Chapter 27 The Lymphatic System 1 The Lymphatic

Chapter 27 The Lymphatic System 1

• The Lymphatic System, Part 1 2

The lymphatic system: • is a secondary transport system • returns tissue fluid from around cells to the blood

Structure 1. Lymph vessels 2. Lymph Nodes 3. Lymph 4

Lymph is made from tissue fluid and contains white blood cells, proteins and fats. Tissue fluid: • is plasma without red cells, platelets or large proteins • surrounds all body cells and helps transport materials in and out of cells Lymph returns to the blood in the subclavian veins (near the collar bones).

Tissue fluid returns to the plasma in two ways: • most enters blood capillaries • some enters dead-ending lymph vessels where it is called lymph. Lymph is later returned to the bloodstream

Lymph vessels & blood vessels 8

Lymph moves in lymph vessels due to: • muscles in the vessel walls • general body movements Valves in lymph vessels control the direction of lymph flow.

L y m p h a t I c S y s t e m 10

Lymph nodes: • are swellings found along lymph vessels • filter bacteria • store lymphocytes (white blood cells). Some of these kill micro-organisms and others produce antibodies.

Lymphatic System Functions 1. Collect tissue fluid and return it to the blood system 2. Fight Infection by (a) Filtering out microorganisms in the lymph nodes (b) Destroying microorganisms by antibody production (c) Mature and store lymphocytes 3. Transport digested fat away from intestine 12

• Video 14 Lymph System 13

Learning check 1 Name three main parts of the Lymphatic System 2 Name three substances dissolved in plasma 3 Name a blood grouping system other than the ABO System 4 What is the function of white blood cells 5 Give two functions of the Lymphatic System 14

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