Blood is a fluid connective tissue. It is an extremely complex substance carrying a wide variety of cells and substances to all areas of he body. Blood is often described as seat of the soul since it performs several vital functions of the body . A normal healthy man has about 5.5 litres of blood.
Blood is formed of plasma and formed elements such as RBC, WBC and blood platelets
Functions of blood
- Regulate body temperature.
- Maintains a constant pH and water balance
- Defence against pH and water balance
- Transport digested food materials, respiratory gases and waste materials
Lymphatic system consists of lymph and lymph vessels (lymphatics). The fluid in the spaces between tissue cells is called interstitial fluid or tissue fluid or extra cellular fluid.
Lymph (L. lympha, clear water) a colourless fluid derived from blood by filtration through capillary walls in the tissues.
Lymph is found not only in he lymphatic vessels and bathing the cells of the body, but also in the various cavities of the body, such as coelomic cavity, the pleural cavities, the pericardial cavity, the cavities at the joints etc, where it serves as a lubricant.
Functions of Lymph
- Lymph serves as the middle man between the blood and tissues.
- Transport digested fats, fat soluble vitamins etc
- Filtration and disposal of bacteria and other foreign particles
- Storage of immunologically competent cells (lymphocytes)
- The lymph also carries absorbed fats and lipids from small intestine to the blood in the form of droplets called chylomicrons.
Blood vs Lymph
1. Red coloured
2. Blood circulates in the closed circuit
3. Blood vascular system consists of blood, arteries, veins and heart.
4. Blood vascular system is the main transporting system of the body
5. Presence of RBC
6. High protein concentration
7. More nutrients and wastes
2. It is the extracellular fluid that circulates through the tissue spaces into blood vascular system
3. Lymphatic system consists of lymph, lymph capillaries lymph nodes and lymph vessels
4. It serves as parallel transporting system
5. Absence of RBC
6. Low protein concentration
7. Contains less nutrients and wastes.