Physical Properties
- Lymph is a white vascular connective tissue.
- It is a highly translucent, alkaline fluid present in the lymph vessels and between the blood capillaries and the tissues.
- It also forms the tissue fluid which surrounds the body tissues.
- The fluid that flows through the lymphatic system is called lymph tissue fluid.
- It is helpful in the maintenance of fluid balance.
Lymphatic System
Body fluids are the medium of supply in the body. In the average 70 kg adult, human total body water is about 60 per cent of the body weight or about 42 litres. Two types of body fluids are:
- Intracellular Fluid: It is present inside the body cells. About 28 of the 42 litres of fluid in the body is inside the 75 trillion cells. The intracellular fluid contains a large amount of potassium and phosphate ions and proteins, moderate quantities of magnesium and sulphate ions and only small quantities of sodium and chloride ions and almost no calcium ions.
- Extracellular Fluid: The extracellular fluid is mainly present as interstitial fluid and blood plasma. The interstitial fluid (tissue fluid) is about 11 litres and plasma contributes about 3 litres in a normal adult. Plasma includes blood plasma and lymph plasma. Lymph plasma is similar to blood plasma except that lymph plasma has lower protein content. The interstitial fluid surrounds each cell. The plasma is the noncellular part of the blood and communicates continuously with the interstitial fluid through the pores of the capillary membranes. These pores are permeable to almost all solutes in the extracellular fluid except proteins.
Transcellular fluid is known as a specialized type of extracellular fluid. All the transcellular fluids together constitute about 1 to 2 litres.