Lymphatic system (Chapter 5) Flashcards
1
Q
What are the main functions of the lymphatic system?
A
- To collect the fluid that escapes from the blood capillaries and return it to the circulatory system. - The lymphatic system is also an important part of the body’s internal defence against diseases.
2
Q
What does the lymphatic system consist of?
A
- Lymph capillaries
Lymph capillaries are slightly larger and more
permeable than blood capillaries - Lymph vessels
blind-ended tubes found in the spaces between the cells of most tissues. They are ‘vein-like’ in that lymph travels at a relatively low pressure and they have valves that prevent backflow. - 2 lymphatic ducts
which empty the lymph into large veins in the upper chest - Lymph nodes/glands
found in the intervals along the lymph vessels
3
Q
Where are lymph nodes found, what is their structure and what surrounds them?
A
- Most lymphatic nodes are found in the neck, armpits, groin and alimentary canal.
- Each node is surrounded by a framework of connective tissue, containing lymphoid tissue which ‘house’ lymphocytes, phagocytes and plasma cells.
4
Q
How does the lymphatic system defend against disease?
A
- Large particles such as bacteria get trapped in meshwork of fibres in lymph nodes
- Large phagocytes destroy these particles by ingesting them and destroying them with enzymes
- Formation of lymphocytes increases when infections occur causing the lymph nodes to become swollen and sore
5
Q
Where are lymphocytes formed?
A
In the bone marrow
6
Q
Where do lymphocytes develop and mature?
A
Thymus
7
Q
Define lymph
A
Excess fluid in the tissues returned to the blood by the lymphatic system
8
Q
What is the importance of valves in the lymphatic system?
A
Valves help facilitate the movement of lymph and maintain the proper direction of flow. They also prevent the backflow of lymph and helps maintain the proper circulation of the fluid.
