structures based on where in the body it is found. It is an extremely complex system that has structural functions (through proteins such as collagen), homeostatic functions and links to the immune system [4]. Importantly, disease states such as chronic inflammation can cause changes in the ECM, such as adding acidity, which can compromise the delicate balance between functions and disrupt body homeostasis.

Our Med matrix has been specially developed to identify and treat issues with body tissues and the ECM, helping to detoxify your patients. Using three proven techniques working synergistically, you can help the repair process for your patients in just fifteen minutes, removing long-standing damage from inflammation and toxins.

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Author: Hardeep Lotay (Final Year Medical Student at Cambridge University, blogger, writer)

 

Bibliography

[1] Kamrani P, Marston G, Jan A. Anatomy, Connective Tissue. [Updated 2021 Jan 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538534/

[2] Weatherholt, A. M., Fuchs, R. K., & Warden, S. J. (2012). Specialized connective tissue: bone, the structural framework of the upper extremity. Journal of hand therapy: official journal of the American Society of Hand Therapists, 25(2), 123–132. https://doi.org/10.1016/j.jht.2011.08.003

[3] Abhijit M. Bhosale, James B. Richardson, Articular cartilage: structure, injuries and review of management, British Medical Bulletin, Volume 87, Issue 1, September 2008, Pages 77–95, https://doi.org/10.1093/bmb/ldn025

[4] Frantz C, Stewart KM, Weaver VM. The extracellular matrix at a glance. J Cell Sci. 2010;123(Pt 24):4195-4200. doi:10.1242/jcs.023820

 

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