The Lymphatic System

Question 1

How many litres of interstitial fluid does the lymphatic system collect?

Answer 1

Three litres

Question 2

What does the lymphatic system consist of?

Answer 2

• Fluid (Lymph)
• Vessels (Lymphatics)
• Cells (Lymphocytes and supporting cells)
• Tissues
• Organs

Question 3

Lymphatic tissues consist of:

Answer 3

• Mucosal associated lymphatic tissue (MALT) - including gut/bronchus associated lymphatic tissue GALT and BALT
• Lymphatic nodules (tonsils, peyers patches and veniform appendix)

Question 4

What are the lymphatic organs:

Answer 4

• Lymph nodules
• Thymus
• Spleen

Question 5

Characteristics of lymph nodes:

Answer 5

• Filters as lymph percolates on its way to the vascular system
• Afferent lymphatic vessels enter via the convex surface
• Efferent lymphatics leave via the hilum
• Each node has a feeding artery and draining vein (via the hilum)

Question 6

Characteristics of follicular dendritic cells:

Answer 6

Located in germinal centres

Antigen antibody complexes adhere to their dendritic processes

Follicular dendritic cells cause proliferation of B cells

Question 7

What cells mediate the humoral (blood) immunity?

Answer 7

B lymphocytes

Antibody production by B cells that transform into plasma cells

Question 8

What cells make up the cell mediated response?

Answer 8

T cells

Need antigen presenting cells (macrophages, B lymphocytes) to recognise antigen

Question 9

What cells make up the inflammatory response?

Answer 9

Macrophages and neutrophils

Question 10

Where do the cells come from and how do the lymphocytes reach the lymph nodes?

Answer 10

They enter via the feeding artery and leave via efferent lynphatics. They come from the bone marrow

Question 11

What is lymphadenopathy?

Answer 11

Enlarged lymph nodes

Question 12

What are the immune functions of the spleen?

Answer 12

• Antigen presentation by APCs
• Activation and proliferation of B and T lymphocytes
• Removal of macro molecular antigens from the blood (macrophages)

Question 13

What are the haemopoitic functions of the spleen?

Answer 13

• Removal and destruction of old, damaged and abnormal erythrocytes and platelets
• Retrieval of iron from erythrocytes haemoglobin

Question 14

Splenectomy risks:

Answer 14

Increases risk of infection

Increases risk of DVT and pulmonary embolism

Question 15

What is the role of the thymus?

Answer 15

The maturation of bone marrow derived stem cells into immunocompetent T cells.

(Thymic cell education)