Frequently Asked Questions

What do the following medical terms mean?

 Adhesions

Adhesions are abnormal bands of tissue. They may be thought of as internal scar tissue. In the case of frozen shoulder (also known as adhesive capsulitis) adhesions grow between the shoulder joint surfaces, restricting motion.

 Areolar tissue

Areolar tissue is formed throughout the body in loose sheets around blood vessels, nerves and tendons; as a soft pliable substance it helps to fill the spaces between larger organs. The tissue is made of a mixture of collagen, elastic and reticulin fibres. Under the skin and face it contains a large amount of mobile, elastic fibres, in contrast to the palms of the hands and soles of the feet, which are tough and contain more collagen fibres.

 Extravasation

Extravasation refers to the leakage of a fluid out of its container. In the case of inflammation, it refers to the movement of white blood cells from the capillaries to the tissues surrounding it.

 Fascia

A s pecialized connective tissue layer which surrounds muscles, bones, and joints, providing support, protection and giving structure to the body.

Induration

Any pathological hardening or thickening of tissue.

 Inflammation

Inflammation has two main components: cellular and exudative. The cellular component involves the movement of white blood cells from blood vessels into the inflamed tissue. The white blood cells, or leukocytes, take on an important role in inflammation; they extravasate (filter out) from the capillaries into tissue, and act as phagocytes, picking up bacteria and cellular debris. They may also aid by walling off an infection and preventing its spread. The exudative component involves the movement of fluid, usually containing many important proteins such as fibrin and antibodies. Blood vessels are dilated upstream of an infection (causing redness and heat) and constricted downstream while capillary permeability to the affected tissue is increased, resulting in a net loss of blood plasma into the tissue, giving rise to edema or swelling. The swelling distends the tissues, compresses nerve endings, and thus causes pain.

 Lymphatic system

The lymphatic system is a major component of the immune system, with three interrelated functions:

  1. Removal of excess fluids from body tissues
  2. Absorption of fatty acids and their subsequent transport to the circulatory system
  3. Production of immune cells.

It acts as a secondary circulatory system, except that unlike the circulatory system, the lymphatic system is not closed and has no central pump; the lymph moves slowly and under low pressure due to peristalsis, the operation of semilunar valves in the lymph veins, and the milking action of skeletal muscles. Like veins, lymph vessels have one-way valves that depend mainly on the movement of skeletal muscles to squeeze fluid through them. Rhythmic contraction of the vessel walls may also help draw fluid into the lymphatic capillaries. This fluid is then transported to progressively larger lymphatic vessels that drain into the circulatory system.

 Lymph

Lymph originates as blood plasma that leaks from the capillaries of the circulatory system, becoming interstitial fluid, and filling the space between individual cells of tissue. Most of the fluid is returned to the capillaries, but the excess interstitial fluid is collected by the lymphatic system by diffusion into lymph capillaries, and is processed by lymph nodes prior to being returned to the circulatory system. Once within the lymphatic system the fluid is called lymph, and has almost the same composition as the original interstitial fluid.