Lymph: is the name given to tissue fluid after it enters a lymphatic vessel and it contains lymphocytes, fats, and proteins

The function of the lymphatic system (FFF)

• Filtering out the organisms that cause the diseases

• Formation of lymphocytes

• Formation of antibodies

The lymphatic system consists of lymphatic tissues and lymphatic vessels

Lymphatic tissues

They are a type of connective tissue that contains a large number of lymphocytes

They are present in many organs & structures as:

1. Lymph nodes

• They are small oval bodies that are present along the course of lymph vessels.

• They are present mainly in the axilla, groin, neck, and along blood vessels.

2. Spleen

   • Lies in the abdomen behind the stomach. (on the left side of the body)

   • It has a role in filtering the blood and destroying the old RBCs.

   • It acts as a reservoir for the blood as in an emergency it contracts to push blood into circulation.

3. Thymus gland

• It lies in the upper part of the chest behind the sternum.

• It has a role in the formation of T lymphocytes.

4. The tonsils

   • The tonsils form a protective ring of lymphatic tissue around the openings between the nasal and oral cavities and the pharynx.

   • They are mainly 2 tonsils the palatine tonsil which lies in the oropharynx, and the pharyngeal tonsil which lies in the nasopharynx

Clinical notes

• Swelling of the lymph nodes is a sign of the immune system functioning to fight off the invaders of the body as bacteria and viruses.

• Lymphatic vessels provide a pathway for the spread of certain types of malignant tumors from their site of origin.