Lymphatic System

Question 1

Lymphatic System

Answer 1

• Involved in fluid that comes out of the blood

* Heavily involved with immune system

Question 2

Lymphatic System contents

Answer 2

• Network of lymph capillaries joined to larger lymph vessels
• Lymph nodes

Question 3

Lymphatic System Function

Answer 3

• Collect fluid that escapes the blood capillaries
• Return that fluid to the circulatory system
• Defence against pathogenic organisms

Question 4

Lymph Vessels

Answer 4

• More fluid will leak out of arteries due to the high pressure that will return to the capillaries and veins
• Excess fluid returned via the lymphatic system is called lymph
• One-way system away from the tissues
• Lymph capillaries start as blind-ended tubes in the spaces between cells of most tissues.
• Slightly larger than blood capillaries

Question 5

Lymph Nodes (Lymph Glands)

Answer 5

• Occur at intervals along the lymph vessels
• Most numerous in the neck, armpits, groin and around the alimentary canal
• Nodes are bean shaped 1-25mm in size
• Each lymph node is surrounded by connective tissue, that extends into the node
• Filter lymphatic fluid and fight against disease and infection

Mass of lymphatic tissue contains:
• Macrophages (WBC)
• Lymphocytes -> WBC -> B lymphocytes or T lymphocytes
• Plasma Cells -> Make antibodies

Question 6

Role of Lymphatic System

Answer 6

• Lymph contains: cell debris, foreign particles and micro-organisms (could be disease causing)
• Large particles (e.g. bacteria) get trapped in meshwork of fibres in lymph nodes
• Large phagocytic (macrophages) destroy these particles by ingesting them and destroying them
with enzymes
• Formation of lymphocytes increases when infections occur - lymph nodes become swollen and sore

Question 7

Other component of the Lymphatic System

Answer 7

• Spleen: acts like a large lymph node
• Bone Marrow: where lymphocytes are formed
• Tonsils: catch harmful bacteria and produce lymphocytes to destroy them
• Thymus: where lymphocytes develop and mature